Catalpa
Leaf spots (fungi)
and spot anthracnose (fungi)
Round to irregular, yellowish-brown to black spots. Spots may drop out, leaving
holes. Collect and remove fallen leaves. No chemical control is suggested under
most conditions.
Powdery mildew
(fungus)
Powdery white patches on leaves. If severe, leaves may drop early. Remove and
destroy fallen leaves. If serious, use thiophanate-methyl. Make first application
at bud breakand the second 10 to 14 days later. Under wet conditions, apply a
third spray 10 to 14 days later.
Verticillum
wilt (fungus)
Leaves on one or more branches wilt, turn brown, bend downward and drop early. Purple to blueish-brown streaks in sapwood under bark.
Cut, remove severely affected trees. If only 1-6 dead or wilted limbs, prune
affected parts. Dip pruning tools in 70 percent alcolhol or 10 percent houshold
bleach between cuts. No chemical control suggested. Cultivars vary in susceptibility.
Updated 6/8/09