Plant Establishment Methods

The hardest part of growing plants in any problem area is the first year. A new plant has a greater chance of things going wrong than one that is well established:

*It can dry out more easily (because roots aren't deep into the natural soil where reserves of water can be drawn on hot days).
*There isn't sufficient plant mass to handle regrowing following a bad attack by insects or animals eating the foliage.
*The plant needs time to adapt to its new environment, which usually has much harsher growing conditions than the nursery in which it was grown. It must also overcome 'transplant shock' where it may be damaged, particularly its roots, during planting.

A key to establishing plants in any difficult area is to "nurture them" through the establishment phase. This involves providing protection and support and gradually reducing the degree of support, thus gradually exposing the plant to the difficult conditions of the site.


WAYS TO HELP PLANTS GET ESTABLISHED

Trickle And Drip Irrigation
The availability of cheap, flexible plastic piping and a variety of easily connected nozzle types makes trickle and drip irrigation systems a simple, cost effective means of irrigation for many gardens. Such systems provide a reliable source of moisture to your plants. This helps both plant establishment and subsequent growth.
Advantages:
*You can have a constant supply of moisture or a timed supply (as desired).
*Such systems are cheap and easy to install.
*It is easy to replace, repair, or get parts for such systems.
*Flow can be directed to individual plants so each plant gets a good irrigation. This means that overall water use is greatly reduced (water not wasted). This also makes such systems valuable in areas that have salinity problems (ie: rising water tables from over irrigation)
*Water can be supplied to the ground and not to foliage so there are fewer disease problems (eg: mildews).
Disadvantages:
*Blocked nozzles can often be a problem. These can sometimes be unblocked by simply turning your water source up as hard as possible so that whatever is blocking the nozzles is blasted clear by water. At other times you may have to disconnect the nozzle (usually quite simple) and blow hard through it to dislodge any obstructions. If this doesn't work you can try dislodging any obstructions with a sharp pointed object such as a needle. If all else fails simply replace the nozzle as they don't cost much.
*Nozzles and drippers need to be checked at regular intervals to make sure they haven't been knocked so that they no longer point in the desired direction.
*Sometimes moisture on the foliage is desirable.


Mulches
Mulches have a variety of benefits that assist in plant establishment and subsequent plant growth. These include:
1) Mulches help reduce competition to your plants by reducing weed growth.
2) Mulches help conserve moisture in the plants root zone.
3) Mulches consisting of organic materials provide nutrients and humus to the soil as they decompose thereby aiding plant nutrition and contributing to improved soil structure.
4) Mulches help buffer sudden changes in soil temperature that may damage plant roots.
5) Mulches help reduce erosion of top soil.

Mulches can be composed of inorganic materials (eg: rocks, gravel, synthetics, etc.) or organic materials such as used newspaper, manures, compost, leaf litter, straw, sawdust, etc.

Mulches come in two major forms: mat mulches, which are flat sheets or layers of materials such as plastic, newspaper, carpet underlay, weed mats, etc.
bulk mulches, which are comprised of quantities of loose material such as sawdusts, barks, leaf litter, grass cuttings, etc.

Bulk mulches are easy to place in position, however they are often easy to dislodge. Weed growth will usually penetrate bulk mulches more readily than mat types. Bulk mulches tend to be cheaper or more readily available than mat mulches. Some mat types prevent good water penetration (eg: plastic, paper & cardboard). Mat types need to be secured down ie. pegged to prevent them lifting. In general, the type of mulch you use will depend on such factors as cost, availability, ease of transport and the situation in which it is to be used.

For best results mulches should be applied at or just after planting. Before mulching it is best to kill or remove any existing vegetation. This is usually carried out by cultivation, hand weeding or by using weedicides. To be effective mulches should be thick enough to provide a good cover of the underlying surface but not too thick that it will smother your plants or be easily dislodged. As a general rule, bulk mulches should be at least 5 7cm thick, and in areas where weeds are a problem up to 10 15 cm thick. Ideally mulches, particularly organic types, should be kept clear of the plant stems or trunks.

Problems with mulches
*Mulches that consist largely of wood or bark products (eg: sawdust, pine bark) will draw nitrogen from the soil unless they are well composted before use. Addition of nitrogen fertilisers will overcome this problem.
*Some mulch materials, particularly those with fine particles, can pack together creating a barrier that repels water thereby reducing the amount of water reaching plant roots (eg: sawdust). Using a mixture of mulch materials or composting the material before use will reduce the likelihood of such problems occuring.
*The barks and saw dusts of some trees such as Pinus sp. and Eucalyptus sp. can contain materials that are toxic to other plants. Fresh material derived from these trees should be composted for at least six weeks before use to allow any toxins to leach out. Keeping the material moist and turning it frequently will help this process.
*Some mulch materials are very light and will easily blow away or be dislodged. Mixing such materials with other heavier materials will reduce the likelihood of this occuring.
*Slits in mat type mulches for plantings should be as small as possible and slit edges overlapped to reduce the likelihood of weeds becoming established around the base of the plants.

TREE GUARDS
Tree guards are used for three main reasons:
1)As protection against differing climatic conditions such as frost or strong winds
2)As protection against grazing animals such as rabbits, sheep, cattle etc.
3)As a barrier to prevent damage by machinery, for example mowers.

