PLANT-GROWING TRAY AND METHOD

Abstract

A plant-growing tray comprises a tray top and a plurality of cells extending downwardly from the tray top. Each cell is for containing a substrate for a plant, for the propagation or growth of the plant. Each cell is associated with a catchment area of the tray top, and each catchment area has a sloped surface which, during watering of the plants in the tray, directs water impinging or falling on the catchment area towards the cell.

Claims

1. A plant-growing tray comprising a tray top and a plurality of cells extending downwardly from the tray top, each cell for containing in use a substrate for a plant; wherein each cell is associated with a catchment area of the tray top having a sloped surface configured such that, in use, water impinging on the catchment area is directed towards the cell.

2. A plant-growing tray according to claim 1, wherein each cell is surrounded by its associated catchment area.

3. A plant-growing tray according to claim 1 or 2, wherein each catchment area is associated with only one cell.

4. A plant-growing tray according to any of claims 1 to 3, wherein the area of each catchment area is equal.

5. A plant-growing tray according to any of the preceding claims, further comprising a perimeter rib extending upwardly from the tray top along at least portion of, preferably all of, a perimeter of one or more of the catchment areas, preferably each catchment area.

6. A plant-growing tray according to any of the preceding claims, further comprising a plurality of ventilation holes defined through the tray top, at least one of the ventilation holes being located between adjacent catchment areas.

7. A plant-growing tray according to claim 6, wherein the ventilation hole located between adjacent catchment areas is bounded by a perimeter rib.

8. A plant-growing tray according to any of the preceding claims, wherein each cell comprises a plurality of projections spaced around and extending inwardly into the cell for, in use, supporting an upper portion of a stabilized medium; wherein an upper surface of each projection is preferably level with or lower than an adjacent portion of the catchment area.

9. A plant-growing tray according to claim 8, wherein the at least one of the projections is configured such that, in use, water directed by the catchment area flows over the upper surface.

10. A plant-growing tray according to claim 8 or 9, wherein at least one of the projections is configured such that, in use, water flowing over the upper surface of the projection impinges upon the stabilized medium.

11. A plant-growing tray according to any of claims 8 to 10, wherein the upper surface of at least one of the projections, and preferably of each projection, slopes downwardly into the cell towards the stabilized medium in use.

12. A plant-growing tray according to any of claims 8 to 11, wherein the upper surface at least one of the projections, and preferably of each projection, is shaped to form a channel.

13. A plant-growing tray according to any of claims 8 to 12, wherein the sloped upper surface of at least one of the projections, and preferably of each projection, is shaped to form an upper reservoir.

14. A plant-growing tray according to claim 13, in which the upper reservoir is shaped so that a portion of the upper reservoir has a high aspect ratio, being a ratio of the minimum lateral dimension of the reservoir portion to the maximum radial depth of the reservoir portion.

15. A plant-growing tray according to any of claims 8 to 14, wherein the tray comprises a plurality of upstanding ribs, the upstanding ribs extending around each cell between adjacent projections.

16. A plant-growing tray according to any of claims 8 to 15, wherein each catchment area is shaped such that in use water is directed to the upper surface of each of the plurality of projections.

17. A plant-growing tray according to claim 16, wherein the catchment area is shaped such that in use an equal amount of water is directed to each of the plurality of projections when water uniformly impinges on the catchment area.

18. A plant-growing tray according to any of claims 8 to 16, wherein each cell comprises a lower reservoir defined between adjacent projections wherein, in use, water flowing into the lower reservoir impinges on a lower portion of the stabilized medium.

19. A plant-growing tray according to claim 18, in which the lower reservoir is shaped so that a portion of the lower reservoir has a high aspect ratio, being a ratio of the minimum lateral dimension of the reservoir portion to the maximum radial depth of the reservoir portion.

20. A plant-growing tray according to any preceding claim, in which the tray is formed as a single piece.

21. A cell insert for a plant-growing tray, comprising a tray-top portion and a cell extending downwardly from the tray-top portion, the cell for containing in use a substrate for a plant, wherein the tray-top portion provides a catchment area for the cell, having a sloped surface configured such that, in use, water impinging on the catchment area is directed towards the cell.

22. A cell insert according to claim 21, receivable in a cell of a plant-growing tray according to any of claims 1 to 20.

23. A cell insert according to claim 22, in which when a cell insert is received in each cell of the plant-growing tray, the tray-top portions of the cell inserts abut to form a tray top in which each cell is associated with a catchment area of the tray top.

24. A cell insert according to claim 23, in which a plurality of cell inserts received in the cells of the plant-growing tray form a tray as defined in any of claims 1 to 19.

25. A method for watering plants in a plant-growing tray or a cell insert as defined in any preceding claim, in which water is provided from above the tray or cell insert, and water which falls onto the tray top or tray-top portion is directed from each catchment area into a cell associated with that catchment area.

Description

DESCRIPTION OF SPECIFIC EMBODIMENTS

[0074] Specific embodiments of the invention will be now be described by way of example, with reference to the accompanying drawings in which:

[0075] FIG. 1 is a three-quarter view from above of a portion of a plant-propagating tray according to a first embodiment of the invention;

[0076] FIG. 2 is a top view of a portion of the plant-propagating tray shown in FIG. 1;

[0077] FIG. 3 is a first vertical section of a single cell of the plant-propagating tray shown in FIGS. 1 and 2, sectioned at 45 degrees to an edge of the tray;

[0078] FIG. 4 is a second vertical section of the single cell of the plant-propagating tray shown in FIGS. 1 and 2, sectioned parallel to the edge of the tray;

[0079] FIG. 5 is a three-quarter view from above of a portion of a plant-propagating tray according to a second embodiment of the invention;

[0080] FIG. 6 is a top view of a portion of the plant-propagating tray shown in FIG. 5;

