Planting a Tree
You will need:
- Your tree of choice
- Garden spade
- Garden fork
- Tree stake
- Tree tie
- Hammer or mallet
- Mulch (if using)
Soak bare-rooted and container-grown trees for about 30 minutes prior to planting by immersing the roots or root-ball in a bucket of water.
Cut away the grass layer, if present. Dig a planting hole as deep as the root-ball and at least two to three times the diameter of the root system. For bareroot trees, the roots should sit easily into the hole with no roots curling around. Contrary to common advice, do not add fertiliser or organic material to the planting hole. Loosen the soil around the base and sides of the hole with a fork.
Staking is not always necessary at planting time but if using a stake, position it just off-centre in the planting hole and hammer it into place before the tree is planted to prevent damage to the roots. Make sure the stake is straight and is fixed deep and firmly in the soil. Your stake should always be positioned on the prevailing wind side of the tree so that the tree is blown away from the stake.
Remove the tree from its protective wrapping or pot, tease out the roots if necessary, and place it in the hole, next to the stake. Make sure the tree is straight and position it so that the point where the roots meet the trunk is level with the soil surface when planting is complete. Use a cane or the handle of your spade laid flat across the hole to check this, adding or removing soil so it sits at the right depth.
Refill the excavated soil from the hole back in around the root-ball or roots, shaking the tree a little to help the soil settle around bare roots. Don’t add organic matter or fertiliser to the backfill. If you garden on poor soil, you can incorporate a sprinkling of mycorrhizal fungi which form associations with plant roots and help them extract and absorb minerals and water from the soil.
Firm the backfill down in stages by lighting treading over the soil, ensuring there is good contact between the roots and the soil. This will prevent any air pockets. Avoid compacting the soil into a hard mass.
Attach the tree to the stake using an adjustable tree tie. Position the tree tie close to the top of the stake, looping it around the stake and then around the tree in a figure of '8', making sure it is not too tight. Hammer a nail with a head through the tree tie into the stake, to ensure the tie stays in position.
Finish off by watering well. Add a 5-8cm layer of mulch but leave a 10cm mulch-free collar around base of stem. Mulching helps keep down weeds and retention of soil moisture. If rabbits, hares or deer are a problem in your area, use a tree guard or spiral to protect the bark from being nibbled and damaged.
Taking good care of a tree after planting is the difference between the success or failure of the tree to establish.
Regular watering should be carried out during the first two growing seasons after planting. There is often a particularly dry period during April, May and June, and many newly planted trees die during this time from drought stress. Water deeply rather than little and often. This pushes the water deeper in the soil, encouraging deeper rooting and making the tree more drought-resistant. Sinking a piece of pipe, perforated with holes, into the planting pit will help take water down to the roots.
Weeding and mulching
Keep a circle at least 1 metre in diameter around the plant free of vegetation for its first three years to ensure water goes to the tree roots, not to weeds or lawn. Applying a layer of mulch over the surface will help smother weeds. Make sure to leave a 10cm ring around the stem clear of mulch to avoid rotting the trunk.
Don’t feed the tree during the first season. If soil is poor or a boost to growth is required, you can use a general fertiliser during the second year. However, this should not be done if you have applied mycorrhizal fungi, as the phosphorous levels found in general fertilisers can suppress the fungus.
While many trees will naturally form their adult shape as they grow, some young trees need pruning to develop a good structure as a mature tree. This may involve shortening or removing any competing leaders. Lower side shoots may also need removing in stages over the first few years if a clear trunk is desirable.
Adjust ties and remove stake
Check the tree ties every spring and autumn and loosen as needed to prevent constriction of the stem. Following bad weather, check for abrasion and snapped stakes or ties. After two or three growing seasons the tree should have made sufficient root growth to provide stable anchorage and the stake can be removed.
Tips for success
- When choosing a tree for your garden, find out it’s mature height and spread to ensure it won’t outgrow the available space. Check also that it suits your garden’s soil type and level of exposure to sun and wind.
- Container-grown trees can be planted all year round, as long as sufficient water is available, but the best time to plant a tree is between October and April. Bare-root trees must be planted while dormant, between November and March.
- Pick a healthy plant — avoid container-grown trees with pot-bound root systems. If buying a bare-root tree, make sure the roots are well-developed and that they haven’t been allowed to dry out.
- Generally speaking, the younger the tree the more easily it will establish.
- Studies show that trees develop stronger trunks and roots if they are not staked. However, staking may be required on windy, exposed sites or when planting trees that are top-grafted, bare-rooted or have flexible stems.
- A single, upright stake beside the tree, as pictured, is the standard method for staking bare-root trees. The standard method for staking container-grown trees is to insert two stakes opposite each other, outside the rootball, with a flat, timber crossbar nailed between them. The tree is secured by a tie to the crossbar. This method is also useful on windy sites.
- For most trees, the stake should be one-third of the height of the tree. For trees with long or flexible stems, as pictured, use a longer stake, cutting it lower in the second year.
- Contemporary research indicates that you should not amend the backfill soil with fertiliser or organic matter. Leaving the backfill unaltered aids quicker establishment of a more stable root system as the roots are encouraged to spread out beyond the planting hole in search of nutrients and water.