How do I stop raspberries spreading across the garden?

A raspberry row is a colony rather than a set of individual plants. The roots run horizontally, close to the surface, and send up new canes wherever they find light and space — which is why a row planted in a border ends up in the lawn, in the path and in next door's bed within a few years. The behaviour is not a fault; it is how you propagate them, and it just needs a boundary.

Step by step

1. Remove suckers where they emerge, not where they root.Cut or snap the cane off at ground level, or pull it sideways so it tears from the root. Repeated removal exhausts the root over a season or two.
2. Do not dig them out with a fork.Digging chops the shallow roots into pieces, and every piece with a bud makes a new cane. The row typically comes back thicker afterwards.
3. Mow anything appearing in the lawn.Raspberry canes do not survive regular mowing. A sucker in a mown lawn will be dead in a season with no other effort.
4. Keep a mown or hoed strip along the row.A 30–45cm strip either side of the row, kept clear, gives you an obvious boundary and makes stray canes easy to spot and pull while they are small.
5. Install a vertical barrier if the row is next to a border.Rigid plastic root barrier, heavy damp-proof membrane or paving slabs on edge, sunk 30cm and standing slightly proud of the soil. The roots are shallow, so this genuinely works — unlike with bamboo.
6. Confine a small planting in a bed with sides.A raised bed with solid sides, or a large container, contains raspberries very effectively. Autumn varieties are particularly well suited to this.
7. Use the suckers rather than binning them.A well-rooted sucker lifted in winter is a free plant for a new row or for a neighbour. Only propagate from healthy, well-cropping, unmottled plants.
8. Clear a row you no longer want, properly.Cut everything to the ground repeatedly through a season, removing every new shoot as it appears. Exhausting the roots takes a summer; digging takes years.

Tips

• Autumn varieties tend to sucker more freely than summer ones, because the whole plant is renewed from the base every year.
• Suckers appearing several metres from the row usually mean the roots have found loose cultivated soil to travel through. Compacted ground and mown grass both slow them down.
• A raspberry sucker looks exactly like a young cane, with the same prickly stem and toothed leaves. If in doubt, follow it down and see whether it has its own crown or comes off a running root.
• Never rotavate an area with raspberries in it. You will multiply them across the whole plot.

Common mistakes

• Digging out suckers with a fork — The roots are brittle and shallow, and every broken fragment left in the ground regrows. Removing the top growth repeatedly is more effective and less work.
• Using a weedkiller near the row — The suckers are connected to the plants you want. Systemic weedkiller travels back through the root system and damages or kills the row.
• Planting raspberries in a mixed border with no boundary — They will colonise it. Give them their own strip with a clear edge, or a barrier, from the start.

Questions people ask