AU2012203383A1 - A horticultural mat - Google Patents

Abstract

- 19 A horticultural mat that has a non woven base layer comprising of at least one fibrous material with plant seeds distributed in the base layer. A backing layer is engaged to the base layer that can let shoots of growth from said seeds through. Water absorbent particles are captured between the base layer and backing layer. 29y v FIGffURE 3

Description

Regulation 3.2 AUSTRALIA PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: WOOLGRO HOLDINGS LIMITED Actual Inventors: LUKE, Geoffrey Ian; LUKE, Ian James Address for service AJ PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT in Australia: 2601, Australia Invention Title: A Horticultural Mat The following statement is a full description of this invention, including the best method of performing it known to us.

- 2 The present invention relates to a horticultural mat. Mats for growing plants such as vegetables and grass from seed exist in many forms including in the form where seeds are captured in a biodegradable fibre mat. Such a mat is able to be placed on the ground in an environment that then allows for the seeds to germinate and grow roots into the underlying ground, whilst the rest of the plant grows up out of the mat. Grass can be grown in this manner. The seed mat can be supplied in rolls and rolled out over large areas. With good and even seed spread across the mat, grass can grow in a well distributed manner across the area with the support of regular watering and other desirable growing conditions. Seed mats are for example described in NZ 527017. That patent specification describes mats capable of biodegradation so that at some time after initial use, there is no evidence of the grass having been grown from seed retained by the mat. However such seed mats as described in NZ 527017 have a number of disadvantages including disadvantages relating to moisture retention during prolonged periods of hot or dry weather and lack of regular irrigation. The mats described in NZ 527017 are also prone to movement during windy conditions or on steep gradients, unless they are pegged or otherwise held down. The translucent nature of the mat of NZ 527017 can also result in the seeds being subjected to direct sunlight that can have adverse effects to the stimulation of plant growth. It is therefore an object of the present invention to provide a horticultural mat that addresses at least some of the abovementioned disadvantages and/or which will at least provide the public with a useful choice. Accordingly, in a first aspect the present invention may be said to be a horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) plant seeds distributed in the base layer, (c) a backing layer engaged to the base layer that can let shoots of growth from said seeds through, and (d) water absorbent particles captured between the base layer and backing layer. Preferably the base layer is comprised of animal wool. Preferably the base layer is comprised of a vegetable fibre, preferably jute. Preferably the base layer is comprised of animal wool and vegetable fibre (preferably jute). Preferably the animal wool is sheep's wool. Preferably the sheep's wool is unscoured or predominantly unscoured sheep's wool. Preferably the sheep's wool is a blend that includes unscoured or predominantly unscoured sheep's wool.

- 3 Preferably the sheep's wool is blend of scoured and unscoured sheep's wool. Preferably the sheep's wool is dag wool. Preferably the sheep's wool is raw wool. Preferably the base layer is comprised of at least 50 % by weight of animal wool. Preferably the base layer is comprised of 50 % by weight of animal wool and 50 /0 by weight of vegetable fibre. Preferably the horticultural mat is flexible. Preferably the horticultural mat is biodegradable. Preferably the water absorbent particles are comprised of a cellulosic material. Preferably the water absorbent particles are comprised of a cellulosic pulp or mulch. Preferably the water absorbent particles are comprised of corn starch. Preferably the water absorbent particles are comprised of corn starch and of a cellulosic material. Preferably the water absorbent particles are distributed over the base layer. Preferably the water absorbent particles are no greater than 3cm in any given dimension. Preferably the seeds are contained in the base layer, generally proximate more the major surface of the base layer that is contiguous the backing layer than the other major face that is distal more the backing layer. Preferably the seeds are generally spaced from said backing layer by part of said base layer. Preferably the base layer comprises of a plurality of plies. Preferably the plies each comprise of an animal wool. Preferably each ply is of the same constitution. Preferably the base layer comprises of at least 3 plies the seeds retained generally between two of said plies. Preferably the base layer comprises of at least 5 plies, the seeds retained generally between two plies that locate said seeds generally more proximate one major face of said base layer. Preferably the base layer has been needle punched to consolidate the plurality of plies. Preferably the backing layer is of single ply of material. Preferably the backing layer is contiguous the base layer. Preferably the backing layer is coextensive the base layer. Preferably the backing layer comprises of jute. Preferably the backing layer comprises of paper. Preferably the paper is of less than 100gsm.

