It's time to buy more plants!

Your first impulse may be to buy what is in full bloom right now. That's fine, but think about the rest of the year, too. You might save some of your gardening budget for later in the season, so you can see and purchase plants that bloom in summer or fall or have other desirable seasonal features.

Although landscape designers will say you should purchase plants that fit into your design, most gardeners tend to purchase something they like, then walk around with it in their hands as they determine where to squeeze it into their garden. They may even plant it and then decide to move it, maybe even more than once.

Ideally, you should know what conditions a plant needs to grow before purchasing it, and definitely before planting it.

Plant tags often provide key information, including light, soil and moisture requirements and hardiness as well as ultimate size. This information will help you determine the best location.

It is important to know the ultimate size of any plant you purchase, especially trees and shrubs. Do not plan to keep a plant small by pruning. You'll be setting yourself up for a lot of work, year after year.

Martha Rial, Post-Gazette If annuals, such as petunias, are in flower when you buy them, snip off the flowers as you plant them to direct the plant's energy to the roots. Click photo for larger image.

Plants should look healthy; bargain plants often turn out not to be. Unless you are an experienced gardener, you probably don't want to try to save "sick" plants.

Do not buy plants with whiteflies (small white insects that fly around when the plant is brushed) or other insect pests.

Plants should be labeled with the complete botanical name -- genus, species and cultivar, if applicable. A reputable business will use these names. Plants should appear to be well taken care of. The soil should be moist, and the plant should not be wilted. There should not be weeds in with the plants.

Carry plants by root ball or pot, not by the stems or the trunk. Nursery personnel should do the same. Otherwise, the roots can be damaged or stems broken.

Annuals and vegetables

Generally, it is best to purchase vegetables, such as tomatoes and peppers, without flowers and fruit. When you plant annuals and vegetables, and, in fact, all plants, the first thing you want them to do is develop a good, strong root system that will be able to support the plant into the future. If the plants are already flowering and fruiting, that will use a lot of energy that should be going to the root system. An exception might be if you are buying a "patio" tomato that is growing in a large pot.

Annuals are also best planted before they are in bud, but few gardeners follow this rule. Alternately, purchase annuals in flower, then snip off the flowers as you plant them to direct the plant's energy temporarily away from flowering and to the roots. You will be rewarded with a strong plant that will produce many flowers over the summer.

Trees

Trees should be well-shaped. For most trees, this means one main leader and no crossing or broken branches.

You will find plants for sale everywhere at this time of year. Nurseries, garden centers and even the big box stores will have a great selection. You can find more unusual plants and less common varieties through specialty catalogs and online nurseries. Plant societies specialize in particular plants and are a good source of the newest plants as well as information. You may also find treasures at local plant sales sponsored by garden clubs, plant societies and other groups.