[0081] FIG. 7 is a first vertical section of a single cell of the plant-propagating tray shown in FIGS. 5 and 6, sectioned at 45 degrees to an edge of the tray;

[0082] FIG. 8 is a second vertical section of the single cell of the plant-propagating tray shown in FIGS. 5 and 6, sectioned parallel to the edge of the tray;

[0083] FIG. 9 is a vertical section of a single cell of a plant-propagating tray according to a third embodiment of the invention;

[0084] FIG. 10 is a vertical section of a single cell of a plant-propagating tray according to a fourth embodiment of the invention; and

[0085] FIG. 11 is a three-quarter view from above of a portion of a plant-propagating tray according to a fifth embodiment of the invention;

[0086] FIG. 12 is a vertical section of two adjacent cells of the plant-propagating tray shown in FIG. 11, sectioned parallel to an edge of the tray;

[0087] FIG. 13 is a three-quarter view from above of a portion of a plant-propagating tray according to a sixth embodiment of the invention;

[0088] FIG. 14 is a three-quarter view from above of a portion of a plant propagating tray according to a seventh embodiment of the invention;

[0089] FIG. 15 is a three-quarter view from above of the portion of a plant propagating tray of FIG. 14, viewed from a higher angle;

[0090] FIG. 16 is a top view of the portion of a plant propagating tray shown in FIGS. 14 and 15;

[0091] FIGS. 17 and 18 are vertical sections of a single cell of the plant-propagating tray shown in FIGS. 14 to 16, sectioned at 45 degrees to an edge of the tray, respectively without and with a stabilized medium in the cell;

[0092] FIGS. 19 and 20 are vertical sections of a single cell of the plant-propagating tray shown in FIGS. 14 to 16, sectioned parallel to an edge of the tray, respectively without and with a stabilized medium in the cell;

[0093] FIG. 21 is a three-quarter view of a portion of a plant-propagating tray according to an eighth embodiment of the invention, similar to the tray of the seventh embodiment but of shallower cell depth;

[0094] FIG. 22 is a three-quarter view of a portion of a plant-propagating tray according to a ninth embodiment of the invention;

[0095] FIGS. 23 and 24 are vertical sections of a single cell of the plant-propagating tray shown in FIG. 22, sectioned at 45 degrees to an edge of the tray, respectively without and with a stabilized medium in the cell;

[0096] FIGS. 25 and 26 are vertical sections of a single cell of the plant-propagating tray shown in FIG. 22, sectioned parallel to an edge of the tray, respectively without and with a stabilized medium in the cell;

[0097] FIG. 27 is a three-quarter view of a portion of a plant-propagating tray according to an tenth embodiment of the invention, similar to the tray of the ninth embodiment but of greater cell depth;

[0098] FIG. 28 is a three-quarter view of a cell insert, or sled, according to an eleventh embodiment of the invention, for use with a plant-propagating tray of the ninth or tenth embodiment;

[0099] FIG. 29 is a three-quarter view of the cell insert of FIG. 28 in position in a cell of the plant-propagating tray of FIGS. 22 to 26;

[0100] FIG. 30 is a three-quarter view of the cell insert of FIG. 28 in position in a cell of the plant-propagating tray of FIG. 27;

[0101] FIGS. 31 and 32 are vertical sections of the cell insert of FIG. 28, sectioned at 45 degrees to an edge of the tray, respectively without and with a stabilized medium in the cell insert;

[0102] FIGS. 33 and 34 are vertical sections of the cell insert of FIG. 28, sectioned parallel to an edge of the tray, respectively without and with a stabilized medium in the cell insert;

[0103] FIG. 35 is a three-quarter view from above of a four-cell portion of a plant-propagating tray according to a twelfth embodiment of the invention;

[0104] FIG. 36 is a top view of a portion of the plant-propagating tray shown in FIG. 35;

[0105] FIG. 37 is a first vertical section of a single cell of the plant-propagating tray shown in FIGS. 35 and 36, sectioned at 45 degrees to an edge of the tray; and

[0106] FIG. 38 is a second vertical section of the single cell of the plant-propagating tray shown in FIGS. 35 and 36, sectioned parallel to the edge of the tray;

DETAILED DESCRIPTION

Embodiment 1

[0107] FIG. 1 shows a portion of a plant tray, or plant-growing tray, 100 according to a first embodiment of the invention. The tray comprises a tray top 14 and a plurality of cells 10, each cell extending downwardly in use from the tray top and being shaped to contain a substrate for a plant. The tray comprises a rectangular array of cells and is formed as a single piece from injection-moulded plastic. FIG. 1 does not show all of the cells of the tray. It shows only a group of cells in a corner of the tray, which are repeated to form the rectangular array of cells in the complete tray, which may be a 6 by 10 array of 60 cells for example.

[0108] In the embodiment shown in FIG. 1, the plant-growing substrate is a suitable cylindrical stabilized medium 11, for example an Ellepot®. FIG. 1 illustrates one of the cells 10 containing a stabilized medium 11, as an example. However, in use, preferably each of the cells would contain a stabilized medium.

[0109] Each cell 10 comprises four projections or lugs 20 that extend inwardly, into the cell, from an edge of the tray top surrounding the cell. The projections are spaced symmetrically, at 90 degree intervals, around a circumference of the cell and are configured to abut and support an upper portion of a cylindrical stabilized medium within the cell. Beneath each projection, the cell comprises a pair of stabilized-medium-supporting ribs 22 which extend downwardly from the projection to a cell base 16. The cell base 16 comprises a raised central platform 18 within which a circular base hole 19 is defined. The hole allows access for a plunger for automated ejection of plants from the cells.

