Last week I wrote about leaf gall on Camellias and azaleas, and those comments led to several more questions. Leaf gall is a very common disease that affects camellias. This disease affects Camellia sasanqua (the small leaf camellia that blooms in the fall) more than Camellia japonica (the large leaf camellia that blooms in the winter). The cool nights, overhead irrigation and rains in the early spring make this disease flourish. This disease is caused by the fungus Exobasidium camelliae. There is another Exobasidium fungus that affects azaleas in a very similar way.
Leaf gall is the common name for this fungus. The leaves become very large and fleshy. The new growth is much thicker than normal and then the leaves break apart and release spores. When the leaf breaks apart, you can see the lower part of the leaf turns white. The disease spreads by wind and splashing water. A good layer of mulch will help with the splashing water.
The best control for leaf gall is to pick the infected leaves off as soon as you see them in the spring. If you can pull them off before the spores develop, you can prevent the disease from spreading. Once you pull them off, place them in a plastic bag (the one your newspaper comes in is handy, a dog poop bag, or any other plastic bag you might have around the house) and throw them away in the garbage or burn them in the ever so popular backyard fire pit.
Usually this disease does not require chemical treatment. The manual pulling off of leaves and limiting overhead irrigation in the spring, when the nights are cool, will keep it in check. If you have a severe problem year after year, you could apply Mancozeb at bud break. This control should be your last resort, and only used in severe cases.
For this year, pull off as many infected leaves as you can. Soon your plants should go back to producing its normal size leaves. The leaves that were affected by leaf gall will soon wither, turn brown and fall off the shrub.
Fleas, large patch fungus in turf, stinkhorn fungi (devil’s backbone) in mulch, and slow to green up areas in the grass seem to be dominating the questions that I have been getting recently. Oh yeah, how to get rid of moles!
Charleston Horticultural Society’s Plantasia is coming up Friday (the 29th) and Saturday (the 30th), check their website for more details. The Rose Society’s Rose Show is coming to Citadel Mall Saturday May 7th from 1pm until 5pm. These roses will blow your mind. Exhibit your roses or just look at the displays. I’ll have to shock my teenage daughters with the first time ever question, “hey squirrels, want to go to the mall?”
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