Crown Gall
Rough warty swellings on roots, at the soil line, or on canes. They start pale, soft and spongy, then turn brown, hard and knobby. They are tumours the bacteria make the plant grow, so they are solid tissue rather than a rot or an insect nest.
Disease checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of it
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Inspect nursery stock
Look over the roots and crown of every plant before planting and reject anything carrying a lump.
Try this first2Do not replant the same spot
The bacteria live on in soil for years, so move new plants of the same kind well away from where a galled plant grew.
3Stop wounding plants
Keep mowers, trimmers and hoes off trunks and crowns. The bacteria only get in through wounds.
4Sanitize pruners
Dip tools in 10 percent bleach or 70 percent alcohol for 30 seconds when moving between plants.
garden pruner disinfectant5Treat at planting, not after
A biological root dip containing Agrobacterium radiobacter K84 can protect new stock on most fruit crops, though not grape, and it does nothing for a plant already galled.
agrobacterium radiobacter K846Remove the plant
Dig out badly galled brambles, roses and young trees. There is no cure for crown gall.
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Which plants get crown gall
Every plant we cover that gets crown gall, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same disease can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
trees4
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Rosaceae, with 5 of the 8 affected plants.
- Rosaceae5 plants
When to treat
Check roots and crowns before anything new goes in the ground, because no spray cures a plant once galls are on it.
Timing only — the label is the law
This page tells you when to watch for crown gall and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets crown gall, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.