Crown Rot
The stem right at the soil line goes dark, soft, and sunken while the top yellows and collapses — the plant is being girdled where stem meets root. Wet crowns from deep planting, piled mulch, or heavy soil are the usual invitation.
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.
1Pull mulch off the crown
Mulch to the drip line, never against stems — a bare ring of a few inches keeps the collar dry.
Try this first2Replant at the right height
Crowns set below grade rot; perennials and trees alike want the root flare visible at the surface.
3Remove the infected plant
Once the crown is soft there is no recovery; take the plant and the soil clinging to it, and improve drainage before replanting.
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Which plants get crown rot
Every plant we cover that gets crown rot, 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.
perennials12
Coral Bells (Heuchera)Heuchera hybrids
CoreopsisCoreopsis verticillatain wet clay
DelphiniumDelphinium elatum
Hellebore (Lenten Rose)Helleborus × hybridus
HostaHosta spp.
Lamb's EarStachys byzantinain humid/wet conditions — the main issue
LupineLupinus 'Russell Hybrids'in heat/wet
Pasque FlowerPulsatilla vulgarisin wet soil
Prairie SmokeGeum triflorumin wet soil
RhubarbRheum rhabarbarumin wet soil
Shasta DaisyLeucanthemum × superbum
Water LilyNymphaea hybrids
biennials3
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 Ranunculaceae, with 3 of the 21 affected plants.
- Ranunculaceae3 plants
- Asparagaceae2 plants
- Asteraceae2 plants
When to treat
There is no spray for it. Fix the planting depth and the drainage, and remove plants that have already collapsed.
Timing only — the label is the law
This page tells you when to watch for crown rot 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 rot, 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.