Q: When do you prune Encore azaleas? Sandi Grimm, Gainesville
A: This is an understandable question because reblooming azaleas (Encore, Bloom-A-Thon, etc) can have flowers on them for most of the growing season. The answer is to prune, if needed, after the first flush of flowers in spring. There’s plenty of time after that for them to form their summer buds as well as buds for the fall flowers that are so beautiful now.
Q: I planted 40 impatiens plants in a bed this past spring. The flowers did very well for most of the summer. In early fall, the plants started to drop leaves and flowers, exposing the stalks. There is a gray powder on the leaf backs. Is this downy mildew? Can I plant pansies in this bed? Tim Adkinson, Forsyth County
A: Your description exactly describes this fatal disease’s progression. Impatiens downy mildew continues to have an impact on greenhouse growers and gardeners across the country. Once a bed is infected, you can’t plant impatiens there for several years. One theory is that the process of breeding impatiens to produce lots of flowers lowered the plant’s resistance to downy mildew. It is a very specific disease, so it won’t affect your pansies at all. Remember that New Guinea impatiens, coleus, or Sunpatiens could grow in that spot next year without problems.
Q: I have a four-year-old blueberry bush I need to transplant to a new location. Is this possible? Steve Whitley, email
A: Blueberries have very fine, wide-ranging fibrous roots. This is normal for plants that have to scavenge for nutrients under trees in nature. Their root system does not grow very deep. One good way to move a blueberry plant is to rake away the mulch underneath and then soak the soil with a drip hose for several hours, making it soggy. With a spading fork you can explore where the roots run and then lift them out of the soil with your hands. When you are finished you’ll have a wide pancake of a root system. In the plant’s new home, dig a hole ten inches deep and sized to fit the root system. Mix the removed soil 1:1 with peat moss. Put the blueberry into place and cover the roots with your soil mixture. Lift the plant so the trunk is in the soil at about the same level as it was originally. Soak the roots and soil with water, add more soil mixture and level it as needed. There is no real need to add fertilizer but you can add a handful of starter fertilizer if you like. Fertilize in March with an organic product like Holly-tone or Milorganite. Your blueberry will never realize it was moved.
Q: What is the best height to mow centipede and bermuda? I generally mow them at 3 1/2 inches. David Fowler, email
A: Both centipedegrass and bermudagrass do best when mowed around 1 1/2 to 2 inches high. When you mow higher, the grass won’t grow as a densely as it should and you may have a thatch problem. The recommended height may necessitate you mowing the bermuda more than once per week. A five-day schedule is usually adequate.