CA1110070A - Soil supports for plant containers - Google Patents

Abstract

SOIL SUPPORTS FOR PLANT CONTAINERS
Abstract of the Disclosure Method of making a soil support for a plant con-tainer having a water reservoir beneath the support. The support is mate by providing a fabric of water-absorbent fabric which is carried by support members. To hold the fabric in place, at least one fabric region is deformed and held in deformed state by a support member. In a preferred arrangement at least two spaced regions are deformed so as to stretch and tension the fabric between these regions and the regions are retained in deformed state by the support members and maintain the tension. In practice, support members are made by plastics injection moulding. The injection pressure deforms fabric extending across mould cavities and the plastics hardens to retain the deformed shape.

Description

~ 70 This invention relates to soil supports for plant containers and to methods of their manufacture.
Plant containers are known which have a reservoir for water disposed above which is a soil support for support-ing material such as particulate or humus materials whichmay be used for holding roots ~f plants. Materials for this purpose will be referred to throughout this specification as "soil".
Suggestions have been made for the provision within or upon said supports of a water absorbent fabric which con-tacts the soil and has a portion which hangs into water con-tained within the reservoir for the purpose of raising the water from the reservoir and into the soil by the absorbent action of the fabric. With this arrangement> the need for constant rewatering of plants is avoided and with the use of a filled reservoir, a plant requires little or no attention for long periods of time.
To assist in the transfer of water to the soil, supports have been described which have openings through

2~ them so that parts of the fabric extending across these openings are in contact with and support the soil while facing downwardly into the reservoirs of their containers.
With this arrangement, moisture is transferred to the fabric also by evaporation from the surface of the water in its reservoir and condensation upon the underside of the fabric.
Clearly for water transfer to be fully effective by the evaporation and condensation process, then the openings in the supports need to be as large as possible together with the requirement that the fabric extending across the openings is sufficiently strong to support the weight of the soil and - 2 - ~

~ 7 0 preferably will not be caused to sag in the regions of the openings under this weight.
~ ccordingly, one aspect of the present invention provides a method of making a soil support for a plant con-tainer in which the support has a plurality of fabricsupport members defining openings between them and a layer of substantially inextensible, water absorbent fabric extending across the openings in planar manner, the method comprising causing deformation of the fabric out of its plane in at least one region of the fabric and securing the deformed region to a support member to retain said region in its deformed state.
By the use of the above method; the fabric is secured in at least one region, that is, the deformed region.
This prevents relative movement of fabric and the support member to which the deformed region is secured.
The method of the invention is preferably performed by holding the layer of fabric within an open injection mould, closing the mould to hold the fabric facing across the flow path of thermoplastics material to be injected into a mould cavity for moulding the support member, and injecting the thermoplastics material into the mould to form the support member. The pressure of the material being injected forces the region of fabric which lies adjacent the cavity, into the cavity so as to deform said region, the thermoplastics material, after cooling, retaining the region in its deformed condition.
By the injection method of making support members, some of the injected material may flow through interstices in the fabric so that parts of the region are embedded in ~11CM~7 0 the support member.
In a preferred method, deformation of the fabric i8 caused in at least two spaced-apart regions by the application of pressure to the fabric to place the fabric in tension between the two regions. The two regions are secured to two spaced-apart support members, one region to each member, and the members are retained spaced-apart to hold the fabric in tension.
Holding the fabric between two deformed regions in tension resists any tendency for the fabric to sag under the weight of soil even when the openings defined between the support members are of substantial size, e.g. of the order of around 15 mm square or larger, such as a rectangular shape w~th proportions of 15 mm and 25 mm for the minimum and maximum dimensions.
In an alternative way of performing the inventive method, the fabric is deformed into contact with and held against non-planar surface parts of support members. Welding techniques or adhesives may be used to hold the deformed regions of fabric in place.
Secondary support members may also be used to sandwich the deformed regions of fabric against the first mentioned support members and either welding techni~ues or mechanical locking means may be used to retain support members on f~bric in an assembly.
The invention also includes a soil support with a substantially inextensible water absorbent fabric extending in planar manner across openings between support members, and with at least one region of ~abric being held in a con-dition deformed from the plane of the fabric by a supportmember.

