Gerry Daly What to do in the garden right now
AN UNMISSABLE GUIDE TO WHAT YOU CAN DO IN YOUR GARDEN RIGHT NOW BY IRELAND’S LEADING EXPERT
IT’S the best time to plant a tree: but do you plant a tree, and should you buy one bare root or in a pot? And what tree should you choose? Size also matters in this regard, as some trees are better suited to a small, medium or large garden. So these questions require some thought and hopefully the answers lie here. The dormant season is just beginning and this is the best time to plant trees because the leaves are off the branches and the plant is under less stress from drought.
Instead, it has several months when the soil is moist to get itself re-established.
Tree planting is very simple. Somewhere in the distant past, somebody pulled up a sapling and began to wonder whether it could be grown somewhere else. That is the essence of planting trees to this day. Yet many trees fail every year because their basic needs are not met. This mostly has to do with lack of water or surplus water, or overly deep planting – a very common error.
The development of plastic pots has made tree planting even more successful and not strictly limited to the traditional planting season, October to March.
There are various ways to group trees for reference. Some are termed garden trees and usually they are colourful and flower, such as flowering cherry, flowering crabapple, magnolia, laburnum, Japanese maple, hoheria, hamamelis and parrotia.
There are very few trees grown for their show of autumn colour, such as parrotia, Japanese maple, Clerodendrum, liquid amber and tulip tree. The latter has tulip-shaped flowers but these are barely visible among the new, lightgreen leaves, the flowers of tulip shape being yellow and hanging upside down.
Another group are trees planted as groups or lines to provide shelter and privacy, two major bonuses of having trees.
These trees are likely to be less decorative, and less exotic, than the shelter or garden woodland trees. These typically include species such as birch, ash, hornbeam, alder, hazel, hawthorn, pine, evergreen oak, wild cherry, yew, wild crabapple, grey willow and goat willow, not to mention ivy that scrambles up so many trees, and can cover a sizeable tree after about 10 or more years. These are mostly native species, or at least naturalised ones, such as beech, sycamore, Norway maple, field maple, walnut, horse chestnut and sweet chestnut.
CHOOSING THE RIGHT TREE
The beech is an introduced tree, from southern Europe, that is now traditional and part of the landscape, so that it does not look foreign.
It is good as single trees and groups, and makes fine woodland. It must not be grown on wet ground or land with a high water table.
Hornbeam is like beech but can do much better in wet soils. Sweet chestnut is a big tree, like oak i n man y wa y s , wi t h fine structure, excellent timber and is very long-lived.
It makes a good specimen or group. It can have a tendency to lose branches when it grows too rapidly on very good land.
The sycamore is so widely grown and self-sown that it appears native but it is not. It is a very good tree for windy places and can be grown in a cluster or on its own. It has good timber and lasts well.
The Norway maple is a very fine tree, somewhat like its sycamore relative. It grows very well in good soil.
White willow and poplar, meanwhile, are good trees for wet ground. Both are fast growers, and have soft timber and both are not long-lived.
Of the evergreens, holly is native and can make a big tree if allowed to do so, it is a great tree to mix in with others, at the rate of 5% or 10%.
The best conifer for general decorative planting is the Scots pine, arguably a native tree. It is sturdy, very wind-resistant, quite long-lived and easy to grow but not in wet soil.
If you are thinking of laying down some trees, there are a few things to bear in mind.
Start off by identifying areas where trees might be planted. There are corners or other bits of ground in most places where a tree or trees
could safely grow. Will the area be wanted for some other purpose in the future? Will the trees be in the way of machinery, roads, power lines, water or drainage?
Trees need space and we must think of their eventual size. Will the site be able to accommodate a tree when it is 15 or 20 metres across?
It is not uncommon to see a fine 30-year-old cedar tree filling the entire space of a suburban garden and eventually such a tree is removed after a few vain attempts at restricting it by pruning.
It can be argued, of course, that the tree gave 30 years of beauty, and that’s true, but it seems a pity that the tree was not chosen well to begin with.
So it is important to match the number of trees and the kind of trees to the site.
If there is room for just one tree, then stick to planting just a single tree.
It is possible to plant a small group of the same trees, or a mixed group, and, after ten or 15 years select the best one to be the single tree remaining. The competition forces the young trees upwards and they make a taller trunk.
PLANTING AND THINNING
If an area is big enough for planting of garden woodland, a shelter block or a long shelter belt, the same approach of initial over-planting and later thinning can be applied. Plant the trees at about two metres each way. Ideally, for appearances, group planting should not be done in lines. Instead, the spacings should be random – this appears more natural. Thinning can begin at ten or 15 years and again about 20 years, reducing by a quarter to half the number of trees each time.
When planting groves of trees, it is best to have a mix of species. They can be chosen for the soil and for preference, but it’s good to have about 60-70% of one species, with a mix of two, three or four other species as the remainder.
This enhances the look of a plantation with seasonal changes.
Control all weeds before planting and plant directly into the dead sod. Keep weeds down for five years to double the rate of growth.
Plant whips of 60-90cm, depending on species. These are normally bare root, and relatively cheap to buy in quantities from forest nurseries. Dig test holes to 40cm or 50cm deep and observe them very well.