Q: I recently retired and moved from South Dakota to South Carolina. I have been looking at garden catalogs and drooling over all the new plants I get to try growing in my garden. I have visited a few garden centers, and I have been told that a lot of the rules that I have grown my garden with, such as using USDA plant hardiness zones to pick plants, no longer apply. What do you think? What should I look for in new garden plants?
A: I usually like finding knowledgeable people at garden centers to get accurate advice for local conditions. Talk to people at several centers, and over time you will be able to tell who is giving you the best information. Even more importantly, check with the local extension service office of the state university to find master gardeners. These offices are set up to give university-researched advice, not to try to sell you products.
No matter where you start out, if you make a long-distance move, the growing conditions will be different, and therefore, the plants will be different. Obviously, the southern third of the country and the West Coast are warmer than the northern two-thirds. For each cold hardiness zone south that you move, spring will be a week or two earlier, and the first frost of the fall will be a week or two later. This gives you a longer growing season with which to work.
An earlier spring means planting earlier, but it also means trees and shrubs will bloom earlier. Migratory birds move north up the continent as these plants flower in the spring.
You may know that the south is much more humid than the north. Some plants thrive in high humidity, and some don't. Fungal disease organisms often thrive in high humidity. Planting disease-resistant varieties is more important in the south but less so in the arid west.
If a plant tag says the plant needs full sun, you may find that afternoon shade is helpful if you are in the south. Plants growing in full-sun conditions may need a thicker layer of topsoil that holds more water between waterings. This may be helped by a layer of mulch. Irrigation may be helpful on the west or sunny south sides. In the north, plants need protection from the winter cold, but in the south, they need protection from too much sun and heat.
Many of the soils in warm climates are not as good as northern soils. The longer growing season in the south allows decay organisms to decay the organic matter. Organic matter provides nutrients to plants and helps hold water in the soil, so you may need to add more on a regular basis. Soils in the south are often very sandy and may be orange in color due to the iron in the soil being exposed to the elements. Soils in the north are black from the carbon in the organic matter.
The longer growing season in the south allows perennials and shrubs to grow longer each summer, so they may grow larger than the same plants growing in northern gardens. The plants are more likely to grow to the larger sizes listed on the plant tag. To fill a flowerbed with perennials, you may need to space the plants just a little bit farther apart than you would in a northern garden.
Jeff Rugg's column, "A Greener View," can be found at creators.com.