By Marilyn Fujiyoshi, Colorado State University Cooperative Extension, Master Gardener, Denver County
When choosing healthy plants, remember the three bywords: Appearance, appearance, appearance. This applies to annuals, perennials or vegetables.
For example, if the only difference in appearance of two plants side by side is one with tight buds and one in flower, go with the plant in bud. Or, if the only healthy plants are in flower, be ruthless and cut off the blooms. Plants suffer less transplant shock and develop roots faster if they are without blooms. New buds will appear in two weeks or so.
In addition to buds, look for plants bearing vigorous, well-shaped leaves with a bright rich color. Leaves should be free of insects and disease symptoms. Also check for signs of pests on the stems, particularly near the soil line. If you see something that looks abnormal to you, ask a staff person.
The second aspect of appearance is bushiness. Does the plant have a well-branched structure typical of the species or is it leggy or lopsided? Does it fill the pot or cellpack? Has its growth been compromised by competition from a weed growing alongside?
Now, for the moment of truth: Check the plant's roots, which probably are the most important part of the plant. If the roots are in poor shape, usually the top will tell you. Slightly stressed roots, however, may not be obvious from top appearance.
Though it's perfectly appropriate to gently ease a plant out of the container to look at the roots, check with a staff person at the greenhouse or garden center if you are uncertain how to do this. You should find a well-formed network of whitish roots binding the soil together. If the roots are brown, soft or rotten reject the plant.
If you find a mass of thick roots and little soil, the plant is rootbound and perhaps slightly past its prime. You will need to trim away larger roots circling pots and tease out all rootbound soil masses before planting.
The other extreme is plants with few roots and with soil that easily falls away. These are plants that have not yet reached their prime and, if you purchase them, you will have to grow them in the original containers for a few more weeks before transplanting.
Remember to look for three things when purchasing plants:
As with all consumer purchases, ask lots of questions such as whether plants can be set out before the last frost date (about May 10 in Denver) or whether you will have to hold them in a protected place for weeks. Shop around for a store with staff willing to answer your questions and don't purchase solely on the basis of price alone.
If you have additional questions about choosing plants, contact your county office of Colorado State University Cooperative Extension.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010