Editor's note: This is the second in a two-part series on "Navigating the Nursery."

Purchasing new plants is exciting for gardeners, but when shopping trips become plant death marches, it may be time to reassess the way you shop. A little preparation can make the difference between plants that barely survive to plants that really thrive.

I would be remiss if I didn't remind gardeners to collect and submit soil samples for analysis prior to adding new plants to the landscape, and to repeat the test every two years. Soil testing is inexpensive, yet the report provides a wealth of valuable information to the gardener.

Once you collect your soil sample, bring it to Clemson Extension Service, where for $6 a sample, it is sent to the Clemson University Agricultural Service Laboratory for testing. The lab provides a detailed report that includes information about soil pH, soil fertility, and nutrient-holding capacity, as well as recommendations for any necessary amendments such as lime, sulfur or fertilizer.

Water quality can be an issue for Lowcountry gardeners who rely on irrigation wells for watering their plants. Seasonal water table changes and natural minerals and salts found in well water may create suboptimal growing conditions for some plants.

Clemson also offers irrigation water testing from $10 to $25. For more information on soil and water testing and other agricultural tests available for home gardeners, go to www.clemson.edu/public/ag_services.html.

Do your homework before buying plants. Research-based websites such as the Clemson Extension Home & Garden Information Center provides factsheets for hundreds of common landscape plants.

Can't find a particular plant? Check the Extension websites of neighboring states with coastal regions and climatic conditions similar to ours such as North Carolina State, University of Georgia, or University of Florida. All of these sites offer in-depth plant profiles and information on plant culture.

Avoid invasive "problem" plants by checking the list available in the Invasive Plant Pest Species of South Carolina booklet found at http://www.clemson.edu/psapublishing/pages/forestry/forlf28.pdf.

When making your plant wish lists, try to include both the common names and the Latin or botanical names. A full botanical name includes the genus and species, as well as cultivar, variety, or trade name.

Showing up at the garden center with only the common name for your plant is like walking up to the paint counter and ordering "off white" paint. Without specifics, there is too much room for error.

Locally owned nurseries offer regionally appropriate plant material and have experienced staff to assist their customers. These professionals can help guide your selections, but a discerning eye will help avoid plants destined for the compost pile.

For example, when buying annuals and perennials:

Choose plants with plump, unopened buds rather than those in full bloom.

Remember that plants that are regularly allowed to completely dry out and wilt become stressed and often struggle to thrive in the landscape.

Avoid off-color foliage, damaged limbs, insect infestations, or other injuries that can spell trouble. Walk past discount racks unless you are willing to take home a sick plant.

Inspect the undersides of leaves and along stems for aphids or scale problems.

Ask the nursery staff to help you gently examine the roots of plants. Healthy roots are plump and whitish in color. Refuse plants with brown, mushy or smelly roots.

Be aware that plants with lush foliage and weak, spindly root systems will suffer in even the best garden settings when the temperature rises.

Trees and shrubs are long-term investments. Avoid purchasing plants if:

The container seems conspicuously small compared to the size of the plant it contains.

The root flare is buried below the soil surface.

There is evidence of excessive pruning on young trees.

Specimens are so pot-bound that the container cannot be cut away without damaging the roots.

Stems and trunks can break, so be sure to carry trees and shrubs by the container or root ball.

Finally, never transport plants home in an open truck bed. Imagine the devastation 60-mph winds would have on a landscape, yet every day shoppers stand hundreds of dollars of plants upright in the back of a pickup truck and whiz home at highway speeds.

Protect new plants by laying them down in the truck bed and covering them with a securely fitting tarp. Loose tarps flapping in the wind can damage foliage and break stems.

Be sure to water plants well upon arriving home, and again before planting. Avoid removing dry roots from containers in order to prevent damage to their tender roots.

Amy L. Dabbs is a Clemson Extension Urban Horticulture Extension Agent. Send questions to gardening@postandcourier.com.