-4 Preferably the paper is less than 85gsm. Preferably the paper is 80gsm. Preferably the backing layer has been needle punched to consolidate it with said base layer. Preferably the backing layer has been needle punched simultaneously with said plies of said base layer being needle punched. Preferably the assembly of the backing layer and the base layer has been needle punched by said needles penetrating first through said base layer and then through said backing layer. Preferably the paper is selected to be of a kind that when wet it is of a darker colour than when dry.. Preferably the paper is more reflective of sunlight when dry than when wet.. Preferably the paper is brown in colour.. Preferably the paper is cream in colour.. Preferably the backing layer is perforated.. Preferably the backing layer is perforated by virtue of having been needle punched.. Preferably the backing layer includes openings to allow plant shoots to grow through.. Preferably the backing layer includes regions of weakness to allow plant shoots to more readily grow there through than through other regions of said backing layer.. Preferably the openings and/or regions of weakness are in addition to the needle punched perforations.. Preferably the regions of weakness are perforations or score lines or slits.. Preferably there are perforations or score lines or slits extend in a unidirectional manner over said backing layer.. Preferably the seeds are grass seeds. Preferably wherein the seeds are of at least one type of vegetable.. Preferably the seeds are evenly distributed.. Preferably the moisture absorbing particles are evenly distributed.. Preferably the base layer is of a density to, in use, allow roots to grow from said seeds and into ground below the mat.. In a further aspect the present invention may be said to be a horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) water absorbent particles and plant seeds captured between the base layer and backing layer, - 5 wherein said backing layer is able to let shoots of grow from said seeds through. In a further aspect the present invention may be said to be a biodegradable horticultural mat suitable for use as a substrate for growing plants from seed, said mat comprising an assembly of layers including a layer of non woven fibrous material and a layer of cellulosic material, wherein between said layers is a water absorbent material. Preferably the cellulosic material comprises paper. Preferably the assembly has been needle punched. Preferably seeds are distributed across said mat and are preferably located in or on said layer of non woven fibrous material. In a further aspect the present invention may be said to be a horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located in at least one of the base layer, and layer of water absorbent particles, wherein said backing layer is able to let shoots of grow from said seeds through. Preferably the plant seeds are located in the layer of water absorbent particles in an evenly distributed manner. In a further aspect the present invention may be said to be a horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located between at least one of (a) the base layer and layer of water absorbent particles and (b) the backing layer and the layer of water absorbent particles, wherein said backing layer is able to let shoots of grow from said seeds through. Preferably the plant seeds are bonded to the backing layer. In a further aspect the present invention may be said to be a dual mode horticulture mat for propagating grass from seed retained by the mat, the mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, -6 (d) plant seeds located in at least one of the base layer, and layer of water absorbent particles, wherein the mat is capable of being positioned on the ground at where the grass it to be propagated in a manner selected from one of a first mode where the base layer is located above the backing layer and a second mode where the backing layer is located above the base layer. In a further aspect the present invention may be said to be a dual mode horticulture mat for propagating grass from seed retained by the mat, the mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located between at least one of (a) the base layer and layer of water absorbent particles and (b) the backing layer and the layer of water absorbent particles, wherein the mat is capable of being positioned on the ground at where the grass it to be propagated in a manner selected from one of a first mode where the base layer is located above the backing layer and a second mode where the backing layer is located above the base layer. In a further aspect the present invention may be said to be a method of growing plants using a mat as hereinbefore described. In a further aspect the present invention may be said to be a method of growing plants using a mat as hereinbefore described and as shown with reference to the drawings. In a further aspect the present invention may be said to be a method of growing plants on ground that includes a gradient of greater than 30 degrees, using a mat as hereinbefore described as the plant propagation medium. In a further aspect the present invention may be said to be a method of growing plants on ground that will be subject to wind speeds exceeding 20 knots, using a mat as hereinbefore described as the plant propagation medium. In a further aspect the present invention may be said to be a method of growing plants as hereinbefore described wherein the method requires no additional securing of the mat to the ground. In a further aspect the present invention may be said to be a method of manufacturing a horticultural mat comprising advancing a layer of non woven fibrous material together with a backing layer through a needle punching station to effect a needle punching of the layers together, the needles of the -7needle punching station first penetrating said layer of non woven fibrous material and then said backing layer. In a further aspect the present invention may be said to be a method of manufacturing a horticultural mat comprising, needle punching a layer of non woven fibrous material together with a backing layer, by driving the needles first through said layer of non woven fibrous material and then through said backing layer. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. Where reference herein is made to ground it is to be understood to include soil or any other medium into which roots of a plant can establish themselves. A preferred form of the present invention will now be described with reference to the drawings in which: Figure 1 shows a perspective view of a mat located on ground and grass growing, Figure 2 is a sectional view of one example of the mat, Figure 3 is a exploded view of figure 2, Figure 4 shows the base layer, Figure 5 show the mat, having been needle punched, Figure 6a shows part of the mat with gashes of slits provided in the backing layer, Figure 6b shows perforations or lines of weakness in the backing layer, Figure 6c shows the seeds in the mat with seeds bonded or glued to the backing layer with the mulch layer placed directly over, Figure 6d shows the mat with seeds distributed onto and into the mulch layer, Figure 6e shows the mat with seeds distributed in the base layer or to the various layers of the base layer, Figure 7 shows a process of manufacture of the mat, Figure 8 shows the needle punching station, Figure 9 shows the station in the process of manufacture at where the perforations, gashing or slitting of the base layer may occur, Figure 10 shows a graph of germination times for different mat compositions, and Figure 11 shows a graph of germination times where the mat has been positioned in the two different modes of use.

