Newly planted plants and those under stress are most vulnerable to infection. The Symptoms One type of wilt progresses slowly causing yellow-green foliage, marginal browning of leaves, stunted growth, smaller than normal leaves and shoot dieback. A second type causes severe symptoms such as shriveled leaves, early fall color, loss of foliage, and dieback of branches or entire plants. Affected branches may show green-brown streaking of the sapwood. What To Do Vigorously growing plants can often compartmentalize the infection within a few branches.
Water plants weekly during hot, dry, periods.
Maintain adequate nutrient levels with a balanced fertilizer if needed. Prune dead or dying branches to maintain appearance of affected plants. Available fungicides show only inconsistent results, but research proceeds. Spores are spread by rain splash and wind , and infect emerging leaves and succulent shoots during cool, wet conditions. The cycle can repeat itself as long as conditions remain wet.