Gardening Q&A with Richard Nunnally

Q:I have a large ring of English ivy around the base of an old cherry tree. The tree roots appear to be right on the surface of the ground. My question is if I use glyphosate to kill the ivy, will it harm my cherry tree?

Answer: It shouldn't hurt your cherry tree. Glyphosate works through the chlorophyll in plants, so it is taken in through the green leaves and translocated to the roots. Of course, you'll need to wait until spring to attempt your control.

Q:Since fall is a good time to fertilize grass, is it also a good time to fertilize a redbud tree?

Answer: Fall is a great time to feed trees. Now that they have dropped their leaves, the roots will store the fertilizer for use next spring. The best way to feed a tree is by root feeding. You can bore holes in the ground around the drip line of your tree and put the fertilizer in the holes or you can have an arborist fertilize them for you.

Q:What can I do to speed up my compost pile?

Answer: How fast you get compost is dependent upon how quickly the bacterium in your pile grows. It's the beneficial bacteria that causes your organic materials to decompose. Adding nitrogen is one way to speed up the growth of the bacteria. Sprinkle a little nitrate of soda in your pile to add a quick-acting form of nitrogen. Most garden centers carry small bags of nitrate of soda.

Unfortunately, the cooler temperatures of winter will slow down the rate of decomposition. However, you can keep the decomposition going by turning your pile at least once a week. This will keep the bacteria distributed throughout the organic matter and prevent portions of the pile from drying out. Once spring arrives, your composting should speed up.

Q:My neighbor recently cut several oak trees down and had the smaller limbs and twigs chipped up. Can we spread a light layer of these chips around mature dogwoods and Japanese maples as mulch?

Answer: Fresh wood chips contain a high amount of moisture and should be air dried before using around the base of plants. If you can turn the pile of chips several times over the next four to six weeks, they should be fine to apply as a thin mulch. Just be sure you don't pile them against the trunks of the trees. Even well-aged mulch can damage trees by trapping moisture against the trunk. It also provides a great place for insects to hide, which could lead to problems later.

Q:I read your recent column about an oakleaf hydrangea. Is there a difference between this and a plain old hydrangea bush? I have two hydrangeas that have become way too big. If I wait until after they bloom, how much can I trim them, and can I train the bush to not grow so big?

Answer: Oakleaf hydrangea is a specific species and there are many cultivars, or varieties. The leaves are shaped like oak leaves. They can grow in less sunlight than the standard hydrangea and have great blooms. There is a variety called 'Pee Wee' that grows about 3 feet tall and 3 feet wide. It might be just what you're looking for.

As for your existing hydrangeas, you can prune them as soon as they finish blooming. At that time you could trim them back by a third of their size. Unfortunately, there isn't a way to make your standard varieties smaller.

Richard Nunnally is a freelance writer and host of WCVE's monthly gardening show, "Virginia Home Grown." He can be contacted at .