“Groundwork” column for Sept. 27, 2013

Got problems with your oak, brown leaves on you Japanese magnolia or blueberries in need of transplanting? Here’s some advice from the LSU AgCenter expert.

My oak tree is covered with hundreds of round balls. They first appeared last year but were only a few. This year it is on almost every branch of the tree. What is it and how do I control?

The galls are caused by cynipid wasps laying eggs in the tree. Once spring growth initiates, the eggs hatch and the feeding activity of the larva cause these balls to form.

Treatment is difficult and seldom necessary, but if so desired the foliage must be sprayed just as it begins to emerge in early spring. The use of systemic and residual materials early at bud break is suggested to prevent infestations. Sprays should be repeated at monthly intervals for three to four months.

Our Japanese magnolias have some brown/burnt leaves. The remainder have a light white powder on the upper side.

I think you may be describing one or two different problems. The brown/burnt leaves could easily be attributed to extreme summer temperatures and/or drought conditions.

The light white powder could be a result of this or it could be a disease called powdery mildew. I wouldn’t expect mildew to be a problem this time of year, but it is a possibility. Trees are sensitive to poorly drained and overwatered soils. Also look for basal damage from string trimmers.

Positive ID is best. I suggest submitting a sample to the LSU Plant Diagnostic Clinic on the LSU campus.

I have several small blueberry bushes that have been in the ground three or four years, but not growing much because I know they aren’t getting enough sun. I want to transplant them and am wondering what would be the best time. Also, anything else I should know about actually moving them?

The best time to transplant would be during the fall and winter months. Prepare a raised bed 8-12 inches high. Incorporate organic matter and supply water. Space plants 6-8 feet apart. Try to retain as many roots as possible — they will be mostly in the top 4-6 inches of soil. Do not fertilize. Keep moist but not wet and mulch.

Got a gardening question? Write to Bob Souvestre, horticulturist with the LSU AgCenter, at Burden Center, 4560 Essen Lane, Baton Rouge, LA 70809, or email to bsouvestre@agcenter.lsu.edu, or call Master Gardeners at (225) 763-3990.