Robin Gale-Baker, from Sustainable Macleod, discusses how to deal with fruit tree suckers.This is one of a series of articles she has written about growing fruit trees (see right hand sidebar). She has also written a number of articles about growing various vegetables, growing various herbs and general growing techniques.
For the health of fruit trees, it is important to remove suckers at pruning time. Suckers are the shoots that grow from the rootstock beneath the graft on fruit trees. Most fruit trees are grafted, sometimes having several grafts on the one tree. The rootstock is a different variety of tree than the graft and will not produce the same fruit. The graft will appear as a bulge low down on the trunk – usually around 20cm from the ground.
There are four main reasons to remove suckers:
- Suckers detract from the vigour of the tree, reducing flowering and fruiting.
- Suckers can outgrow the main trunk and make it difficult to distinguish the trunk from the sucker(s).
- Suckers can overwhelm the tree, creating multiple unwanted trunks.
- Suckers are often thorny and pose a danger of injury when you are pruning including puncture wounds from brushing against them, removing them or stepping on pruned branches. Pruned branches should be collected and disposed of straight away as they can easily penetrate footwear or wheelbarrow or car tyres.
Sometimes suckers grow from the trunk and, at other times, they grow directly from the roots. To remove them from the trunk, it is important to make a clean cut, as close to the point they emerge as possible. To remove them from the roots, scrape back the soil and try to locate the root from which they are growing and cut at the junction between the root and sucker, then replace the soil.
Do not leave a stub. Stubs create branching which is the equivalent of a heading cut where multiple shoots emerge from a single cut.
The best time to prune suckers out is when they are young & thin and it is possible to get your secateurs ‘in’ – right next to the trunk or root. The bigger the sucker is in diameter, the harder this is to do and you may need to resort to using a pruning saw or choppers. Unlike pruning tree branches, it is often awkward to get a good angle on suckers because they are emerging from the ground or the trunk low down. They can also grow very close to the main trunk, if not right up against it.
The other thing to look for is suckers growing some way from the trunk. These will be suckers from the roots and must be removed.
Suckers must be dealt with annually but check every few months and remove any re-growth. Some trees may be relatively easy to keep sucker free while others are so vigorous that it’s a constant job.