Overwintered dipladenia should bloom soon
Q: I kept my dipladenia indoors over winter, and as you said it would, it dropped many leaves but overall remained healthy. I repotted it in May and the plant looks great with healthy leaves but no flowers yet. Is this typical or should I be adding anything to boost flower production? I use Miracle-Gro weekly. — Nicole Welsch.
A: Although there are different fertilizer formulations tweaked especially for flowering plants, I've always simply used the basic Miracle-Gro all-purpose type for feeding everything from African violets to tomatoes, and feel it works very well. Regular fertilizing is important for supplying the nutrition needed for flowering, so keep up the good work of weekly feedings, and your dipladenia should start blooming soon. We'd all enjoy a photo when it's in full bloom.
Dipladenia and its close relative mandevilla usually winter indoors quite successfully if you have a full-sun window and if you monitor closely for insects. Both are prone to attacks indoors by aphids and spider mites. Applying a systemic insecticide to the potting soil in autumn when the plant moves indoors helps greatly.
Q: I have two large peony plants on the south side of my house, one white and the other rose colored. They are quite old plants. The last few years when they start to flower, the buds turn brown and when the flower opens, the edges are all brown. They used to be such a pretty white and rose color. What happened to them and what can I do to get rid of the brown? — Dorothy Tretter, Hope, N.D.
A: There are two possibilities. First, peonies can remain in the same place for many, many years, with no need to dig and divide. But if they no longer flower nicely, as they once did, then dividing in September can improve health. Most old peonies can be divided into at least four sections, sometimes more. When replanting, locate the uppermost "eye," which are the buds located in the roots, at about 1.5 inches below soil surface. Planting too deeply interferes with flowering.
A second possibility of bud and flower browning is peony blight, caused by fungi. In spring, when plants reach about 12 inches in height, spray or drench the plant with an all-purpose fungicide containing the active ingredient chlorothalonil. Repeat following label directions. Although most perennials winter best with their tops left intact, peonies are an exception. Because their tops can be sources of fungal infection, cut peonies down to several inches above ground level after several fall frosts.
Q: My lawn has become mostly wild violets. I tried the new lawn-safe Roundup and am very disappointed. It works no better than Weed-B-Gon on dandelions and does not kill violets or creeping Charlie. — Lynn Tkachuk, Moorhead.
A: Wild violets, with their heart-shaped leaves and lavender flowers, are a very persistent perennial weed, and multiple sprays over several years is usually necessary for control. Triclopyr is the active ingredient recommended by Purdue University and others as having the greatest effect on violets, so search the product labels.
Spray the product following label directions in May and June, and again in September, which is the most important application of all. In autumn, weeds carry the chemical down into their roots as they're storing other material for their winter survival.
If you have a gardening or lawn care question, email Don Kinzler at ForumGrowingTogether@hotmail.com. All questions will be answered, and those with broad appeal may be published, so please include your name, city and state for appropriate advice.