[0110] Each stabilized-medium-supporting rib 22 comprises a supporting edge configured to support a stabilized medium positioned in the cell, along the vertical length of the rib. The supporting edges may contact the stabilized medium but are advantageously arranged so that there is a small clearance between the ribs and the stabilized medium, so that the stabilized medium can be inserted into and removed from the cell. Between each pair of ribs, beneath each projection, an opening or aperture 23 allows ventilation to the stabilized medium, in use. The opening is optional; in alternative embodiments of the invention there may be fewer or no openings. In other words the cell may comprise a continuous surface between some or all of the pairs of ribs.

[0111] Adjacent projections, and the ribs extending downwardly from adjacent projections, are connected by cell side walls 12 which extend from the tray top to the cell base.

[0112] The support edges of the ribs 22 in a cell lie on a virtual cylindrical shape. A suitable stabilized medium 11 is preferably a corresponding parallel-sided cylindrical stabilized medium. A typical stabilized medium may be of 39 mm diameter and 90 or 120 mm height. In a suitable cell, the spacing between opposed projections may then be 40.3 mm and the spacing between opposed supporting ribs at the base of the cell may be 39.5 mm.

[0113] The stabilized medium 11 is thus supported by, or contacted by, the projections and by the support edges of the ribs so that it is supported and held in the middle of the cell. The side walls 12 connecting adjacent projections 20 and ribs 22 are set back slightly such that, when a stabilized medium 11 is received in the cell, gaps or voids are formed between the stabilized medium 11 and the side walls 12.

[0114] The gaps or voids advantageously extend downwardly into the cell sufficiently far, and the lateral dimensions of the gaps or voids are sufficient, to allow access by mechanical fingers of automated machinery for inserting and removing stabilized media into and from the cell. Similarly, the gaps or voids extend circumferentially around the stabilized medium in each cell sufficiently to allow access by mechanical fingers.

[0115] FIGS. 1 and 2 show how each cell 10 of the plant-growing tray 100 is associated with and surrounded by a catchment area 30 of the tray top 14 having a sloped surface. In use, water is supplied to encourage the growth of strong and healthy plants growing in the stabilized medium. The water is supplied from above using an overhead sprinkler system. A proportion of the water falls on each catchment area 30 and the sloped surface of each catchment area 30 is configured such that, in use, the water flows downhill towards the cell 10 associated with that catchment area 30. As each cell 10 is associated with a catchment area, water supplied to the tray is distributed evenly, or equally, between the cells. This reduces the risk, as with prior-art trays, of some of the cells being flooded with water while others are not supplied with enough water.

[0116] Each catchment area 30 surrounds its associated cell 10 and each catchment area 30 is associated with only one cell. Furthermore, the area of each catchment area 30 is the same, to ensure that equal amounts of water are directed toward each cell.

[0117] Each catchment area is bounded by perimeter ridges 25 (formed between the slopes of adjacent catchment areas) which separate it from adjacent catchment areas (or which bound the catchment area at the edge of the tray). In an alternative embodiment, perimeter ribs or walls may extend upwards along some or all of the perimeter ridges to further separate water falling on different catchment areas.

[0118] The tray top in each catchment area 30 is shaped to form four inclined valleys 24, each sloping radially inwards and downwards towards one of the projections or lugs 20 for supporting the stabilized medium.

[0119] Each catchment area is subdivided into four sections, each for directing water into one of the valleys. Each section is bounded by ridges 26 which are symmetrically arranged between adjacent valleys and extend radially between an edge of the cell and the perimeter ridge 25 bounding the catchment area. Therefore, water impinging on one of the four sections of each catchment area flows away from the ridges 25, 26 into the associated valley 24, and then towards the associated projection 20. The arrows of FIG. 2 lie along the valleys, and represent water flowing along the valleys towards the cell 10. The arrangement of four sections within each catchment area aims to ensure that water falling on the tray top is directed evenly, or equally, towards each of the four projections.

[0120] Each projection 20 comprises an upper surface 21, which slopes downwardly from a first end adjacent the tray top at the end of a valley to a second end which abuts the stabilized medium in the cell. The upper surface 21 is shaped to form a channel having an inlet at the first end and an outlet at the second end.

[0121] The tray 100 additionally comprises upstanding cell-edge ribs or walls 32 extending around each cell 10 on either side of each projection 20. As shown in FIG. 1, these ribs extend from each projection, around the cell edge to the ridge 26 which bounds the section of the catchment area associated with that projection.

[0122] In use, some of the water directed by the catchment area 30 may flow towards regions of the cell between adjacent projections. The cell-edge ribs 32 serve as a barrier to prevent at least some of this water from flowing directly into the cell. The water instead flows towards the upper surfaces 21 of the projections 20. As shown in FIG. 1, the cell-edge ribs 32 are curved away from the cell to form a lip extending over the catchment area. This shape encourages or promotes water to be directed to the projections 20.

[0123] It should be noted that the perimeter ridges 25 which bound the catchment areas all lie on a flat plane, and that all of the features of the shaped tray top lie (with the tray oriented for use) level with or below that plane. Thus, in the embodiment, the ridges 26 which separate the four sections of each catchment area lie in the same plane as the perimeter ridges, and the cell-edge ribs 32 are shaped to lie below or level with the plane. This may advantageously allow similar trays to be nested with each other efficiently, one on top of the other. This is very advantageous for storage and transport of the trays, and it is preferable if the shaping of the tray top to allow efficient watering of the plants in a tray is not to reduce the ability of the trays to nest with one another.

[0124] FIG. 3 is a vertical section of a cell, taken through two diametrically-opposed projections 20. The upper surface 21 of each projection 20 and the catchment area 30 forms a continuous surface. This allows water directed by the catchment area 30 towards the projections 20, to flow along the channel over the upper surface 21 of the projections 20 to the upper portion of stabilized medium 11. Water impinges upon the upper portion of the stabilized medium 11 and is absorbed.