What you should look for when selecting a tree guard?
1) Do you really need it?
Most plants are better off without them ie: they should establish in the conditions under which they will continue to grow.
2) Will the tree guard do the job you want it too?
eg. Wire mesh is very effective against grazing animals, but provides no protection against wind, frost etc.
If you are providing a barrier against animals, you need to consider the strength and height of the guard: cattle guards need to be very strong (eg. fencing wire or heavy gauge mesh and wooden posts or steel pickets) and tall (at least 1.8 m high); sheep guards need to be at least 1 m high (eg. steel or plastic mesh); rabbit/hare guards should be at least 400 mm high.
3) How much does it cost to buy?
The cost of guards can vary from nothing (by reusing shopping bags, milk cartons etc.) to several dollars. Although some types of guards may seem expensive, they will usually provide much better protection in the long term.
4) How long will it last?
Plastic tree guards may break down within a short time if they are not made of Ultra Violet light resistant plastic. Guards which are made of durable materials can be very useful for slow growing plants, or if you intend to reuse them for other plants in subsequent seasons.
5) How easy are they to erect?
Some guards require several stakes to be knocked into the ground, others may need steel pegs.
6) Are they easy to repair or replace once established?
You should also consider how easy it is to carry out plant maintenance once the guard is in place eg. guards which are held down with steel pegs can be difficult to lift up for weeding etc.

Types of Tree Guards
#Plastic Tubes
The most durable types are UV stabilised these should last for several years. In many cases, plant growth is significantly enhanced as the tubes create a warm, moist micro climate. Protection from frost, wind, rabbits is excellent. Requires 3 4 stakes to keep the tube upright. Plastic shopping bags, old fertilizer bags etc. can also be used as a cheaper alternative, although they will not be as long lasting or effective.
#Plastic Mesh
Durable guards which are available in both flexible and rigid forms. Require pegs or stakes for support.
#Plastic pipe
Flexible plastic pipe, 50 100 mm diameter x 500 mm length, can be placed around stems of young frost sensitive plants (eg. fruit trees). These should be removed after the danger of frost has passed (fungal problems may occur, as the pipe tends to keep the stem damp).
#Wire Mesh
Chicken wire tied to stakes or stapled to 3 4 pegs provides a barrier against grazing animals. Fairly cheap and long lasting.
#Hessian
Hessian bags or cloth need to be tied around 3 stakes. Provides good wind and sun protection although they often tend to sag over time.
Should last 2 3 years.
#Tyres
Old car tyres placed around seedlings can be an effective and cheap barrier against rabbits and hares.
#Milk cartons
Useful for marking location of seedlings and providing limited protection against vermin, frost etc. Will last for 1 2 years.


TECHNIQUES FOR PLANTING SLOPED AREAS
Pocket Planting
This is simply establishing a pocket or basin on a slope, with the soil excavated from the pocket being used to form a wall enclosing the pocket, particularly on the down slope side. The wall will then retain water and help prevent soil erosion occurring. An overflow spillway in the wall will prevent the pocket from being washed away in heavy rains. The pocket may need to be reformed every now and then, until the plant is established.
This technique is usually not suitable for steep slopes.

Slope Serration
Sloping sites can be terraced to enable plant establishment and reduce erosion. Slopes are cut into steps with the steps sloping back towards the hill to retain water. Over time, the steps may erode, however, the plants will usually have become established by then. The loose soil from the eroded steps also provides favorable germination sites for seed which is dropped from other nearby plants.

Wattling
This technique relies on the use of bunches of branches placed on slopes to prevent erosion. Bundles of long, slender branches are tied into bundles and are partially buried in contoured trenches which have been cut across the slope, or cut branches and dried brush are simply spread across the surface of the slope.

In some cases, the wattling bundles have been prepared from species which root easily (eg. willows or poplars) and which then become part of the slope stabilisation scheme. This technique has been more commonly used overseas, although it can be used here on badly degraded sites to enable native species to regenerate. In Australia, dried brush is more commonly used. A similar technique is to spread a layer of straw or hay, or similar mulching material, across a sloped area and hold it in place with wire 'chicken mesh' that is securely pegged down.

PLANTING ARID SITES

Plant establishment in unirrigated, arid sites can be extremely difficult. Mulching, controlling competing weed growth, wide spacing of plants and creating saucers of soil to retain water, are simple ways of overcoming the water shortage problem. Smaller sized plants (eg: in small tubes) also have a better chance of becoming established.

Condensation traps have also been used with some success in areas with clear night skies. One simple method of trapping the moisture from condensation is to construct a 1.5 m diameter planting basin with a depth of 30 cm. The plant is placed on a mound in the centre and polythene sheeting is arranged to absorb evaporating soil moisture.

Direct Seeding
Direct seeding is a low cost method of re establishing vegetation, although the results are less predictable than transplanting established nursery grown plants.

The most important factor is to eliminate weed growth before seeding to remove competition from the germinating seeds. An initial spray with chemical herbicides will give the best results; alternatively cultivation can be used to encourage dormant weed seeds to germinate which can then be sprayed. A light cultivation of the soil will also provide favorable germination conditions for the seed. Seed can then be broadcast either by hand on small sites, or by direct drilling or mechanical hoppers for larger areas. Fencing the site and follow up weed control is also be required.

In areas where there is an existing cover of native vegetation, natural regeneration can give good results. The site should be fenced off, and the weeds on the windward side of the tree (where seeds are most likely to drop) should be removed.


Spray Seeding
Spray seeding is a technique which is often used on sites which are steeply sloped or have limited access. Seeds are mixed into a slurry of water and wood cellulose materials (ie. paper, wood shavings, sawdust etc). Using a pump, the mixture is then sprayed onto the surface of the ground. The slurry acts to provide a protective mulching surface for the seeds.
This method has also been used to establish lawns, particularly in new housing estates. This technique can be carried out by some of the larger commercial landscaping firms and by specialist spray seeders.

 


Sloping areas such require careful planting.
Once established though, the plants help prevent soil erosion



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