GB2230929A

GB2230929A - Protective sleeve for plants

Info

Publication number: GB2230929A
Application number: GB9008212A
Authority: GB
Inventors: John Athelstan Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-05-05
Filing date: 1990-04-11
Publication date: 1990-11-07
Also published as: GB9008212D0

Abstract

A protective sleeve is designed to hold in its lower portion (3, 18, 33) a change of growth medium, such as soil or compost. A seed is planted in this and may be nurtured in a protective environment, but planting out can be immediate, the lower portion being buried in the ground, leaving the upper portion upright above ground, where it acts as a shield, support and guide for the growing plant. The sleeve may be integral or separable into the two portions. The upper portion will normally be translucent, and the material of the sleeve may be bio- or photo-degradable. Various configurations of both portions are described. <IMAGE>

Description

ImDrovements relatinq to protective devices for seeds and plants This invention relates to protective devices for seeds and plants, and is concerned with casings or sleeves which protect them when young.

Such sleeves are now well known, particularly in forestry, where young saplings are often so protected. The sleeve is generally made of translucent plastics material and is placed around the sapling after it has been planted.

Its lower end rests on the ground and usually a separate stake is provided, although sometimes the sleeve relies on the sapling for support.

Undoubtedly, such a sleeve does have considerable advantages in promoting and protecting plant growth, but there are certain disadvantages as well. The placement of the sleeve around the tender young plant can seriously damage it and a sapling needs to be two or three years old before it can cope with most tree guards. Therefore, saplings have to nurtured elsewhere for a considerable time before being planted out, and the longer that time and the larger the sapling when it is shifted, the more expensive the operation becomes. Then there is the cost of the stake and ties to be added to that of the sleeve.

It is believed that these disadvantages can be overcome and the principles also advantageously applied to plants other than young trees and saplings.

According to one aspect of the present invention there is provided a protective sleeve for plants comprising a tubular structure with a lower portion for containing a seed or seedling bed, for burial in the ground and for shielding the seed and the plant root as it develops, and an upper portion to protect the plant stem as that develops.

A seed will be planted in compost or other growth medium within the lower portion, and growth to a seedling stage may take place in controlled conditions, in a greenhouse for example. Then, within weeks or a few months, the package of sleeve plus seedling and compost is taken on site and the lower portion of the sleeve is buried in the ground. A firm supporting stake is provided for the developing plant by the sleeve itself. However, it will often be practical to plant immediately, without waiting for seedling growth, at the final site, the sleeve then forming a mini-greenhouse.

In one form, the upper portion has one or more longitudinal splits so that the sleeve can expand with growth and not unnecessarily restrict natural formation of the plant. But the sleeve will be stiff enough for there to be some resistance to the split opening, so that support is maintained throughout the expansion of the sleeve.

Preferably, this may be achieved by means embracing the sleeve, initially to resist opening of the or each longitudinal split. These means, or at least part of them, may be located at the junction of the upper or lower portions and serve as an indication as to how deep the sleeve should be buried. Various devices may be suitable, such as an elastic or split resilient collar allowing expansion, a twist of wire, adhesive tape, a wooden dowel through opposed holes or one or more elastic bands. Where wire is used, it may be ferrous so that it will rust away, its gauge being chosen so that it will do this in time for expansion of the plant. The tape may be degradable with a corresponding time span, and a wooden dowel would rot away.

Alternatively the sleeve may be glued in its initial condition, the adhesive used breaking down after a time to allow the split to open.

In a preferred embodiment, however, the upper portion may be bio- or photo-degradable. Thus a plant growing up within the structure may be protected for two or three years or more while the upper portion remains intact. But after a time, that portion will weaken and fall away, aided by the thrust of the plant itself. The lower portion, if integral with and therefore of the same material as the upper portion, will be subject to different conditions and, particularly if the material is photo-degradable, will last longer.

The upper portion will generally be transparent, or at least translucent, and it can be formed in various shapes.