[0125] The upper surface 21 of each of the projections 20 may also be shaped to form an upper reservoir 31, defined between the channel-shaped upper surface of the projection and the adjacent surface of the stabilized medium, as shown in FIG. 3. In use, water impinging on the stabilized medium 11 may not immediately be absorbed. In that case, water directed from the catchment area 30 may build up at the interface between the projection 20 and the stabilized medium 11. By providing an upper reservoir 31, this water can collect in the upper reservoir 31 to be more gradually absorbed by the stabilized medium 11, reducing the amount of water overflowing into the gaps between the cell wall 12 and the stabilized medium, on either side of the projection 20.

[0126] Each cell of the tray 100 is further configured such that a lower reservoir 36 is defined between each pair of adjacent projections 20, the stabilized-medium-supporting ribs 22 extending downwardly from those projections, the cell side walls 12 between the ribs, and the stabilized medium in the cell. As described above, the support edges of the ribs 22 are close to or in contact with the stabilized medium along a length of the stabilized medium 11.

[0127] One of the four lower reservoirs 36 is shown most clearly in FIGS. 2 and 4. The lower reservoir advantageously collects and contains, or retains, any water that flows into the gaps between the stabilized medium and the cell, including water that flows laterally off the sides of the upper surfaces of the projections, water which may flow over the cell-edge walls, and water which may fall directly into the lower reservoirs of the cell. Water flowing into the lower reservoir may impinge on, and so be absorbed by, the stabilized medium 11. Advantageously, this water may be absorbed by a lower portion of the stabilized medium than the upper portion supported by the projections 20. Any water flowing into the lower reservoir 36 may impinge on the stabilized medium along a substantial part of the length of the stabilized medium 11. This may advantageously reduce water wastage and ensure even watering of the stabilized medium along its length.

[0128] It should be noted that because of the clearances between the projections and the stabilized medium, and between the stabilizing ribs and the stabilized medium, any water entering the upper or lower reservoirs is not sealed into those reservoirs, but tends to leak out of the clearances. However, the rate of leakage is advantageously less than the rate of supply of water during watering, and so as water is supplied during watering, the water continuously flows from the catchment area into the upper and lower reservoirs, is continuously absorbed by the stabilized medium, and continuously leaks through the clearances at a lower rate. During watering, each reservoir thus retains a volume or head of water which is continuously absorbed by the stabilized medium. It may be noted that any leakage through the clearances also advantageously tends to flow down the side of the stabilized medium, giving a further opportunity for the stabilized medium to absorb the water. The only water that is wasted is any water that then flows away from the lower end of the stabilized medium without having been absorbed.

Embodiment 2

[0129] FIG. 5 shows a portion of a plant-growing tray 200 according to a second embodiment of the invention. The tray comprises a tray top 214 and a plurality of cells 210, each cell extending downwardly in use from the tray top and being shaped to contain a substrate for a plant. The tray comprises a rectangular array of cells and is formed as a single piece from injection-moulded plastic. Not all of the cells of the tray are shown in FIG. 5.

[0130] In the embodiment shown in FIG. 5, the substrate is a suitable stabilized medium 11, for example an Ellepot®.

[0131] Each cell 210 comprises four symmetrically-arranged projections or lugs 220 that extend inwardly, into the cell, from an edge of the tray top surrounding the cell. Beneath each projection, the cell comprises a pair of stabilized-medium-supporting ribs 222 which extend downwardly from the projection to a cell base 216, within which a central hole is defined to allow access for a plunger for automated ejection of plants from the cells.

[0132] Each stabilized-medium-supporting rib comprises a support edge configured to support a stabilized medium positioned in the cell, along the length of the rib. Each support edge is flanged to increase the area of the rib which supports the stabilized medium, to reduce pressure on the stabilized medium. Between each pair of ribs, beneath each projection, an opening 223 allows ventilation to the stabilized medium, in use. The aperture is optional; in alternative embodiments of the invention when there is no aperture, the cell may comprise a continuous surface between each pair of ribs. Such an embodiment is shown in section in FIG. 10.

[0133] Adjacent projections, and the ribs extending downwardly from adjacent projections, are connected by cell side walls which extend from the tray top to the cell base. The side walls are formed in two portions. An upper portion 212 is curved laterally or radially outwardly so that, when a stabilized medium 11 is received in the cell, a lower reservoir 236 is formed (as shown in FIG. 8) between the stabilized medium and the upper portion of the side wall. This is advantageously of larger volume than the lower reservoir in the first embodiment.

[0134] A lower portion 213 of each side wall is shaped to match and support or contact the outer surface of a cylindrical stabilized medium placed in the cell. The contact, or small clearance, between this lower portion of the side wall and the stabilized medium defines a lower boundary or edge to the lower reservoir.

[0135] The depth of the lower reservoir may be designed to allow sufficient access for the mechanical fingers of automated machinery for handling the stabilized medium, to reach a sufficient portion of the length of the stabilized medium for secure handling.

[0136] FIGS. 5 and 6 show how each of the cells 210 of the plant-growing tray 200 is associated with a catchment area 230 of the tray top 214 having a sloped surface. In use, water is supplied to the tray to encourage the growth of strong and healthy plants growing in the stabilized medium. The water is preferably supplied from above using an overhead sprinkler system. A proportion of the water will impinge on catchment areas 230. The sloped surface of each catchment area 230 is configured such that, in use, the impinging water is directed towards the cell 210 associated with that catchment area 230. As each cell 210 is associated with a catchment area, water supplied to the tray is distributed evenly between each of the cells, rather than pouring into a subset of cells, even if the tray is not precisely level, or if there is a prevailing wind. This reduces the risk of some of the cells being flooded with water while others are not supplied with enough water.