-8 With reference to the version of the mat of figure 2, the present invention includes a mat 1 that can assist in the growth of plants on ground 2. The mat is able to be appropriately placed on ground 2 be a person for such purposes. The plants to be grown may be grass or vegetables. The mat 1 includes a base layer 3 that is preferably constituted of a fibrous material such as an animal fibre such as wool. The wool may be sheeps wool. It may be dag wool, raw wool or unscourred wool. This base layer 3 may also include jute. This may be homogenously blended with the wool. The fibrous layer preferably consists of an even blend of jute and wool at a percentage by weight of approximately 50-50 percent. The base layer 3 is preferably constituted in a process that includes a carding process. The fibres are hence preferably non-woven. The base layer 3 may be constituted of multiple plies 8 as shown in figure 4. For example there may be 2-10 plies that through a needle punching process may be consolidated into a final form base layer of the mat 1. In one form of the mat, retained by and preferably in the base layer 3 (preferably intermediate of two plies) may be seeds. The seeds are substantially evenly distributed. In the process of capturing seeds in the base layer 3, the seeds may be deposited onto one of the plies whereupon the subsequent ply is placed on top. In such a way the seeds can become trapped within the fibres of the base layer 3. In one preferred form where multiple plies are utilised the seeds are located between two plies of the base layer 3 that are proximate more one of the face sides of the base layer. For example the seeds may be located towards one of the major surfaces of the base layer. Preferably the major face is the one that will be distal most from the ground on which the mat will be placed. Located adjacent one of the major sides of the base layer 3 and preferably contiguous therewith is a backing layer 6. It is preferably a ply of material that captures a moisture or water absorbent material 5. The water absorbent material 5 may be a cellulosic mulch or pulp. It is preferably located against the major face of the base layer 3 and secured thereto by a needle punching process. The cellulosic mulch 5 is preferably a post consumer newsprint pulp. It is particulate in constitution so that shoots of growth from the seed 4 below can migrate up and out through the backing layer 6. The cellulosic mulch is preferably located proximate to the seeds. The cellulosic mulch is preferably particulate and may be of particle size of between 2mm - 10mm. The pulp is able to retain moisture which in a dry and/or hot climate can help retain moisture and assist in preventing the seeds from drying out during germination.