For example, for some plants one might want a bulbous formation, for others one that flares outwardly at the upper end, and for yet others a substantially straight tube.

Towards the bottom of the upper portion, it may be advisable to pierce the sleeve with one or more drainage holes, to avoid the upper portion filling up with water.

The portions are preferably mutually detachable. Thus, while the upper portion may be translucent and degradable as suggested above, the lower portion may not be, or it may be of a different material having a different length of useful life.

This arrangement also allows the seedling to be developed in the lower portion alone, for example while that is in a greenhouse as mentioned above. Also, when planting out, the lower portion can be inserted into the ground first, and then the upper portion will be fitted to it. This makes the operation easier. There is also the advantage that the upper portion might be removed from time to time for inspection of the plant when that is small enough not to impede replacement without any disturbance of the root. If necessary, the first upper portion might be replaced with a larger upper portion which would also fit onto the one in the ground.

The mutual engagement may be a screw fitting, or an interference or snap-fit, and the upper portion may plug into the lower one or vice versa.

Preferably the lower portion will be skeletal or perforated to allow root development and drainage, and it may be longitudinally split to allow for expansion if necessary. In one favoured form the lower portion has at least one integral tag arranged to be urged outwardly by expansion of a plant root within. Conveniently each such tag is arranged, when urged outwardly, to form a barb resistant to extraction of the lower portion from the ground.

The lower portion may be bio-degradable and it will often be formed with one or more spikes or sharply pointed ends for easy insertion into the ground. As an alternative, it could be screw threaded, to be worked into a hole in the ground by rotation and to help retain the compost.

The lower portion may be shaped so that it is urged out of the ground as the roots of the plant develop. The lower portion may also be provided with internal formations such as downwardly extending ribs which tend to direct the roots of the plant downwardly.

As well as promoting growth, such sleeves will protect against frost and also against small animals such as mice and slugs. They will provide clear markers to be avoided when weeding or hoeing. Furthermore, separable upper portions and the non-degradable versions with lower portions with which roots do not entangle can be removed when the plant is substantial enough without damaging the plant, and they may be re-usable many times.

According to another aspect of the present invention there is provided a method of growing plants comprising filling the lower portion of a sleeve as defined above with a growth medium such as soil or compost, planting a seed or seedling therein, and part-burying the sleeve and its contents at a selected site leaving the upper portion exposed and upright.

For a better understanding of the invention, some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which the twelve figures are diagrammatic perspective views of various protective sleeves for plants.

In Figure 1, the sleeve is made up from two identical halves 1 with their edges which meet along join lines 2 formed so that there is an interengagement. The upper end of the sleeve is belled outwardly and the lower end also flares slightly and the halves 1 separate to form fluted spikes 3. The halves are kept together by at least one elastic band 4 and a collar 5 which is positioned so that it will seat on the ground. Just above this there is at least one drainage hole 6.

The sleeve 2 is of similar construction, but instead of an elastic band 4 there is a corrodible wire ring 7 and instead of the collar 5 there is a wooden peg 8 extending diametrically through the two halves.

The sleeve of Figure 3 is differently shaped having a swelling which reduces to a neck before the upper belled mouth. Also, at the lower end each half has two spikes with serrations 9 for a more positive grip in the ground.

Figure 4 shows an integral sleeve whose upper portion 10 is of larger diameter than the lower portion 11 and which flares slightly outwardly towards the top. The lower portion has spikes 12.

In Figure 5, the general shape is similar to that of Figure 4, but the upper portion 13 is separable from the lower portion 14, whose upper end is externally screw threaded at 15. The interior of the lower end of the portion 13 is complimentarily threaded to screw down to the lower portion.

This arrangement is reversed in Figure 6, where the upper portion 16 has its lower, narrowed end externally screw threaded at 17 to engage in the lower portion 18.

In Figure 7, the upper portion 19 again has its lower end fitting inside the lower portion 20, but this is split at 21 so that it can spread to accept this engagement. Its natural resilience will keep it firmly gripping the upper portion 19. The spiked formations at the lower end of the portion 20 leave plenty of room for root expansion, so that the split should not be prematurely widened to release the upper portion 9.