[0137] Each catchment area 230 is associated with only one cell. Each catchment area 230 comprises four equal sections spaced around the cell, each associated with one of the four projections 220 of the cell.

[0138] Each section of the catchment area 230 is bounded by a perimeter ridge 225 and is shaped to slope down to an inclined valley 224, Each valley extends radially inwards from a perimeter of the catchment area to one of the projections. A cell-edge rib, or wall, 232 extends away from each projection around the edge of the tray top surrounding each cell. Therefore, water impinging on each of the catchment areas of the tray top is directed towards their associated cells, and specifically to each of the projections 220. The arrows of FIG. 6 indicate the direction of water flowing along the valleys towards a cell.

[0139] Each projection 220 has an upper surface 221 which slopes downwardly towards the stabilized medium from a first, upper, end adjacent to, and level with, with the catchment area 230 to a second, lower, end adjacent to an upper portion of the stabilized medium 11. The upper surface 221 of the projection is shaped to form a channel having an inlet at the upper end and an outlet at the lower end. FIG. 7 is a section of one of the cells, taken through two opposing projections 220. The catchment area and the upper surface of each projection forms a continuous surface. This allows water directed by the catchment area towards the projection to flow over the upper surface of the projection to the upper portion of stabilized medium. The water impinges upon the upper portion of the stabilized medium and can be absorbed.

[0140] The upper surface of each projection is also shaped to form an upper reservoir 231, as shown in FIG. 7. A first portion of the upper surface leading away from the tray top is convex, to accelerate a flow of water from the tray top towards the stabilized medium. A second portion of the upper surface is concave, to slow down the flow of water as it approaches the stabilized medium, and to provide a suitable shape for the upper reservoir, defined between the upper surface of the projection and the outer surface of the stabilized medium, to retain an amount of water. In use, water impinging on the stabilized medium 11 may not immediately be absorbed. In that case, a volume of the water directed by the catchment area 230 may build up in the upper reservoir to eventually be absorbed by the stabilized medium 11, reducing any overflow of water over either side of the projection 220.

[0141] It may be noted that the edges of the channel formed as the upper surface of each projection may be continuous with, or formed as extensions of, the cell-edge ribs, or walls, 232.

[0142] The cell comprises a lower reservoir 236 between each pair of adjacent projections, as described above. The lower reservoirs are shown most clearly in FIGS. 6 and 8. Each lower reservoir advantageously contains or retains any water that flows into the gaps between the stabilized medium and the cell, either flowing over edges of the projections or out of the upper reservoir, or directly over the cell-edge wall, or falling directly into the lower reservoir. This water held in the lower reservoir may then impinge on, and so be absorbed by, the stabilized medium 211 lower down than the upper portion of the stabilized medium supported by the projections 220. This may advantageously reduce water wastage.

[0143] Furthermore, the depth of the lower reservoir 236 with respect to the stabilized medium 11 may affect in which portion of the stabilized medium 11 water is predominantly absorbed. In the embodiment shown in FIG. 8, the lower reservoir 236 extends approximately three-quarters of the depth of the cell such the water will be absorbed in the stabilized medium 11 in a lower portion, or near its base. In other embodiments it may be preferred for water to be absorbed from the lower reservoir at a different position, higher or lower in the stabilized medium. A deeper lower reservoir may also advantageously allow the mechanical fingers of automated machinery for handling the stabilized medium to reach a greater portion of the length of the stabilized medium.

Embodiment 3

[0144] FIG. 9 shows a third embodiment, in which a cell 310 of a plant-propagating tray has a differently-shaped side wall in which the lower portion 313 of the side wall that supports or contacts the stabilizing medium 11, and which delimits the lower edge of the lower reservoir 336, extends about half way up the stabilizing medium. Therefore, the lower reservoir 336 only extends about half way down the cell and water is absorbed into the stabilizing medium 11 from the lower reservoir 336 at a middle portion of, or about half way up, the stabilized medium.

Embodiment 4

[0145] FIG. 10 shows a fourth embodiment of a single cell 410 of a plant-propagating tray. This embodiment is similar to that shown in FIGS. 5 to 8. However, in the fourth embodiment, there is no aperture defined below each projection. Instead, a cell wall 440 is formed between the stabilized-medium-supporting ribs beneath each projection 412, which supports the stabilized medium. This may be desirable for plants that do not require a high degree of ventilation or aeration, or where the stabilized medium requires additional support.

Embodiment 5

[0146] FIGS. 11 and 12 illustrate a portion of a plant tray according to a fifth embodiment of the invention. FIG. 11 shows four adjacent cells of the tray. Features of the tray common to those of the first embodiment, illustrated in FIGS. 1 to 4, are identified with the same reference numerals.

[0147] Each cell 10 comprises four evenly-spaced projections 20 around its rim, for supporting an upper portion of a stabilized medium such as an Ellepot 11. The tray top comprises inclined catchment areas 30, which each comprise four catchment-area portions or sections surrounding each cell. Each catchment area comprises surfaces which slope towards valleys 24, which in turn slope downwardly towards upper surfaces 21 of the projections 20.

[0148] Between each adjacent pair of projections, a cell wall 12 is set back to form a gap between the cell wall and a stabilized medium supported in the cell. A cell-edge rib 32 extends along an upper edge of each cell wall, and alongside the upper surface 21 of each adjacent projection.

[0149] The tray further comprises a peripheral wall 250 surrounding each catchment area, and dividing each catchment area from adjacent catchment areas. The peripheral wall also extends around outer edges of the tray. The peripheral wall helps to ensure that during watering, water falling on one catchment area tends to be retained in that catchment area and does not splash or flow into adjacent catchment areas, even if the tray is not exactly level or if there is a prevailing wind.

