Richard Nunnally’s gardening column

Q:We moved to Chesterfield County this year from Long Island, N.Y. I have always had a vegetable garden; growing tomatoes, peppers, cucumbers, etc. I never had to fence in the garden in New York since the only animals I had to worry about were squirrels. I have seen rabbits in our yard along with the usual squirrels, birds, etc. Will I have to fence in my garden to protect it? If so, what should I use as fencing?

Answer: Rabbits are the primary critter you'll be able to deter with a fence. Normally a 2to 3-foot-tall fence will do the job. You can use a variety of materials, but I really like the look of a small picket fence surrounding a backyard garden. They are effective and add a colonial look to the yard. Deer may also be a problem in your area, but it's not practical to try to fence them out of a residential garden. Squirrels, of course, will do as they did back in Long Island. Squirrels seem to like to take one bite out of each tomato and then leave them to rot on the ground.

Q:What causes iris to change color from year to year? This year I had a single white bloom on a previously purple blooming plant.

Answer: Fading iris blooms is actually quite common. Some growers are developing varieties that are more colorfast. It seems that most of the ones that fade are normally exposed to more direct sunlight. The intensity of the sun tends to play a major role in their fading. One option would be to divide them this summer and try replanting some in a little more shade.

Q:I have a small yard and a patio on which I would like to put several containers with trees to be used as screening. The patio is on the southwest corner of the house and gets full sun all day. There is almost always a breeze, coming from the west. I am fond of Colorado blue spruce but wonder if they would do well in containers. I'm worried about the wind and the summer heat. Is there another tree you would suggest in containers for screening?

Answer: I'm not sure Colorado blue spruce would do well in containers in central Virginia. Even in the ground, they have problems with our hot dry summers. The summer sun would heat up the sides of the containers causing even more stress from our hot summer. Your local office of Virginia Cooperative Extension has access to a publication on using trees in containers. It includes a list of trees and suggestions on container sizes. The one I would suggest from their list is Nellie Stevens Holly. For a copy of the publication, you can contact your Extension office and ask for publication 430-023, "Trees for Landscape Containers and Planters."

Q:I am confused. In last week's tip you wrote that it is time to consider a light application of fertilizer to the lawn. I thought the best gardening advice from you and our Extension agents encouraged three applications in the fall and discouraged any spring application. I have made sure that I looked for crab grass preventer that had as little fertilizer as possible. Has there been a change?

Answer: Fall is the best time to do most of your lawn fertilization. However, the fertilization schedule from Cooperative Extension includes an optional treatment in May under certain circumstances. The reasoning behind a late-May application is that the lush growth period of spring is over and a light application of nitrogen at this time will provide a little boost of nitrogen to help maintain the health of the grass through the summer. If you opt to make this May application, it's important that it be only a quarterto half-pound of nitrogen per 1,000 square feet, as mentioned in the tip. Regular fall feedings are normally made at one full pound of nitrogen per 1,000.

The unusual circumstance this year is that we were in a drought last fall and many lawns did not get their normal application of fertilizer. We then had an extremely wet spring that stimulated tremendous amounts of top growth, possibly using up much or all of the nitrogen stored in the plant. Consequently, a light feeding now shouldn't cause excess growth and it should help restore the nutrients that keep grass plants healthy this summer.

By keeping perennial grasses healthy during the summer, our lawns are less likely to be taken over by summer annual weeds and grasses that will die in the fall, leaving us with a reduced ground cover and more potential for runoff next winter. A crab grass preventer with a minimal amount of nitrogen would be the ideal choice at this time to stimulate the good grass and provide a barrier for the crab grass.

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