Wednesday, September 20, 2006

Crape Myrtles bloom with a dose of Epsom Salts

QUESTION: “I have eleven Crape Myrtles in my front yard, Last year they flowered. This year there was limited flowering, and My white Crape Myrtle did not flower this year. What plant food can I give them to make the all bloom for next year? Can you give them spike slow release food? What would be the best, and when do I start to feed them?” – Diane Buncamper

ANSWER: There are two things to bear in mind. One: If you fertilize with a heavy nitrogen you will produce foliage but no blooms. Two: In order for your Crape Myrtle to bloom you may want to try this cocktail (for the Crape Myrtles, not you) Mixone tablespoon of Epsom Salts into one gallon of water and pour around the roots of the plant. Repeat for the others, using one gallon per plant. This works by stressing the plant causing it to bloom. I would try the Epsom Salts now and perhaps nip back the tips of the tree or even trim if it needs shaping.

QUESTION: “I just moved into a new home that has a Dogwood and it doesn't seem to be doing well. Many of the leaves are turning red. The leaves that are entirely red are shriveling up with the tips of them brown, and it looks like the tips of those leaves are dying. The other leaves have purple spots on them. Some of those have some tan spots that have dark rims but not all the leaves have this. However, all of the leaves have purple spots or blotches on them.

One section of the tree has what looks like a white residue on some of the leaves that are on the ends of the branch. Most of the leaves are not fully open. Also the bark is all green on the main trunk and there are light green, and whiteish-green blotches on the trunk and branches. There is some yellow on the trunk near the base of the tree. Its early September so some of the leaves could be changing early, but most look sick. The tree sits in full sun in the front yard. Please help! Is there anything I can do?” – Chuck Strub

ANSWER: I’m sorry to say that I don’t think there is not a whole lot that you can do. From what you tell me, one of two things is most likely happening. The first of these is that the tree has developed anthracnose and, sadly, there is no cure. It is a disease that I believe will eventually wipe out the regular native Dogwoods as we know them. Fortunately, there are new hybrids being developed that are anthracnose resistant. One successful variety is named Appalachian Spring.

The second possibility is that your tree is displaying powdery mildew which again is common to Dogwoods. You can spray with a fungicide such as Cleary about 3 times during the growing season to control that. Good luck!

QUESTION: “I enjoy your column very much and have learned a great deal from it. Now I have a problem not only with moles/gophers throughout the entire garden and yard but also white stuff that has appeared on my zucchini, other squash, phlox and even wild roses. Is this Scale? and if so, what can I use to get rid of it? I have also found it in other areas around Wisconsin. Thanks for your good columns and helpful advice.” – Janet Fassino

ANSWER: I don’t know for sure, but it just sounds like powdery mildew which is spread by wind. Since humidity encourages it, late summer with cool nights and warm days is when you are likely to see more of it. If you think that this is what the problem is, you can spray your perennial plants with the following mixture.
1 gallon water
2 ½ tbs horticultural oil
1 tbs baking soda
Mix and store in labeled closed jar. Spray as symptoms appear on into cool weather.

There isn’t much to say about moles/gophers. They are a pill to deal with! There is a product called Mole Stopper which works with the taste and smell of the critter to keep it away.

The Plant Man is here to help. Send your questions about trees, shrubs and landscaping to steve@landsteward.org and for resources and additional information, including archived columns, visit www.landsteward.org