- 9 In one mode of use the mat of figure 2 may be placed on the ground so that the base layer is below the backing layer and preferably the ground contacting layer. In another mode of use, the base layer may be above the backing later and preferably be the top most layer. The combination of the fibrous material of the base layer and the provision of the backing layer and water retention material can create a good environment to stimulate germination and plant growth. The use of jute can also contribute to this as jute has good water absorption properties and water retention properties. In one mode of use of the mat, where the base layer is below the backing layer when placed on the ground, the backing layer can provide a certain degree of shade from direct sunlight to the seeds/initial growth which may otherwise be detrimental to growth in certain conditions. The backing layer can also help provide air climate control of the air between the backing layer and the ground. It can help trap or partially trap such air, particularly in windy conditions. The backing layer is preferably of a single ply construction. It is preferably a paper such as a sack craft paper that may be of approximately 80gsm. It is secured with and preferably to the base layer such as by way of needle punching. The paper is preferably of a colour such that when it is moist it is relatively dark compared to when it is dry. In a mode of use where the paper layer is positioned to be upper most, when the paper is dry it is in a lighter colour and therefore is more reflective of light whereas when it is wet and dark it is more absorbent of heat which can help in the seed germination and growth of the grass. The changing of the colour of the paper can also help identify when it is time to apply water to the mat. In use the mat may present the paper backing layer as the top most layer. Roots growing from the seeds extend downwardly and away from the backing paper to penetrate the ground 2 below. Over time the mat will deteriorate and eventually biodegrade, having served its primary purpose of establishing plants in the ground. The paper backing layer 6 is preferably needle punched with the base layer so as to bond these two together. To assist with the growth of new plants through the paper layer the paper layer may be weakened or have apertures therethrough through which the grass can grow. Such are indicated as 10a and 10b in figures 6a and b. Without such weakness or aperture in addition to the needle punched holes, grass may not grow easily through the paper. Whilst a thinner layer of paper may be utilised that is more easily ruptured by plant growth coming up, paper thinner than 80gsm becomes less manageable in the process of manufacture of the mat. Alternatively the mat may be positioned with the base layer being upper more or most as shown in figures 6c,de. The seeds may also be located in positions different to being in the base layer.

- 10 Figure 6c shows the seeds in the mat with seeds bonded or glued to the backing layer with the mulch layer placed directly over, Figure 6d shows the mat with seeds distributed onto and into the mulch layer, Figure 6e shows the mat with seeds distributed in the base layer or to the various layers of the base layer, Figure 7 shows a simplistic view of the process of manufacture with reference to the version of the mat as shown in figure 2. The process may be a continuous manufacture process. Paper to define the backing layer 6 may be advanced with a pre or post needle punched base layer 3 through a needle punching station 12. The needle punching station 12 joins the paper and base layer together. It may also needle punch the base layer for the first time to consolidate it into a more dense/compact form. The paper may carry with it the pulp 5 as shown to ensure it becomes captured between the paper layer and the base layer. Seeds may already be located in the pre-needle punching station base layer. The needle punching station as shown in figure 8 includes a needle press or board 15 and a base 16 into which the needle can partially extend. The paper layer runs over the base 16 and keeps the base layer from running over it. This is important when the base layer comprises of unscoured wool and the lanolin from the wool can have tendency to clog the needle receiving holes of the base 16. Then needle punching station includes a press to more the move the needle board 15 and base 16 relative to each other to drive the needles through the base layer and paper backing layer. The needles first penetrate the base layer 3, then the backing layer 5. A device 13 may be used for a post needling punching weakening of the backing layer. The device 13 may be a roller that includes teeth 18 that can rupture the paper. The roller may be mounted with its rotational axis 20 perpendicular to the machine direction 21. The roller may extend across the width of the mat advancing through the process so as to create weakness or slits or openings in the paper at regular intervals over the entire mat. Alternatively the paper may be pre-weakened prior to it being incorporated with the base layer. The paper may include slits of perforations that exist prior to the needle punching steps. Such weakness/perforations may include a plurality of parallel lines of such, that each extend parallel to the machine direction 21. In this way such lines do not significantly compromise the longitudinal strength of the paper. Which can be important if the paper is under tension during the process of manufacture of the mat. Some of the advantages that the present invention offers include the following: The pulp can absorb and retain moisture. This can 0 Help with seed growth - 11 o Weigh down the mat to reduce the prospect it may move in windy or high gradient conditions. . The backing layer, as well as capturing the pulp, can provide (i) some shade from direct sunlight for the seeds, (ii) some moisture retention capacity, (iii) a cover to trap a humid/warm environment around the seeds/seedlings, (iv) for reduced downtime in production particularly due to better needle punching performance. * The openings and/or weakness in the paper layer have been shown to allow easier growth of plants there through compared to other areas of the paper. Controlled experiments and field tests have both shown advantages to laying the mat base layer up and backing layer up depending on site conditions such as soil conditions, and the amount of irrigation or expected rain fall. Examples will now be given of mat configurations and how such may be used. Dry or very dry conditions: Mat specification: Seed is bonded or glued to the backing layer with the mulch layer placed directly over the seeded backing layer as shown in figure 6c. Installation: The mat can be laid with the seed bonded backing layer facing down in direct contact with the soil. This method allows the seeds to be in direct contact with both the moisture retaining backing layer and the moisture retaining pulp layer thus making good use of all the available irrigation or natural rain fall. A fine layer of soil can be placed over the entire mat further helping the retention of moisture. This system works well in dry hot conditions when retaining moisture around seeds to encourage germination is traditionally difficult. If the mat is subject to too much rain fall or irrigation the backing and mulch layer can hold excessive moisture around the seed for too long a period of time thus starving the seed of oxygen and delaying the germination process. Dry or moderately dry conditions: Mat specification: Seed is distributed onto and into the mulch layer as shown in figure 6d. Installation: The mat can be laid with the backing layer facing down i.e. in contact with the soil or with the backing layer facing up i.e. the backing layer facing the sky. This method allows the seeds to be in direct contact with the moisture retaining pulp and the free draining backing layer of fibre offering good levels of moisture retention around the seed with the ability to drain away excessive irrigation or rain fall when necessary.

