ArcaMax

Q: I have several red twig dogwoods that look beautiful each spring. By midsummer, they continue to grow new sprouts and otherwise appear healthy, but many of the leaves get spotty, turn yellow and fall off. Is this a fungus? Can it be cured?

A: It probably is a fungus, because shrub dogwoods are affected by many fungal diseases. Most of the leaf spot diseases are more cosmetic and not too harmful. Clean up the dead leaves as often as you can, especially in the fall. A fungicide spray may help, but it will have to be used consistently in the spring and maybe all season long.

If the stems develop black sunken areas, cut them out at the base of the plant. Sterilize the pruner with rubbing alcohol between each cut, so it does not spread the disease. Prune the shrubs so they have air circulation through and around the plant. That will help dry the leaves, which will help slow the spread of the fungal diseases.

Keep dogwood shrubs watered as they naturally grow along pond edges. Do not get a lot of water on the leaves, especially in the evening, when the fungus can infect the leaf or stem.

Q: I have a flagstone patio swept with crushed lime between the stones. Moss is growing between the bricks. I want to get rid of the moss. Can you think of something?

A: Moss grows in shady locations with compacted soils that do not drain well and have poor fertility, but usually the soil is more acidic than what crushed lime would give. There are "weed" killers at some garden centers specifically designed for moss.

I like moss between the stones myself. It softens the harshness of a large expanse of stones. Scraping it off or using a power washer will remove it for a while, but it may come back more quickly if you use these methods.

Q: We have a magnolia tree in our front yard that has developed a white mold or fungus on all the branches of the entire tree. We have two of these trees about 50 feet apart, and only one tree is affected. These trees are about four years old. This same tree started to get this mold or fungus on it last year, and I applied Sevin dust on it, but it never really helped. I thought it would die over the winter, but it bloomed this spring and now has abundant green leaves. Please help me save this tree.

A: Sevin dust is an insecticide, and the white powder is a fungus, so it won't have any effect. Look for a fungicide with a label that says it will kill powdery mildew. Follow the directions both now and next year. Check the other tree and all the other landscape plants in your yard for early signs of infection -- only a few leaves with the fungus -- and spray any infected ones, too. Do not spray them if they do not have the fungus. However, you can spray plants that do not have the fungus if they had it in the past.

Usually, powdery mildew occurs in shady areas. It can grow on lawns, vegetable plants, shrubs and trees. If possible, can you cut some tree branches to allow more light to reach the affected plants? It may not be possible, and sometimes the shade is from buildings.

========

Email questions to Jeff Rugg at info@greenerview.com. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Copyright 2025 Jeff Rugg. Distributed By Creators.