In Figure 8, the arrangement is reversed with the upper portion 22 having the upper end of a more tubular lower portion 23 engaged within its neck. Here, the split in the lower portion is constricted against its natural resilience to permit and retain the engagement. If the root expansion causes the split to widen below the overlap with the upper portion, the grip on that upper portion will become tighter.

Figure 9 shows another integral sleeve 24 but here the lower portion has perforations 25 through which the roots of the plant may grow.

The sleeve of Figure 10 also has a lower portion 26 with perforations 27 while the upper portion 28 plugs into the top of this sleeve.

The opposite arrangement is shown in Figure 11 where a similar lower portion 29 with perforations 30 plugs into the bottom of the upper portion 31. Internally, this is provided with an annular shoulder 32 to limit the overlap.

In Figure 12, the lower portion 33 has a lower tubular stem 34 with inverted U-shaped cuts or slots to form tags 35. These will be forced to hinge outwardly as the plant root develops and act as barbs progressively help anchorage in the ground. Two such tags 35 are shown; there could be just one, and there might be more than two. The mouth of the lower portion 33 may serve for a time as the upper portion of the sleeve, but its height may be augmented by a tube 36 which is a close fit over it. The lower end of the tube may be driven a short distance into the ground to add to the stability.

Claims

1. A protective sleeve for plants comprising a tubular structure with a lower portion for containing a seed or seedling bed, for burial in the ground and for shielding the seed and the plant root as it develops, and an upper portion to protect the plant stem as that develops.

2. A sleeve as claimed in Claim 1, wherein the upper portion is split to allow lateral expansion.

3. A sleeve as claimed in Claim 1 or 2, wherein the upper portion is bio- or photo-degradable.

4. A sleeve as claimed in Claim 1, 2 or 3, wherein the upper portion is transparent or translucent.

5. A sleeve as claimed in any preceding claim, wherein the bottom of the upper portion is pierced for drainage.

6. A sleeve as claimed in any preceding claim, wherein the portions are mutually detachable.

7. A sleeve as claimed in Claim 5, wherein the portions are complementarily screw threaded.

8. A sleeve as claimed in Claim 5, wherein the portions have interference or snap fit engagement.

9. A sleeve as claimed in any preceding claim, wherein the lower portion is skeletal or perforated.

10. A sleeve as claimed in any preceding claim, wherein the lower portion is split to allow lateral expansion.

11. A sleeve as claimed in any preceding claim, wherein the lower portion has at least one integral tag arranged to be hinged outwardly by expansion of a plant root within.

12. A sleeve as claimed in Claim 11, wherein the or each tag is arranged, when urged outwardly, to form a barb resistant to extraction of the lower portion from the ground.

13. A sleeve as claimed in any preceding claim, wherein the lower portion is bio-degradable.

14. A sleeve as claimed in any preceding claim, wherein the lower portion is spiked for easy insertion into the ground.

15. A sleeve as claimed in any one of Claims 1 to 11, wherein the lower portion is screw-threaded to be worked into a hole in the ground by rotation.

16. A sleeve as claimed in any preceding claim, wherein the lower portion is shaped so that it is urged out of the ground as the roots of the plant develop.

17. A sleeve as claimed in any preceding claim, wherein the lower portion is provided with internal formations which tend to direct the roots of the plant downwardly.

18. A protective sleeve for plants substantially as hereinbefore described with reference to the accompanying drawings.

19. A protective sleeve as claimed in any preceding claim, in combination with a change of growth medium such as soil or compost retained within the lower portion.

20. A method of growing plants comprising at least partially filling the lower portion of a sleeve as claimed in any one of Claim 1 to 19 with a growth medium such as soil or compost, planting a seed or seedling therein, and part-burying the sleeve and its contents at a selected site leaving the upper portion exposed and upright.