- 12 This system works well during the warmer seasons when moderate irrigation is available. There is a risk of seed saturation during heavy rain fall or irrigation but this risk has been shown to be lesser than the mat with seed bonded to the backing layer. Average conditions: Mat Specification: Seed is distributed in the base layer or to the various layers of the base layer as shown in figure 6e. Installation: The mat can be laid with the backing layer facing down i.e. in contact with the soil or with the backing layer facing up i.e. the backing layer facing the sky. This method allows the seeds and fibre to benefit from the moisture retaining pulp. If the mat is laid backing layer down this layer helps slow the transmission of irrigation or rain fall through the mat and away from the seeds by trapping the moisture in the mulch and backing layer. A fine layer of soil can be placed over the entire mat further helping the retention of moisture. During wet conditions the mat can be laid base layer down & backing layer up reducing the chances of seed saturation due to the free draining nature of the base layer. This works well during changeable weather both during warmer seasons and through winter. The seed is insulated in the base layer protecting it from low soil temperatures. There is much lower risk of seed saturation during heavy rain fall or irrigation. This risk has been shown to be lesser than the mat with seed bonded to the backing layer and the seed in the pulp layer. Trails were conducted to determine the effectiveness of certain variables. It was established that a number of variables effect the speed and rate at which grass seed germinates in the mat. The variables most dramatically effecting germination are moisture and temperature. The purpose of the trial was to establish the differences observed under dry conditions by altering the composition of the mat. Five variations of the mat were created against a control. Trials 1. Mat as described with reference to figure 2 2. Pure Wool 3. Wool/Jute/Mulch 4. Wool/Jute/Paper 5. Wool/Paper 6. Wool/Jute/Paper -seed bonded 7. Paper Side Up Trial 8. Paper Side Down Trial - 13 Six planter boxes were filled with the same quantity and source of topsoil. The six mats were then laid onto this soil and a fine layer of top soil added. All mats received equal watering throughout the trial. Daily visual measurements were taken via a grid analysis method and the results graphed. The results are shown in the graph of figure 10. A second trail was run to confirm the benefit of laying the mat paper side down in dry conditions. The results are shown in the graph of figure 11. The results from the trial demonstrated that under dry conditions where moisture may be a limiting factor to germination, the absorption by materials of water and the holding of this water in close proximity to the seed will enhance germination over and above the control. The results confirm that a mat manufactured with wool, jute and shredded paper combination was superior to all other trialled combinations, importantly showing a significant benefit over a wool only mat. The trial confirmed that mats laid paper side down in dry conditions are superior, the opposite is likely in wet - winter conditions and this will enable the invention to be used appropriately based on year round installation decisions and recommendations where moisture is a significant variable.

