Tree Planting Guide

Choosing your Tree

Always check that your tree is UK grown. Imported stock risks pests and diseases such as Oak Processionary Moth or Ash Dieback entering the UK.

Here are some suggestions for trees you could plant that will do well in our area:

Whitebeam - Sorbus aria

Whitebeam has a soft, pale green leaf in Spring and its fruit is valuable to birds. Grows best in direct sunlight. Canopy can cast dense shade so consider placement in relation to windows and patios.

Dutch elm disease resistent elm - Ulmus 'New Horizon'

This elm provides habitat for the rare white-letter hairstreak butterfly. Needs a large free-draining garden. This is a UK Biodiversity Action Plan Priority Species.

Turkish hazel - Corylus colurna

Broad, symmetrical canopy of pleasing appearance. Best planted in open spaces or as a feature tree in a large garden. Robust tree which tolerates the rigours of urban life. The nuts are good to eat.

Fastigiate hawthorn - Crataegus monogyna 'Stricta'

Ascending branches and upright form, good for sites where space is at a premium. The late emerging white flowers signal that summer is coming, and are beneficial to pollinators. The red autumn berries are nutritious for birds and apparently make a nice jam!

Cut-leaved alder - Alnus glutinosa 'Laciniata'

Alders are typical wetland trees; you'll see them on the edge of rivers and ponds. This cultivar has interesting, deeply-lobed leaves. Particularly suitable for sites with poor soils. Alders grown as individual, solitary trees tend to have a broad, conical shape at maturity - I think that the winter silhouette of alder is the best of all trees. Be aware, pollen from this tree is thought to be a major cause of hay fever.

Selecting a Site

When selecting a site for planting, visualise how large the tree might become. Could it block a view, cast shade onto a patio or interfere with foundations? Inappropriate siting frequently results in pressure to fell or mutilate healthy trees.

When to Plant

The best time of year to plant a tree is November or December. Avoid planting during sub-zero temperatures; this can damage sensitive roots, and the ground is too hard to dig!

How to Plant

To plant your tree, you should dig a square-shaped hole to the depth of the rootball and between 1.5 and 2 times wider. Don’t break up the bottom of the hole as was once standard practice. Separate topsoil from subsoil. Don’t worry about adding organic matter, fertiliser or mycorrhizal dips. These are usually unnecessary.
Tall, top-heavy trees with no lower branches, trees in exposed locations or near heavy traffic may need staking. Drive two stakes 30cm into the pit at the width of the rootball, in line with the prevailing wind. Get these in position before planting to avoid root damage.
Lower the tree into the pit, ensuring the root flare is at ground level. Burying the root flare causes roots to grow upwards potentially causing a structural defect. Backfill with the subsoil followed by topsoil. Squash this down every so often so that it feels firm but not compacted. Fix the stem to the stakes with Hessian, but not so tight that it prevents natural movement. The aim is to stimulate stem thickening and support root development.

Once planted, you’ll need to water it immediately. For trees other than whips, this should be enough to completely soak the rootball; approximately 20L. Then spread a 10cm deep circle of composted hardwood woodchip 1m radius from the stem, leaving a mulch-free donut immediately at the base. This reduces evaporation from the soil, moderates its temperature and inhibits weeds.

Looking after your Tree

Water weekly while the tree is growing (March-early September) for at least 2 years while the root system establishes; more during hot, dry periods, particularly if the leaves are wilting. Rainfall doesn’t tend to reach the roots so you’ll need to keep watering regardless and top up the mulch.

After two years, remove the stakes as it should have developed a healthy root system, making them unnecessary.