This covers the first five years after planting.
Weed control
A square metre of bare ground should be maintained around each young tree. This can be done by using a herbicide, mulch mat or loose mulch material.
Replacement of failed plants
Some losses will be inevitable, and the planting density will have allowed for this. Up to 10% losses may be acceptable. If losses are higher than this, you will need to find out why this has happened, rather than risk replanting only to have more failures. With drought an increasing problem in the British Isles, note those species which have survived, and plant more of those, rather than replanting the species that have failed. Choose other species from those which are adapted to light, free-draining soils. Use a polythene sheet mulch covered with a layer about 150mm thick of loose mulch material around each tree, to keep the rooting area cool and damp.
Where many trees have failed in spite of sufficient rain, there may be a problem with nutrient deficiency or soil contamination. The soil or substrate should be analysed and specialist advice obtained.
Where failure is due to vandalism, trampling, grazing or damage by rabbits, voles or deer, action will be needed to protect from further damage before replanting is done.
Casual vandalism may lessen as the trees become familiar and less inviting objects to vandalise. Providing some other sacrificial target may divert the vandals. Deliberate destruction of the trees may indicate a more serious problem of members of the community being against the project. Further consultation and possible amendment of the planting plans may make the project more acceptable. Trampling that indicates a particular desire line through a planting plot should be allowed to develop into a path, with improvements to it as necessary. Don’t replant or try to fence across a desire line.
Rabbit damage can be stopped by using spiral rabbit guards. Voles use the cover of long grass or mulch materials to reach the young trees, so where they are a problem, use a herbicide instead to keep a bare patch around each tree. Livestock and deer can only be prevented damaging trees by fencing or individual tree protection.
For advice on pruning, see here.
Ground treatment of area between trees
In a tree planting plot with 1.5m spacings between the trees, 75% of the ground will be outside the weed-free spots, and may require management. The long-term aim should be to create a typical woodland flora of shade- tolerant plants, but this cannot be established until the woodland canopy has begun to close.
The easiest sites to manage are those with poor, stony substrates. These are not able to support lush growth of grasses, and may need no treatment. If brambles, docks, thistles, hogweed or similar tall plants become established, they will need removal or herbicide treatment to prevent them restricting the growth of the young trees. Docks, thistles or hogweed should be cut down before they seed. Brambles should be cut down, and the roots dug out if possible. It should be possible to leave the cut material on site to rot down and form a mulch around the trees. nettles can be an advantage in deterring access, but may need cutting if they overtop the young trees.
Fertile sites with deep soil are more difficult to manage, because of the lush growth they can support. On grassland sites, it may be worth stripping off the turf before planting, and either using it elsewhere, or stacking it to rot down for garden use or resale. This is hard work by hand, but may be worthwhile in the long run in removing the grasses and topsoil to reduce competition, and in reducing fertility in the system. If complete clearance of the turf isn’t possible, strip patches of at least 10 sq. metres each, scattered through the site. Creating humps and hollows in the site will create bare ground and damp patches, encouraging a more diverse ground flora.
Mowing the turf between trees is usually the least successful option, as well as being time-consuming. Machine damage to the young trees is likely, the grasses are merely stimulated to grow thicker and lusher, and the young trees are very noticeable, especially to potential vandals. It’s usually best just to leave the grass to grow, making sure that the weed free spot around each tree is kept clear. Long, dry grass may be a fire risk in summer. Where ‘torching’ is a local pastime, the grass may need to be cut and removed, especially where there is a risk of a fire spreading to adjacent property. However, a rapid grass fire does not usually permanently damage young trees, and may even do some good by removing the competing vegetation.
Selective herbicides which only kill grasses can be used to encourage the growth of the more interesting perennial and annual flowering plants. This should be done by a qualified operator using an approved herbicide.
Any techniques which reduce the grassland species and ranker weeds will both help the trees to establish faster, and produce conditions which are more conducive to the ingress of woodland plants. A mulch of woody material
spread as thickly as possible will smother some of the unwanted growth, and produce conditions similar to a natural woodland floor. The rotting material will attract invertebrates and micro-organisms which help develop the woodland ecology. During the first five years, bring into the developing woodland surplus woody material from elsewhere. Where ‘torching’ is not a problem, logs and large branches can be simply put down where they will not hinder access, some scattered, some piled up. Smaller branches should be put through a wood chipper, and the resulting mulch spread at least 100mm thick. Concentrate first on those areas where the young trees are growing fastest and the canopy beginning to close. Spreading a mulch very thinly over a larger area will have little effect.
