Advice
RHS Help & Advice
Tree suckers
Many trees produce sucker growth from their root system. These may appear in borders, lawns, between paving stones or through paths where they can become a nuisance.
Some trees are naturally shallow rooting; many others may develop roots near the surface due to difficult growing conditions, such as a high water table or an impervious subsoil. This makes them more prone to suckering.
Suckers can appear after root damage resulting from digging or forking around trees, damage to surface roots during mowing, or where roots are accidentally or deliberately severed during excavations. If suckers are allowed to grow unnoticed they could, in time, develop into trees. Poplars, cherries, plums, stags-horn sumach, lilacs and false acacias are among the most troublesome garden trees, and Sorbus - especially when grafted onto hawthorn - can produce shoots at the trunk base.
Dealing with suckers
Suckers should be removed as close as possible to the point of origin on the root, scraping away soil to reach the base if necessary. Tear rather than cut away the shoot so that the majority of dormant basal buds are removed thus reducing the possibility of re-growth. In grassed areas where roots are surfacing, strip off the turf and raise the soil by 5-7.5cm (2-3in) before replacing the turf, between the months of October and February.
If sucker removal is difficult, sever the root to isolate the sucker from the parent tree and then carefully treat the sucker with either glyphosate (Roundup Tree Stump & Rootkiller or Deep Root Ultra Tree Stump & Weedkiller) or triclopyr (SBK Brushwood Killer). The health or stability of the tree may be affected if several large roots are severed. If treating many suckers that are still attached to a tree, sufficient chemical may be absorbed to cause harm to the tree. This chemical may also kill surrounding plants if used in borders or in lawns.
Removal of the tree may be the only solution when suckers are too numerous. Cut back the whole tree, remove any large suckers on the stump and then apply glyphosate (Roundup Tree Stump & Rootkiller or Deep Root Ultra Tree Stump & Weedkiller) or triclopyr (SBK Brushwood Killer) to the freshly cut surface. This helps to reduce the chance of subsequent sucker development, which can occur some distance away. Sucker production should gradually decline as the stump and root system die.