Embodiment 6

[0150] FIG. 13 illustrates a portion of a plant tray according to a sixth embodiment of the invention. FIG. 13 shows four adjacent cells of the tray. Features of the tray common to those of the first and fifth embodiments are identified with the same reference numerals.

[0151] Each cell 10 comprises four projections 20 around its rim, for supporting an upper portion of a stabilized medium such as an Ellepot 11. The tray top comprises inclined catchment areas 30, which each comprise four catchment-area portions or sections surrounding a cell. Each catchment area comprises surfaces which slope towards valleys 24 which in turn slope downwardly towards upper surfaces 21 of the projections 20. The upper surfaces of the projections are shaped to form upper reservoirs for retaining water in contact with an upper portion of the stabilized medium.

[0152] Between each adjacent pair of projections, a cell wall 12 is set back, to form a gap between the cell wall and a stabilized medium supported in the cell. In this embodiment, the cell wall is set back from the stabilized medium so that a central part of the cell wall lies along an outer edge of the catchment area.

[0153] As in the fifth embodiment, the tray comprises a peripheral wall 250 surrounding each catchment area, and dividing each catchment area from adjacent catchment areas. The peripheral wall in this embodiment is about the same height as in the fifth embodiment, at around 3 mm. In general, the peripheral wall height may be between about 1 mm and 10 mm, or between 2 mm and 5 mm or 7 mm.

[0154] The tray further comprises a ventilation hole 252 formed through the tray top at each corner of each catchment area. Thus, a ventilation hole is formed at each point at which four adjacent catchment areas meet. The peripheral wall of each catchment area extends along an edge of each adjacent ventilation hole, so that each ventilation hole is surrounded by peripheral walls. In this way, the peripheral walls prevent or reduce the rate at which water may splash or flow through the ventilation holes during watering. The ventilation holes advantageously provide additional ventilation to the space below the tray top and between the cells, preferably without significantly increasing water wastage. During watering, some water may pass through the ventilation holes and be wasted, but advantageously this may only be water which falls directly into the ventilation holes. Any water which falls on the catchment areas or into the cells well flow towards the Ellepot for absorption. Thus, the area of the ventilation holes may be limited to a predetermined area of the tray top, depending on the type of plants to be grown in the tray and the growing conditions.

Embodiment 7

[0155] FIGS. 14 to 20 illustrate a plant-growing tray according to a seventh embodiment of the invention. Features of the tray common to those of earlier embodiments are identified with the same reference numerals.

[0156] FIGS. 14 and 15 are three-quarter views, from different angles, of a group of four adjacent cells which may be repeated to form a tray of any desired size. One cell is shown holding a stabilized medium 11 for growing a plant. The cells are arranged in a square array, and each cell 10 comprises four inwardly-facing projections 20 around its rim, one at each corner.

[0157] In use, the projections in each cell support an upper portion of a stabilized medium. Additional support for the stabilized medium is provided above the projections by a pair of cell-edge rims, or walls, 32 which extend upwardly at each side of each projection 20, and below the projections by a pair of stabilized-medium-supporting ribs 222 which extend downwardly from each side of each projection to a cell base. Between each pair of stabilized-medium-supporting ribs 222, below each projection 20, an aperture provides ventilation to the stabilized medium. At its base, the cell tapers inwards to encircle and support the base of the stabilized medium.

[0158] For each cell, the tray top comprises a catchment area in the form of four separate catchment-area portions or sections 30. Each catchment-area portion extends inwardly from a corner of the square tray-top section surrounding each cell, and slopes downwardly towards an upper surface 21 of a respective projection 20.

[0159] Each catchment-area portion is bounded on each side by the upstanding cell-edge ribs, or walls, 32 which extend from the tray top rim 25 to the projection 20. The cell-edge ribs and the upper surfaces of the projections define upper reservoirs for retaining water in contact with an upper portion of the stabilized medium. In this embodiment, the upper reservoirs are shaped to improve absorption of water by the stabilized medium. An upper part of each catchment-area portion is shaped similarly to the catchment area in FIG. 5, to transport water falling on the catchment area towards the stabilized medium as illustrated by the arrows in FIG. 16, and to form an upper portion of the upper reservoir. However, the downward slope of each catchment-area portion increases at its lower end, to form a substantially vertical, downwardly-extending surface ending at the projection 20. This can be seen in the sectional views of the cell of FIGS. 17 and 18. This vertical surface is bounded at its sides by the cell-edge ribs 32, which form support surfaces which abut, or are closely spaced from, the cylindrical surface of the stabilized medium.

[0160] The vertical, downwardly-extending surface of each catchment-area portion extends each upper reservoir downwards, forming a high-aspect-ratio lower portion 31′ of each upper reservoir 31. The lower portion can for example extend downwardly as much as 10% or 20% of the total height of the stabilized medium, it can extend around as much as 5% to 10% of the circumference of the stabilized medium, and the vertical surface of the catchment area is relatively closely spaced, in a radial direction, from the cylindrical surface of the stabilized medium, spaced only by the height of the cell-edge ribs flanking it on each side. The volume of each lower portion 31′ of the upper reservoir is therefore relatively small, although it contacts a relatively large area of the surface of the stabilized medium.

[0161] These dimensions and shape of the upper reservoir have the following beneficial effects.

[0162] When water falls on the catchment areas and flows towards the stabilized medium, the small volume of the lower portion 31′ of each upper reservoir is quickly filled. Further water then starts to fill the larger-volume upper portion of each upper reservoir. At the same time, because the area of the lower portion 31′ in contact with the stabilized medium is large, water is absorbed rapidly from the lower portion 31′ into the stabilized medium. As water is absorbed, the lower portion 31′ is continually refilled by water flowing from the upper portion of the upper reservoir, until the supply of watering water ceases.