Embodiments of the invention will now be des-cribed, by way of example, with reference to the accompanying drawings, in which:-FIGURE 1 is a cross-sectional side view of a plant container having a soil support according to a first embodiment;
FIGURE 2 is a plan view of the soil support of Figure l;
FIGURE 3 is an underside plan view of the soil support of Figure l;
FIGU~E 4 is an isometric v~ew of a detail of the soil support of Figure 1 and on a larger scale;
FIGURE 5 is a cross-sectional view of the sQil support taken along line 'V-V' in Figure 3 and on a larger scale than Figure 3;
FIGURE 6 is a view similar to Figure 5 ~ut taken along line 'VI-VI' in Figure 3;
FIGURE 7 is a cross-sectional view of one side region of the soil support of Figure 1 and on a greatly enlarged scale;
FIGURE 8 is a diagrammatic side elevational view, in cross-section, of part of injection moulding machine showing a first stage in the manufacture of the soil support of the first embodiment;
FIGURES 9 and 10 are lateral cross-sectional scrap views, on the came scale as Figure 7 showing further stages in the manufacture of the support;

lll~Q7 ~

FIGURE 11 is a lateral cross-sectional view of part of a soil support according to a second embodiment and on enlarged scale;
FIGURE 12 is a plan view of the support of Figure 11 and on a smaller scale;
FIGURE 13 is an underside plan view of the support of the second embodiment;
FIGURES 14 and 15 are lateral cross-sectional views on the scale of Figure 11 showing two different stages in the manufacture of the support of the second embodiment;
FIGURE 16 is an underside plan view of a soil support according to a third embodiment;
FIGURE 17 is a cross-sectional view along line 'XVII-XVII' in Figure 16 of part of the oil support and on a larger scale;
~IGURE 18 is a lateral cross-sectional view of parts of the elements of the support of the third embodiment and on the same scale as Figure 17, showing one stage in its manufacture; and FI~URE 19 is a view similar to Figure 17 of a fourth embodiment.
In a first embodiment, as shown in Figure 1, a soil support 1 is held between sides 2 of a plant container for supporting plant-containing soil 3 from a lower water reservoir 4.
The soil support, as shown in Figure 2, is of rectangular plan to fit ~etween the container sides 2. The support comprises a layer of substantially inextensible ~ N~70 water-absorbent woven fabric 5 made from nylon filament.
This layer is held generally in substantially planar con-figur2tion by a fabric support structure comprising injection moulded support members 6 which are in the form of bars and 5 extend upwardly from the layer and lie both longitudinally and laterally of the support. The longitudinal bars merge with the lateral bars at crossing positions to form rectangular cells or openings 7 between them, the openings having maximum and minimum dimensions of 25 mm and 15 mm (approximately 1 inch x 0.6 inches). As shown in Figure 4, the bars which have a height of about 4 to 6 mm (0.25 inches) have tapered sides to allow for their removal from a mould.
Along each longitudinal edge o~ the layer of fabric, the support is in the form of a narrow planar frame 8 of plastic which overlies and extends beyond the edges of the fabric (Figures 5 and 6~ to terminate in a thicker marginal bead 9 which extends in continuous fashion around the upper side of the support.
The layer of fabric extends outwardly from one end of the rectangular support to provide a flexible extension 10 having a thermoplastics moulded weight 11 on one side of it.
When the support is fitted into the container, the extension is folded downwards at the frame 8 so as to hang into the water reservoir whereby water is raised into the support and from there into the soil by capillary action in the fabric.
The weight 11 ensures that the extension 10 does extend into the water.
On the ~lnderside of the support (Figure 3), certain of the longitudinal support members project below the plane of the fabric layer (see also Figures 5, 6 and 7) to provide l~lQQ70 lower portions 12 of the support members. The portions 12 extend from the bead 9 at the two ends of the support and are interrupted in a central region 13 of the support.
The bead 9 projects downwardly below the plane of the fabric layer and is substantially continuous on the underside of the support except for two regions at the end of the support having the extension 10 in which two narrow gaps 14 are formed in the bead ad;acent the longitudinal edges of the fabric. As will be descr~bed, because of the manner in which the support is made, water being fed by capillary action up the extension 10 cannot pass along the fabric extending through the bead 9, nor is it possible for water to pass along parts of the fabric extending through the supports 6 when the supports project below the plane of the fabric to form the lower portions 12. Hence, the movement of water in the fabric layer is controlled so as to flow from extension 10 only through the gaps 14 in order to reach the fabric regions held within the rectangular confines of the support. The water may only flow from gaps 14 along the narrow edges of fabric to the central region 13 of the support when it is possible for it to flow laterally inwardly across the fabric between the lower portions 12 and then longitudinally of the fabric between side-by-side lower portions 12 and towards the ends of the support. The support with its arrangement of support members 5, frame 9, and lower portions 12 of the support members is constructed and operates to control water flow in the manner described in Patent Application No. 344,467, entitled "Water Distributing Soil Support For Plant Containers", Applicant Manufacture Provencale de Matieres Plastiques SA, filed August 27, 1979.

