Troubleshooting
Downy Painted Cup problems — and how to fix them
Downy Painted Cup (Castilleja sessiliflora) is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Host dependency failure
Without an established host grass or forb in the root zone, plants yellow and decline rapidly. Sow seed in direct contact with roots of native grasses such as hairy grama or June grass — do not plant into bare, sterile ground.
Root and crown rot
The single most common cause of failure in cultivation; any soil that stays moist after rain causes rot at the root crown. Ensure very sharp drainage and avoid summer irrigation once plants are established.
Prevent downy painted cup problems before they start
Most downy painted cup issues are care-mismatch, not bad luck. Dial in the basics:
Downy Painted Cup problems — FAQ
Why is my downy painted cup host dependency failure?
Without an established host grass or forb in the root zone, plants yellow and decline rapidly. Sow seed in direct contact with roots of native grasses such as hairy grama or June grass — do not plant into bare, sterile ground.
Why is my downy painted cup root and crown rot?
The single most common cause of failure in cultivation; any soil that stays moist after rain causes rot at the root crown. Ensure very sharp drainage and avoid summer irrigation once plants are established.