[0163] As has been described earlier, because of the need for the stabilized medium to be removable from the cell, and because there is some variation in the dimensions of different stabilized media, a small clearance is needed between the stabilized medium 11 and the supporting projections 20 and the cell-edge ribs 32. During watering, water therefore leaks continuously from the upper reservoir at a rate dependent on the size of the clearance. By increasing the area of the upper reservoir in contact with the stabilized medium, and so increasing the rate of absorption of water by the stabilized medium, the lower portion 31′ of the upper reservoir reduces the time required for the stabilized medium to absorb a desired volume of water. This reduces watering time, and therefore the time during which water leaks from the upper reservoir through the clearance, reducing the amount of water potentially wasted.

[0164] The lower portion 31′ of each upper reservoir also increases the surface area of the stabilized medium through which water is absorbed, and so improves the distribution of water in the stabilized medium.

[0165] As shown in FIGS. 14 and 15, and in section in FIGS. 19 and 20, a cell wall 12 extends downwardly from the tray-top rim 25 between each adjacent pair of catchment-area portions 30. The cell wall 12 is spaced from the stabilized medium to form a lower reservoir 36, in the same way as in embodiments described above. During watering, water that falls directly into the lower reservoir, or which may overflow into the lower reservoir from the upper reservoirs or from the catchment area, collects in the lower reservoir for absorption by the stabilized medium.

[0166] In this embodiment, the cell wall 12 which bounds the lower reservoir is shaped so that the lower reservoir 36 comprises an upper portion and a lower portion 36′. As in other embodiments, the upper portion is wide enough and deep enough (extending about halfway down the length of the stabilized medium) to receive mechanical fingers and allow automated insertion and removal of the stabilized medium from the tray. In the lower portion 36′ the cell wall is closer to the stabilized medium, and extends further down the stabilized medium. Between the upper and lower portions the cell wall is formed with a step, where it moves closer to the stabilized medium. As shown in the sectional views of FIGS. 19 and 20, in this embodiment the lower portion 36′ of the lower reservoir extends substantially to the base of the stabilized medium, where the bottom end of the cell wall tapers inwards to contact and support the base of the stabilized medium and to close the bottom end of the lower portion 36′ of the lower reservoir.

[0167] The lower portion 36′ of the lower reservoir provides the same advantages as described above for the lower portion 31′ of the upper reservoir. The lower portion 36′ of the lower reservoir enables a small volume of water to contact a large area of the stabilized medium, for rapid water absorption into a lower part of the stabilized medium. The lower portion 36′ can be quickly refilled by water which has collected in the larger-volume upper portion of the lower reservoir. This reduces watering time, reduces water wastage, and increases the distribution of water to different parts of the stabilized medium.

[0168] In this embodiment, it should be noted that the supporting surfaces for the stabilized medium, namely the projections 20, the cell-edge ribs 32, and the stabilized-medium-supporting ribs 222, have advantageously optimized surfaces for contacting or supporting the stabilized medium. In particular, the cell-edge ribs and the stabilized-medium-supporting ribs are outwardly flanged at their edges which contact the stabilized medium. This decreases pressure at the points of contact between the cell and the stabilized medium, reducing the risk of damaging or distorting the stabilized medium and improving mechanization by reducing frictional forces between the stabilized medium and the cell during insertion and removal of the stabilized medium.

Embodiment 8

[0169] FIG. 21 illustrates a four-cell portion of a plant-growing tray according to an eighth embodiment of the invention. The cells in this embodiment have similar features to those described above for the seventh embodiment, but the ratio of cell width to cell height is larger than in the seventh embodiment. This allows shorter, or wider, stabilized media to be accommodated while achieving the same advantages as in the seventh embodiment.

Embodiment 9

[0170] FIGS. 22 to 26 illustrate a plant-growing tray according to a ninth embodiment of the invention. Features of the tray common to those of earlier embodiments are identified with the same reference numerals.

[0171] In this embodiment, cells are arranged in square array and bounded at the tray top by a peripheral wall 250 surrounding each cell. A tray-top catchment area 30 around each cell is bounded at its outer edge by the peripheral wall and at its inner edge by cell-edge rims 32, and slopes downwardly at each corner of the cell to an upper surface 21 of a stabilized-medium-supporting projection 20. This forms four upper reservoirs 31 spaced around a stabilized medium in the cell. Between each adjacent pair of upper reservoirs, a cell wall 12 extends downwardly from the cell-edge rim to define a lower reservoir 36 for providing water to a lower portion of the stabilized medium.

[0172] During watering, water falling on the catchment area flows into the upper reservoirs, and water falling directly into the lower reservoirs, or overflowing from the catchment area or from the upper reservoirs, flows into the lower reservoirs.

[0173] In certain applications, a stabilized medium in a cell may benefit from ventilation. In the cell of the present embodiment, ventilating apertures are formed below each projection 20, between pairs of stabilized-medium-supporting ribs 222 which extend downwardly from each side of each projection. However to increase ventilation, additional apertures 260 are provided in the cell walls 12. These apertures open into the lower reservoirs and so there is a risk that, during watering, water may flow out of the apertures and be wasted. To minimize this risk, aperture-surrounding walls 262 extend from edges of the apertures inwardly into the lower reservoirs. As shown in the sectional views in FIGS. 25 and 26, each wall is tapered in height, being highest at the upper end of the aperture. In addition, a tapered flange extends upwardly from the aperture-surrounding wall at an uppermost edge of the aperture. The flange and the wall divide and deflect water that flows or falls into the lower reservoir away from the aperture, reducing water wastage. The taper of the wall also provides a suitable draft angle to enable the cell to be moulded from plastic.

[0174] The flange also serves to guide the stabilized medium away from the aperture-surrounding wall as the stabilized medium is inserted into the cell, to avoid it snagging on the aperture-surrounding wall.

