Andy Starnes, Post-Gazette Aaron Sturges, of Sturges Orchards in Fombell, Beaver County, holds petunias. Click photo for larger image. Related article: Garden Shorts: Feather will talk about insect control

A. Petunias look great for the first few months -- especially the self-deadheading 'Wave' types. But by mid-August, it is common for them to become bare in the center, with all the foliage and flowers out at the ends of the stems.

Careful pruning can rejuvenate tired petunias. Cut about one-third of the leggy stems back to 4 or 5 inches. Once they respond with a flush of growth, cut back the second third. When those stems put on a flush of growth, cut back the final third of stems. If you cut the entire plant back so hard all at once, it would probably die. By spreading the stress out and allowing the plant to recover in between, hard pruning rejuvenates rather than killing.

It is also helpful to fertilize petunias (and most annuals) regularly during the growing season, especially when they are grown in containers. Since containers have to be watered frequently, the nutrients are leached out of them quickly.

Start by using a coated release fertilizer that will distribute nutrients over a longer period of time -- three to four months. Coated release fertilizers include products such as Osmocote or Schultz MultiCoat Time-Release Plant Food. Mix the fertilizer into the potting soil you use to fill the hanging baskets. Be sure to follow label directions as to how much to use. More fertilizer is not better and can burn plants to death if over-applied. Then follow up by using a water-soluble fertilizer such as Miracle-Gro or one of Peter's formulations for flowering plants every other week through the growing season.

Q. We moved into a new house last fall, and we have several beautiful ornamental grass plants. When should I cut them back?

A. It is best to cut them down in late winter or early spring. Some gardeners cut them back in the fall, but they miss the wonderful interest grasses add to the garden in the winter. Let's face it, gardens need all the interest they can muster during a gray Pittsburgh winter! Whether growing or dormant, grasses respond to the slightest breeze, adding the element of motion to a garden. The rustling of the grass as winter wind blows through the dried blades adds the element of sound.

Enjoy them through the winter and then cut them back to within 4 to 6 inches of the ground before new growth starts. You will make your task easier if you use twine to bind them into a compact sheaf BEFORE you cut them. Use a wrap of twine about a foot from the top and a wrap of twine two-thirds of the way down to the ground to secure all the blades together. It is much easier to manage one bundle of grass than it is to clean up hundreds of individual stems.