How to Manage Pests
Pests in Gardens and Landscapes
Phytophthora root rot on cole crops—Phytophthora megasperma
The external surfaces and internal tissues of roots infected with Phytophthora are dark in color
and are rotted. Leaves, especially older ones, turn purple red and wilt. With time the entire plant wilts.
The stem near the soil line may turn black and become soft.
Phytophthora root rot usually occurs only if cole crops are planted in poorly drained, fine-textured
soils that are kept overly wet. Prepare soil so that low spots are minimized. High, well-draining beds
will discourage disease development. Irrigation should be carefully monitored to avoid excessively wet
soil conditions. Be careful not to stress plants with underwatering; ensure an even supply of moisture
to help suppress disease development.
For more information, see the Phytophthora
Root and Crown Rot Pest Note.
sprouts infected with Phytophthora