[0175] As can be seen in the section of FIG. 26, with a stabilized medium in the cell, the aperture-surrounding wall 262 does not contact the stabilized medium. Therefore, air can flow freely from the lower reservoir through the aperture, providing ventilation to the entire surface of the stabilized medium which faces the lower reservoir.

[0176] If during watering the water level in the lower reservoir rises to the level of the aperture, water will flow out of the aperture and be wasted. Therefore, the aperture is advantageously positioned sufficiently high on the side wall of the lower reservoir to allow the lower reservoir to contain enough water to provide a desired volume of water to the growing medium. However, it may still be desirable to control the rate of water supply during watering so that the rate of water absorption from the lower reservoir into the stabilized medium is sufficient to avoid water loss through the aperture.

Embodiment 10

[0177] FIG. 27 illustrates a plant-growing tray according to a tenth embodiment of the invention. This embodiment has the same structure as that of the ninth embodiment, illustrated in FIGS. 22 to 26, except that each cell is deeper. The cells can therefore support longer stabilized media (or stabilized media of higher aspect ratio) than the cells of the ninth embodiment.

Embodiment 11

[0178] Differently sized stabilized media are used for growing and propagating different plants.

[0179] The plant trays of the ninth and tenth embodiments have similar features and accommodate differently-sized stabilized media, but a grower would need to procure sets of such trays in order to grow many plants in differently-sized stabilized media. To solve this problem a more flexible system is provided by a further embodiment of the invention, namely the cell insert, or sled, illustrated in FIGS. 28 to 34. The cell insert is for use with plant-growing trays according to the ninth and tenth embodiments of the invention, and enables those trays to be used with longer stabilized media than the trays would normally be able to accommodate.

[0180] In the drawings, features of the cell insert, or sled, common to those of earlier embodiments are identified with the same reference numerals.

[0181] As shown in FIG. 28, the cell insert 500 is a single cell for receiving a stabilized medium, surrounded by a single-cell tray top 502 incorporating a catchment area for directing water to the stabilized medium. The cell insert can be inserted into a cell of the tray of the ninth embodiment, as shown in FIG. 29, or the tenth embodiment, as shown in FIG. 30. The external surface of the cell insert is shaped to slide securely into cells of either of these trays, and in each case to enable the tray to be used with longer stabilized media without the grower needing to purchase and store entire trays of the larger depth.

[0182] Cell inserts can be inserted into all of the cells of the trays of the ninth and tenth embodiments and, when this is done, the single-cell tray tops 502 of the inserts align with each other to form a full tray top having the same shape and features as that of the tray into which the cell inserts are inserted. The single-cell tray tops 502 are generally square in shape, having the same dimensions as the cells of the tray in which they are held, and they have rounded corners 504 so that when four cell inserts are placed in adjacent cells of a tray, a ventilation hole is formed between them.

[0183] The remaining features of the cell insert are the same as the cells of the trays of the ninth and tenth embodiments, forming upper and lower reservoirs for directing watering water to the stabilized medium. However because of the increased depth of the cell, the lower reservoirs are deeper than in the ninth and tenth embodiments and so two apertures 264, 268 are formed, one above the other, through the cell wall to increase ventilation in the lower reservoir. The apertures are surrounded by tapered walls 266, 268 in the same way as the apertures in the cell walls of the ninth and tenth embodiments. These can be seen in section in FIGS. 33 and 34.

[0184] In the same way as for the ninth embodiment described above, the lower apertures are positioned sufficiently high up the side walls of the lower reservoirs so that the reservoirs contain a desired volume of water to be absorbed by the growing medium, without water loss through the apertures.

Embodiment 12

[0185] FIGS. 35 to 38 illustrate a four-cell portion of a plant-propagating tray according to a twelfth embodiment of the invention. The Figures illustrate four adjacent cells of the tray. Features of the tray common to those of earlier embodiments are identified with the same reference numerals.

[0186] Each cell 10 is encircled by a sloping catchment area 30. The catchment area slopes towards four valleys 24, which direct water towards a stabilized medium or Ellepot 11 supported in the cell.

[0187] The cell is a circular cell in which the cell wall tapers inwardly towards its base. The cell comprises four cell-wall portions 256 positioned between apertures 258 which extend downwardly from a point beneath an end of each valley 24. An edge 254 of the catchment area curves downwardly from the catchment area to the cell wall to form an upper reservoir, in use, encircling the Ellepot. The curvature of the edge 254 varies around the circumference of the Ellepot so that the upper reservoir is deepest at the ends of the valleys 24. In an alternative embodiment, the apertures 258 may be omitted, so that the cell is formed as a closed cell.

[0188] FIG. 36 illustrates with arrows the direction of water flow during watering. FIGS. 37 and 38 illustrate in section the formation of the upper reservoir encircling the Ellepot, and the curved cell edge 254 at the end of each valley 24. The outer periphery of the catchment area is square and FIGS. 37 and 38 are, respectively, sections taken diagonally and laterally across the catchment area and the cell. In both sections the slope angle of the catchment area, in a radial direction, is 30°, but because the distance between a corner of the periphery of the catchment area and the cell, shown in FIG. 16, is greater than the distance between an edge of the periphery of the catchment area and the cell, shown in FIG. 38, the catchment area creates a lower irrigation point, or a deeper upper reservoir, at the portions of the cell aligned with the corners of the periphery of the catchment area.

[0189] The plant tray in the twelfth embodiment may advantageously enable effective watering of a stabilized medium held in each cell, with significantly less water wastage than in prior-art trays, but the lack of spacing between the cell walls and the stabilized medium may disadvantageously prevent access for the mechanical fingers of a mechanized handling apparatus. Manual handling of plants in the tray may therefore be required.