Claims (58)

1. A horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) plant seeds distributed in the base layer, (c) a backing layer engaged to the base layer that can let shoots of growth from said seeds through, and (d) water absorbent particles captured between the base layer and backing layer.

2. A mat as claimed in claim 1 wherein the base layer is comprised of animal wool.

3. A mat as claimed in claim 1 or 2 wherein the base layer is comprised of a vegetable fibre, preferably jute.

4. A mat as claimed in any one of claims 1 to 3 wherein the base layer is comprised of animal wool and vegetable fibre (preferably jute).

5. A mat as claimed in claim 2 or 4 wherein the animal wool is sheep's wool.

6. A mat as claimed in claim 5 wherein the sheep's wool is unscoured or predominantly unscoured sheep's wool.

7. A mat as claimed in claims 5 or 6 wherein the sheep's wool is a blend that includes unscoured or predominantly unscoured sheep's wool.

8. A mat as claimed in any one of claims 5 to 7 wherein the sheep's wool is blend of scoured and unscoured sheep's wool.

9. A mat as claimed in claim 5 wherein the sheep's wool is dag wool.

10. A mat as claimed in claim 5 wherein the sheep's wool is raw wool.

11. A mat as claimed in any one of claims 1 to 10 wherein the base layer is comprised of at least 50 % by weight of animal wool.

12. A mat as claimed in any one of claims 1 to 11 wherein the base layer is comprised of 50 % by weight of animal wool and 50 % by weight of vegetable fibre.

13. A mat as claimed in any one of claims 1 to 12 wherein the horticultural mat is flexible.

14. A mat as claimed in any one of claims 1 to 13 wherein the horticultural mat is biodegradable.

15. A mat as claimed in any one of claims 1 to 14 wherein the water absorbent particles are comprised of a cellulosic material.

16. A mat as claimed in any one of claims 1 to 15 wherein the water absorbent particles are comprised of a cellulosic pulp or mulch.

17. A mat as claimed in any one of claims 1 to 16 wherein the water absorbent particles are comprised of corn starch.

18. A mat as claimed in any one of claims 1 to 17 wherein the water absorbent particles are comprised of corn starch and of a cellulosic material. - 15

19. A mat as claimed in any one of claims 1 to 18 wherein the water absorbent particles are distributed over the base layer.

20. A mat as claimed in any one of claims 1 to 19 wherein the water absorbent particles are no greater than 3cm in any given dimension.

21. A mat as claimed in any one of claims 1 to 20 wherein the seeds are contained in the base layer, generally proximate more the major surface of the base layer that is contiguous the backing layer than the other major face that is distal more the backing layer.

22. A mat as claimed in any one of claims 1 to 21 wherein the seeds are generally spaced from said backing layer by part of said base layer.

23. A mat as claimed in any one of claims 1 to 22 wherein the base layer comprises of a plurality of plies.

24. A mat as claimed in claim 23 wherein the plies each comprise of an animal wool.

25. A mat as claimed in claim 23 or 24 wherein each ply is of the same constitution.

26. A mat as claimed in any one of claims 1 to 25 wherein the base layer comprises of at least 3 plies the seeds retained generally between two of said plies.

27. A mat as claimed in any one of claims 1 to 26 wherein the base layer comprises of at least 5 plies, the seeds retained generally between two plies that locate said seeds generally more proximate one major face of said base layer.

28. A mat as claimed in any one of claims 23 to 27 wherein the base layer has been needle punched to consolidate the plurality of plies.