~ 7 ~

In addition to the lower portions 12, a plurality of spaced boss-shaped projections 15 extend downwardly beneath the plane of the fabric layer from a centrally dis-posed laterally extending support member 6a and these pro-S jections lie in the central region 13 of the support.
As may be seen from Figure 7, although the lower portions 12 of the support members extend below the plane of the fabric layer, the layer does not extend in planar fashion through the mass of thermoplastics material which forms the support members 6 but is deformed downwardly in the regions 16 within each lower portion 12, The support members 6 hold the deformed regions in their deformed state so as to pro-vide an extremely effective securing arrangement of the fabric layer so as to prevent its slippage under weight of soil in the container, The retention of the deformed regions 16 in position is also assisted by the fact that thermo-plastics material of the support members extends through and fills interstices in the fabric layer so as to lock each thread of fabric in the deformed regions, As will be des-cribed below, the method of ma~ing the support causes atensile force to be applied in the layer between adjacent support members whereby the layer is held taut between its deformed regions, Although not shown in the drawings, the fabric layer is alxo deformed downwardly within the boss-shaped projections 15, The soil support is formed as one of a successionof similarly constructed and shaped supports by a process using an injection moulding machine as shown in Figures 8, 9 and 10. As shown in Figure 8, an indefinite length 17 of fabric is fed with intermittent motion between mould halves ~ 7 ~

18 and 19. The mould half 18 has interconnected mould cavities 20 for moulding the support members 6 and mould half 19 has cavities 21 for moulding the lower portions 12 of the support members 6. The cavities 21 are aligned with longitudinal cavities 20 and are spaced laterally of the path of movement of the fabric layer~ As shown in Figure ~, one end of the mould half 18 is formed with a cavity 22 for moulding the weight 11, the cavity 22 being connected with the cavities 20 by a runner 23.
In use, with the moulding machine open as shown in Figure 8, the length 17 of fabric is moved a controlled dis-tance through the machine to remove from the mould a soil support 1 which has just been made to feed it forward for a severing operation to remove it from the length 17. A
succeeding part of the length 17 for making the fabric layer 5 i8 then disposed in position between the mould halvPs.
Upon closing the mould (Figure 9), the length 17 lying between the mould halves is in planar condition and separates cavities 20 from cavities 21 with which they are aligned. The thermoplastics material for moulding the frame 8, bead 9 and support members 6 is then injected through a sprue 24 (Figure ~) and flows along the cavities 20 to extreme cavity areas 25 (Figure 9) for moulding the planar frame 8 while passing partly through interstices of the fabric facing onto these cavities. The thermoplastics material is not free to flow directly into cavities 21 because the length 17 of fabric extends across the flow path.
Hence, the force created by the forward movement of the injected material under the injection pressure, stretches

