Why is my tree sending up shoots from the roots and base?

Most garden trees, and virtually all fruit trees and ornamental cherries, are two plants: a chosen variety grafted onto a rootstock selected for vigour, size and soil tolerance. Anything growing from below the graft is the rootstock, not the tree you chose, and if it is allowed to grow it out-competes the variety above. Recognising the graft union — a swelling or a kink low on the stem — is the first skill here.

What you'll need

• Gloves
• Secateurs (optional)
• A spade or trowel (optional)

Step by step

1. Find the graft union.Look low on the trunk for a change in bark texture, a swelling, or a distinct kink, usually within 150 to 300mm of the ground on a fruit tree and sometimes higher on ornamentals. Everything below it is rootstock.
2. Identify which of the three you have.Shoots from the roots or the trunk below the graft are rootstock suckers. Vigorous vertical shoots from the trunk or main branches above the graft are water shoots, usually a response to hard pruning or stress. Shoots appearing metres away in the lawn are root suckers from a species that naturally does it.
3. Remove rootstock suckers as soon as they appear.They grow faster than the grafted variety because the rootstock has the whole root system behind them. Left alone for two or three years they take over completely, and the tree reverts to whatever the rootstock is — usually something vigorous and not worth having.
4. Pull, do not cut, where you can.Trace the sucker to its point of origin, scrape the soil back if it comes from a root, and tear it off downwards with a gloved hand. Tearing takes the dormant buds at the base with it; a clean secateur cut leaves them and you get three shoots next year instead of one.
5. Deal with water shoots differently.Water shoots above the graft are the tree's response to losing crown — hard pruning, topping, storm damage or root stress. Rub them off while they are soft in early summer, and address the cause: less severe pruning next time, or investigate the stress.
6. Investigate stress if suckering is sudden and heavy.A tree that suddenly throws suckers from the base often has a root problem, a damaged trunk, drought stress, or has been cut back hard. Look at the base for damage from a mower or strimmer, which is one of the commonest causes.
7. Accept that some species just do it.Ornamental cherries, plums, poplars, lilacs, sumach, robinia and elm sucker from the roots as a matter of habit, sometimes many metres from the trunk and through lawns and borders. This is not a fault to be cured; it is a maintenance commitment.
8. Mow or cut lawn suckers repeatedly.Suckers coming up in a lawn are kept in check by mowing. In borders, cutting or pulling them every time they appear through a growing season is the only workable method. Weedkiller applied to a sucker travels back to the parent tree's roots and can damage or kill it.
9. Do not sever the connecting root as a shortcut.Cutting the root a sucker comes from removes part of the tree's root system and often stimulates more suckering along the severed root. Deal with the shoots, not the root.
10. Protect the trunk base to stop it recurring.Mulch a clear circle around the trunk, keeping mulch off the bark, and never mow or strim up to the trunk. Bark damage at ground level is a common trigger for basal suckering as well as a route for decay.

Tips

• On a grafted tree, learn where the union is and check below it twice a year. Two minutes in spring and autumn prevents the whole problem.
• Suckers have different leaves from the variety above — often thornier, more vigorous and a different shape. That difference is the clue that they are rootstock.
• Never use a weedkiller on suckers connected to a tree you want to keep. It is translocated straight back into the tree.

Common mistakes

• Cutting suckers off at ground level with secateurs — It leaves the dormant buds at the base and stimulates them. Tearing them off at the point of origin removes those buds and gives far better control.
• Letting rootstock suckers grow because they look healthy — They are healthy — that is the problem. The rootstock is chosen for vigour and will out-grow and eventually replace the variety you bought.
• Spraying suckers with weedkiller — They are physically connected to the tree, so the chemical travels back into it. This kills more garden trees than most pests.
• Strimming around the trunk — Repeated bark damage at ground level triggers suckering, admits decay, and girdles and kills trees. It is one of the most common causes of garden tree death.

If it doesn't work

Questions people ask