29. A mat as claimed in any one of claims 1 to 28 wherein the backing layer is of single ply of material.

30. A mat as claimed in any one of claims 1 to 29 wherein the backing layer is contiguous the base layer.

31. A mat as claimed in any one of claims 1 to 30 wherein the backing layer is coextensive the base layer.

32. A mat as claimed in any one of claims 1 to 31 wherein the backing layer comprises of jute.

33. A mat as claimed in any one of claims 1 to 31 wherein the backing layer comprises of paper.

34. A mat as claimed in claim 33 wherein the paper is of less than 100gsm.

35. A mat as claimed in claim 33 or 34 wherein the paper is less than 85gsm.

36. A mat as claimed in any one of claims 33 to 35 wherein the paper is 80gsm.

37. A mat as claimed in any one of claims 1 to 36 wherein the backing layer has been needle punched to consolidate it with said base layer. - 16

38. A mat as claimed in any one of claims 1 to 37 wherein the backing layer has been needle punched simultaneously with said plies of said base layer being needle punched.

39. A mat as claimed in any one of claims 1 to 38 wherein the assembly of the backing layer and the base layer has been needle punched by said needles penetrating first through said base layer and then through said backing layer.

40. A mat as claimed in any one of claims 1 to 39 wherein the seeds are grass seeds.

41. A horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) water absorbent particles and plant seeds captured between the base layer and backing layer, wherein said backing layer is able to let shoots of grow from said seeds through.

42. A biodegradable horticultural mat suitable for use as a substrate for growing plants from seed, said mat comprising an assembly of layers including a layer of non woven fibrous material and a layer of cellulosic material, wherein between said layers is a water absorbent material.

43. A biodegradable mat as claimed in claim 42 wherein the cellulosic material comprises paper.

44. A biodegradable mat as claimed in claim 42 or 43 wherein the assembly has been needle punched.

45. A biodegradable mat as claimed in any one of claims 42 to 44 wherein seeds are distributed across said mat and are preferably located in or on said layer of non woven fibrous material.

46. A horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located in at least one of the base layer, and layer of water absorbent particles, wherein said backing layer is able to let shoots of grow from said seeds through.

47. A mat as claimed in claim 46 wherein the plant seeds are located in the layer of water absorbent particles in an evenly distributed manner.

48. A horticultural mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and - 17 (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located between at least one of (a) the base layer and layer of water absorbent particles and (b) the backing layer and the layer of water absorbent particles, wherein said backing layer is able to let shoots of grow from said seeds through.

49. A mat as claimed in claim 48 wherein the plant seeds are bonded to the backing layer.

50. A dual mode horticulture mat for propagating grass from seed retained by the mat, the mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located in at least one of the base layer, and layer of water absorbent particles, wherein the mat is capable of being positioned on the ground at where the grass it to be propagated in a manner selected from one of a first mode where the base layer is located above the backing layer and a second mode where the backing layer is located above the base layer.

51. A dual mode horticulture mat for propagating grass from seed retained by the mat, the mat comprising: (a) a non woven base layer comprised of at least one fibrous material, (b) a backing layer engaged to the base layer, and (c) a layer of water absorbent particles captured between the base layer and backing layer, (d) plant seeds located between at least one of (a) the base layer and layer of water absorbent particles and (b) the backing layer and the layer of water absorbent particles, wherein the mat is capable of being positioned on the ground at where the grass it to be propagated in a manner selected from one of a first mode where the base layer is located above the backing layer and a second mode where the backing layer is located above the base layer.

52. A method of growing plants using a mat as claimed in any one of the preceding claims.

53. A method of growing plants using a mat as claimed in any one of claims 1 to 51 and as shown with reference to the drawings. - 18

54. A method of growing plants on ground that includes a gradient of greater than 30 degrees, using a mat as claimed in any one of claims 1 to 51 as the plant propagation medium.

55. A method of growing plants on ground that will be subject to wind speeds exceeding 20 knots, using a mat as claimed in any one claim 1 to 51 wherein as the plant propagation medium.

56. A method of growing plants as claimed in claim 55 wherein the method requires no additional securing of the mat to the ground.

57. A method of manufacturing a horticultural mat comprising advancing a layer of non woven fibrous material together with a backing layer through a needle punching station to effect a needle punching of the layers together, the needles of the needle punching station first penetrating said layer of non woven fibrous material and then said backing layer.

58. A method of manufacturing a horticultural mat comprising, needle punching a layer of non woven fibrous material together with a backing layer, by driving the needles first through said layer of non woven fibrous material and then through said backing layer.