3~ the regions 1~ of the fabric in front of it, out of the ~ 7~

plane of the fabric so that these regions become deformed.
This stretching and deformation procedure places a tensile force in a transverse direction in tne fabric lying between the cavities 21; the support members together with their lower portions 12, hold the deformed regions in their de-formed conditions after cooling of the thermoplastic - material. As the support members and portions 12 cannot move relative to one another in the total structure, the fabric between adjacent deformed regions 16 is maintained in tension.
In the finished construction as shown in Figure 10, fabric in parts of deformed regions 16 may be stretched to contact mould surfaces of the cavities 2i so as to be visible at surfaces of the lower portions 12 of the support lS members in the finished structure. In other instances, thermoplastics m~terial passes through interstices in the deformed regions of the fabric so that parts of at least some deformed regions are completely embedded in the lower portions 12 of the members 6.
After the severing of each soil support from the length 17 of fabric, the runner material 26 (Figure 2) connecting the weight 11 with the moulded structure is easily broken manually to permit the flexible extension 10 o~ the support to be folded down together with its weight to assume 2~ its working position shown in Figure 1.
In the above embodiment, the support structure is iniertion moulded from a material having an injection mould-ing temperature below a temperature at which the material of the fabric layer is degradable by melting or softening. In this embodiment, the fabric layer is nylon ~Jhile the support 111~07 structure is made from polystyrene.
In use of the soil support in the plant container of Figure 1, à plant has its roots embedded in the soil 3 which i8 carried by the soil support. Most of the weight of the soil is taken into the fabric layer 5 in the regions of the openings 7. The layer ~ is prevented from sagging by the lower portions 12 of the support members stopping slippage of the deformed regions 16 of fabric and maintaining the tension in the fabric between the support members. Thus, l~ a firm and substantially stable support is provided for the soil.
In addition, because the deformed regions 16 of the fabric layer are embedded in the thermoplastics material which blocks t-he interstices in these regions, water may flow only along pathways defined between the lower portions 12 of the support members and is controlled in the manner described above in this embodiment.
In the above construction, the support members 6 and 6a extend upwardly from the fabric layer 5 and provide discrete cells or openings 7 and thus separate the soil in one cell from that in ad;acent cells or openings. This soil separation reduces the tendency of the soil at the lower portions thereof from forming a single hardened mass which could resist the upward percolation of water from the fabric layer to the plant roots. Thus> the method of forming the soil support described in this embodiment allows for the provision of the upwardly standing support members while pro-viding a means for holding the fabric layer securely in place.
In a second embodiment sho~m in Figures 11, 12 and 13, a soil support comprises a rigid rectangular fabric support structure 29 formed from laterally and longitudinally extending support members which extend upwardly from a layer 30 of fabric to form cells 31. The lateral edges of the support member structure are joined to planar frames 32, similar to the frames 8 in the first embodiment.
The longitudinal support members 33 extend in side-by-side parallel relationship from the two ends of the structure and are joined to a marginal continuous bead 34.
Each support member 33 is formed on its underside with a non-planar surface in that the member is of inverted U-shape in lateral cross-section in operating position (Figure 11 shows part of the structure?. The non-planar surface defines the sides of a groove 35 extending longitudinally in each support member 33. The bead 34 is of similarly shaped cross-section with its groove being interconnected with that of each support member 33. Each support member 33 is longi-tudinally aligned with another member 33 extending from the other end of the structure. Aligned support members are joined together by shallower, ungrooved support members 36.
The lateral support members 37, of shape and size similar to members 36, join side-by-side members 33 and side-by-side members 36 to complete the cell structure.
The layer 30 of fabric which is of the same structure as that of the first em~odiment extends longi-tudinally beneath the structure 29 and has a flexible extension 38 with a moulded weight 3~. The layer 30 has regions 40 (Figure 13~ which are deformed upwardly into the grooves 35 and the thermoplastic material of the support members 33 and of the bead 34 forming the surfaces of the grooves is fused to the fabric to hold the regions 40 in their deformed state. The bead at two positions adjacent the side edges of the layer of fa~ric near the extension 38 is devoid of a groove so that the fabric at these edge positions 41 (Figure 13) is not deformed nor is it fused to the bead. The fabric other than at the deformed regions 40 is in a substantially planar condition and is held in ten-sion between the deformed regions as it extends beneath the cells 31.
To ma~e the 80il support of the second embodiment, the rigid fabric support structure of support members and edge frame is preformed by injection moulding. The inverted soil support i8 then overlaid by the layer 30 of fabric and beneath a tool 42 (Figure 14) for fusing the fabric and sur-faces of the U-shaped channels together by welding. The tool 42 is a high frequency or ultrasonic welding tool but may also be a heated tool for softening and ~elting the materials of the fabric and support members ~y heat. The tool has a lower surface formed with ribs 43 in a shape sub-stantially complementary to the shape of the grooves 35.To weld the fabric and support members together, the tool is lowered to insert the ribs into the grooves 35 as shown in Figure 15. As the tool descends, it deforms the fabric into the g~ooves until these deformed regions mutually contact the surfaces of the grooves of the members 33 and of the bead 34. ~his defor,mation procedure causes stretching and tensioning of the fabric across the cells 33. It is advisable to have the ribs 43 sufficiently high to provide a gap between the tool and the fabric across cells 33 when the tool is firmly seated within the channels as showr. in ~ 7 ~

