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TREE PLANTING AND AFTERCARE
This is a big subject so I can only deal with the areas that I have personal experience of
or have observed myself.
Generally speaking it is best to plant small trees (whips, 15cm to 70cm tall.) These are
easier to handle and plant and tend not to suffer as much of a setback in growth as larger
trees. Often a small whip, well planted, will catch up a larger standard tree planted at
the same time. Whips are also of course much cheaper and easier to stake and protect.
The simplest way to buy trees is from a wholesale nursery as bare-rooted plants or in plugs
that have been grown in root-trainers. Bare-rooted trees can simply be planted into a slot
or cross cut into the ground with a spade. The ground is then firmed around them and the
tree staked and protected from herbivores with a tree guard. Care must be taken with
bare-rooted trees to prevent the roots drying out during planting. Root-trainer trees have
a plug of soil in which the roots are growing. These are also simply placed into a small
hole or slot and firmed in.
Trees need protecting from herbivores. These are rabbits, voles or deer or perhaps
domestic livestock. For the wild herbivores the commonest protection is a tree shelter.
These are plastic tubes that slide over the tree and are tied to a stake. Put the stake in
up-wind of the tree and ensure that the curved edge of the tube is at the top to prevent
chafing. Also ensure that the top of the stake is driven in below the top of the tube for
the same reason.
For voles or rabbits the normal tube of 60cm or so is adequate but if deer are present a
taller one is needed. For large areas that can be fenced easily, this may be an option to
protect trees and this is the only option if domestic livestock are present.
Apart from protecting from herbivores tubes also create a beneficial microclimate around
the tree of higher humidity and temperature. Most trees grow faster in this environment
but some suffer in tubes. Horse chestnut seems consistently to get mildew and often dies
(and will in any case be subsequently attacked by grey squirrels) and hedgerow plants like
hawthorn and holly often shoot up and then bush out, only to fall over once the tubes are
removed. Plant these in wide hedge guards or with tree spirals that simply coil round the
main stem.
Try not to plant straight into grass. Ideally take a square of turf out where you plant
the tree and mulch with bark or a geotextile to prevent grass growing around the base of
the tree and competing for water and nutrients. A tree growing in grass will be only a
third as high as one mulched or away from grass after three or four years!
Trees can be planted out between November and March, i.e. when they are dormant. Don't
plant into waterlogged soil, and soil frozen to any significant depth is impossible to deal
with. Often trees are planted at 1m to 3m spacings and thinned out later.
In general it is better to plant trees in groups rather than randomly in a block. Five or
six of one species might form just such a group. If possible plant woodland trees in the
centre of a plantation with hedgerow species on the edge. These will warm the wood up by
creating a barrier to wind. Aim for diversity and try not to plant in a uniform way or in
long straight lines.
If you are planting larger, standard trees then they will come in a pot or root-balled.
These need a larger stake and guard. If the roots are spiralling in the pot, tease some
out to prevent future root growth following the same pattern. Ideally try not to drive
the stake through the root-ball! Two stakes with a backboard help to avoid this. Somehow
you need to prevent the tree from being strimmed subsequently if they are planted in grassy
areas. Mulching for 50cm either side of the trunk may achieve this.
In terms of species it depends on whether you are going for ornamental or
locally native trees and shrubs for
wildlife value. The latter would consist of oak, sessile if available, since this species
is more frost and wind resistant than pedunculate oak. The exception to this is in heavy
clay soils or very wet ones where pedunculate oak does better; ash - very good as an old
tree for cavities for owls, jackdaws etc; willow -
fast growth and second only to oak for insect species; alder - particularly in wet areas
and very fast growing; Scots pine - not really appropriate for the Lothians but a beautiful
tree; bird cherry or wild cherry - fast-growing and birds love the fruit; silver or downy
birch - the latter prefers wetter areas; aspen - grows very fast and spreads by suckering;
rowan - a smaller tree with fruit for the birds; "hedgerow" species: hawthorn - very good
for the berries but also large numbers of insects; blackthorn - similar but suckers freely;
hazel, holly. Some British trees not native in the Edinburgh area have been commonly planted.
Beech, yew and lime are good examples of species that are not locally native, but
nevertheless thrive and are of value to wildlife. Sycamore and sweet chestnut are two
European species that do well in Edinburgh. Sycamore is particularly abundant and the
largest and finest specimens in Britain are mostly to be found in SE Scotland.
Most of these can be grown from seed relatively easily.
For ornamental species the range is almost endless and of course includes many pines and
firs.
The most important point to remember is to get out there and do it. Natural regeneration
in the Lothians is a relatively rare thing and lots of human activities end up with trees
being destroyed.
Aftercare
Apart from trying to prevent trees being vandalised or ring-barked by strimmers, the main
aim for the first two or three years is to prevent trees from being swamped by nearby
vegetation.
Mulching helps enormously and also increases the availability of water and nutrients.
Vegetation can be cut back with billhooks or strimmers (careful) or sprayed with a contact
herbicide. Try and put dead vegetation back round the tree as a mulch, but avoid using lawn
cuttings as these will form a dense decomposing mat that will damage the tree.
Check ties to ensure that they are not rubbing the tree and of course, replace stakes and
tubes that are lost through vandalism. The other reason to check your trees is to replace
those that die, as some will always do. After three to five years the plants will be big
enough to remove the stake and tube and you can move on to your next patch of trees!
Nick Benge
Tree Warden, Cramond Association
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