Figure 15. The welding operation then takes place in a manner known to skilled persons in the thermoplastics art, and the tool is then remo~ed while leaving fabric and support members firmly welded together.
In the second embodiment, sagging of the fabric is again prevented because of ten~ion in and firm holding of the fabric. Also, as the welding process either destroys or fills the interst~ces in the fabric in the deformed regions, water cannot flow by capillary action from one side of a support member to another. ~ence, water is controlled to flow along the fabric at positions 41 only, then along its edges until it reaches a position halfway between ends of the structure. From here, the water flows laterally through the gap between longitudinally aligned deformed regions 40a and then towards ends of the structure between regions 40.
In a modification of the second embodiment (not shown), a soil support is of exactly the same structure as in the second embodiment except that the deformed regions 40 of the Labric are not held within the grooves by welding.
In the modification, glue is applied to the surfaces defining the grooves and the deformed regions 40 are held against these surfaces and are permanently secured thereto by a tool formed with ribs of similar construction to the tool 42 in the.secQnd embod~nt.
Tn a third embodiment, shown in Figures 16 and 17, a soil support comprises a fabric support structure 29 of the same construction as the ~tructure 29 in the second embodiment with a plan view identical to that of Figure 12.
Like references will be used for the parts of structure 29 descrlbed in the second embodiment.

7~

The structure 29 of the third embodiment supports a layer 44 of fabric of the same construction as that des-cribed in the other embodiments. The layer 44 is held against the support structure 29 with deformed regions 45 of the fabric within the grooves 35 by a secondary support structure 46. This support st~ucture 46 is of sufficient size only to cover the area occupied by the grooves 35 in the support members 33 and the bead 34 underlying the layer 44. The support structure 46 is formed by injection moulding and comprises two sets of bars 47, the bars in each set lying side-by-side and in parallel relationship with each bar being integrally formed at one end with a main lateral bar 48.
Subsidiary bars 4g extend between side-by-side bars 47 to maintain their-lateral setting. The two sets of bars are ~oined by subsidiary longitudinal bars 50 which extend between longitudinally aligned bars of the two sets The bars 47 and 48 are tapered in cross-section complementary to the grooves 35 (Figure 17) and are relatively disposed so as to fit into the grooves 35 and sandwich the deformed regions 45 of the layer 44 between the support members 33 and ~ead 34 on the one hand, and the bars 47 and 4B on the other. The subsidiary bars 49 and 50 are of smaller cross-sectional area than the bars 47 and 48 and are not held closely against the fabric layer as may be seen from Figure 17. The deformed regions 45 of layer 44 are secured to the surfaces of grooves 35 and to the bars 47 by welding together of the thermoplastics material of the bars 47 and support members 33 with accompanying flow of thermo-plastics material through the interstices in the fabric.
3Q The soil support of the third embodiment is ~ 7 0 assembled by superposing the structures 29 and 46 with the layer of fabric between them and beneath a high frequency, ultrasonic or heating tool 51 as shown in Figure 18. The tool is then lowered to force the bars 47 into the grooves 35 while deforming the regions 45. The tool is then activated to cause a welding operation to take place.
In the completed soil support, water is controlled to flow from a flexible end 52 through edge regions 53 (Figure 16) not occupied by bars 47 and 48 and from thence along opposite edges of the layer 44 until it reaches the bars 50. As these bars 50 are not welded to or through the fabric, the water may then flow laterally above the bars 50 and then longitudinally between the bars 47 of each set.
In a modification of the fourth embodiment (not shown), instead of the assembly being made by welding, glue is disposed either within the grooves 35 or on the tapered surfaces of bars 47 and 48 to stick the deformed regions 45 of fabric.
In a fourth embodiment (Figure 19), a soil support has a rectangular fabric support structure 54 and a secondary support structure 55 which are, respectively, of similar construction to the structures 29 and 46 of the third embodiment and the same reference numerals will be used for like parts.
The structures 54 and 55 differ from their counter-parts in the third embodiment, however, in that certain of the subsidiary lateral bars 5~ of structure 55 and lateral support members 57 of structure 54 are wider than the bars 49 and support members 37 described above. These wider bars and members 56 and 57 are superposed one above the ~ 7 0 other in the assembly and are of sufficient width to accommodate rivets 58 passing through them and through the fabric to hold the assembly together. The rivets form a mechanical locking means for the assembly. In the assembly, no welding or glueing is necessary to hold the deformed regions 45 of fabric in place between the support members 33 and bars 47 as the deformed regions are held tightly gripped between these elements.
The construction of the fourth embodiment, while ensuring there is tension in the fabric layer extending between support member~ 33, does not prevent the flow of water through the deformed regions as the interstices in these regions are not bloc~ed. The fifth embodiment does not control the flow of water through the fabric, therefore, as in the previous embodiments.

Claims (20)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of making a soil support for a plant container in which the support has a plurality of fabric support members defining openings between them and a layer of substantially inextensible water-absorbent fabric extending across the openings in planar manner, the method comprising causing deformation of the fabric out of its plane in at least one region of the fabric and securing the deformed region to a support member to retain said region in its deformed state.

2. A method according to Claim 1 comprising causing deformation of the fabric in said one region by holding the layer of fabric within an open injection mould, closing the mould to hold the fabric facing across the flow path of thermoplastics material to be injected into a mould cavity for moulding the support member, and injecting the thermo-plastics material into the mould to form the support member, the pressure of the material being injected forcing said region of fabric which lies adjacent the cavity, into the cavity so as to deform said region, the thermoplastics material in said support member, after cooling, retaining the region in its deformed condition.

3. A method according to Claim 2 wherein during injection of the thermoplastics material into the mould cavity, some of the material flows through interstices in the fabric in said one region so as to embed parts at least of said region within the support member.

4. A method according to Claim 1 wherein deformation of the fabric is caused in at least two spaced-apart regions by the application of pressure to one surface of the fabric to place tension in the fabric between the two regions, and the deformed regions are secured to at least two spaced-apart support members, one region to each member, the support members being retained spaced-apart to hold the fabric in tension between said regions.

5. A method according to Claim 4 comprising causing deformation in said regions by holding the fabric within an open mould, closing the mould to hold the fabric facing across the flow path of thermoplastics material to be injected into mould cavities for moulding the support members, and injecting the thermoplastics material into the mould to form the support members, the pressure of the material being injected forcing said spaced-apart regions of fabric, which lie adjacent the cavities, into the cavities so as to deform said regions and place tension in the fabric between the members, the thermoplastics material in the support members, after cooling, retaining the regions in their deformed condition.

6. A method according to Claim 5 wherein during injection of the thermoplastics material into the mould cavity, some of the material flows through interstices in the fabric in said regions so as to embed parts at least of the regions within the support members.

7. A method according to Claim 5 comprising making the support as a part of a continuous process for making supports in which an indefinite length of fabric is passed intermittently along a path and through an injection mould-ing machine and has support members moulded thereto, said spaced-apart support members being spaced-apart laterally of the fabric and the fabric being placed in tension laterally across it by deformation of said regions into said cavities.

8. A method according to Claim 4 wherein the support members form part of a preformed fabric support structure and said support members have non-planar surface parts on one side of the structure and the fabric is disposed on said one side of the structure and the regions of fabric are deformed into contact with the non-planar surface parts of said support members and are held in deformed state against said surface parts.

9. A method according to Claim 8 wherein at least one of the support structure and the fabric is formed from thermoplastics material and the method comprises welding the deformed regions of fabric to the non-planar surface parts.

10. A method according to Claim 8 wherein the deformed regions of fabric are held to the non-planar surface parts by the application of adhesive.

11. A method according to Claim 8 wherein the fabric is deformed and then held in deformed state by disposing it between the fabric support structure and a secondary support structure which has surface parts which are substantially complementary to the non-planar surface parts of said support members, deforming said fabric regions by bringing said first mentioned and secondary support structures together with the complementary surface parts interfitting one with another, and retaining the first mentioned and secondary support structures together in an assembly.

12. A method according to Claim 11 wherein the first mentioned and secondary support structures are formed from thermoplastics material and are retained together by welding their non-planar surface material together by causing it to flow through interstices in the fabric.

13. A method according to Claim 11 wherein the first mentioned and secondary support structures are retained together by applying adhesive to their non-planar surface parts before they are brought together.

14. A method according to Claim 11 wherein the first mentioned and secondary support structures are retained together by applying a mechanical locking means to the assembly.

15. A soil support for a plant container having a plurality of fabric support members defining openings between them and a layer of substantially inextensible water-permeable fabric extending across the openings in planar manner, at least one region of the fabric being held in a condition deformed from the plane of the fabric by a support member to which said region is secured.

16. A soil support according to Claim 15 wherein the support members are formed from thermoplastics material and said at least one region of the fabric is at least partly embedded within the thermoplastic material of said support member.

17. A soil support according to Claim 15 wherein said support member has non-planar surface parts and the deformed regions of fabric are welded to the non-planar surface parts.

18. A soil support according to Claim 15 wherein said support member has non-planar surface parts and the deformed regions of fabric are held to the non-planar surface parts by adhesive.

19. A soil support according to Claim 17 wherein a secondary support member is provided which has surface parts which are substantially complementary to the non-planar surface parts of the first mentioned support member and the deformed region of the fabric is held between the com-plementary non-planar surface parts of the support members by the adhesive.

20. A soil support according to Claim 15 wherein said support member has non-planar surface parts and a secondary support member is provided and which has surface parts which are substantially complementary to the non-planar surface parts of the first mentioned support member, and the deformed region of the fabric is held between the complementary non-planar surface parts and mechanical locking means are provided which clamp the support members together with the deformed region of fabric between them.