10 Gardening Activities for March in the South

1. Plant Cool-Season Annuals

Cold weather may linger throughout the month, but you can still plant vibrantly colored cool-season annuals such as calendula, pansies, petunias, dianthus, osteospermum, snapdragon, and many daisies. You can combine these flowers with cool-season plants that have great foliage such as Swiss chard, dusty miller, and ornamental kale to fill your garden beds, containers, window boxes, and hanging baskets. You can order plants and seeds online from suppliers such as Proven Winners or Burpee.

2. Cut Back and Divide Perennials

March is often a transitional month in the garden because the weather hasn’t fully warmed up. Use cool and overcast days to cut back and divide perennials throughout your garden. Perennials that you don't divide can be cut back to stimulate new, vigorous growth. As a general guide, cut back and divide perennials that bloom after mid-June such as catmint, coneflower, lamb’s ear, goldenrod, gaura, ornamental grasses, penstemon, sage, tickseed, and yarrow. Some perennials such as delphinium, euphorbia, geraniums, lavender, rosemary, and Russian sage should not be divided.

3. Continue Transplanting Cool-Season Crops

In warmer areas of the South, you may have planted cool-season crops in February. Continue planting crops such as snap peas, broccoli, cauliflower, chard, leeks, lettuce, onion, peas, turnips, and more. Direct sow parsnips, peas, radishes, and spinach. If you have irregular weather where frost can come late, be sure to keep frost protection on hand. Row covers and frost blankets can go a long way in protecting your produce from damage.

4. Keep Warm-Season Crops Growing Indoors

By the end of March all your warm-season crops should be started in seed-starting trays and growing under grow lights. If you started your crops back in February, it’s often best to keep them indoors through March. You won’t speed up the production much by planting outside if the warm weather hasn’t arrived yet. Plan to transplant warm-season crops such as cucumbers, eggplant, melons, peppers, squash, and tomatoes in April, instead. The same theory applies to herbs such as basil or flowers such as marigolds, sunflowers, or zinnia. Start them now and hold off on transplanting them outdoors until April in all areas except the warmest Southern climates.

5. Prune Evergreens

It’s always best to prune evergreens before new growth emerges in spring. Typically, the main reasons to prune evergreens are to control size and shape; remove dead, diseased, or broken branches; or sculpt their appearance. Be sure to avoid unintentionally pruning the central leader (the main growing tip of the tree) unless you're creating a bonsai or cloud-pruned evergreen. Removing it can lead to unhealthy branch structure. For more information on pruning evergreens, review these articles from The Morton Arboretum and Washington State University Extension. There are also good books that cover pruning plants.

6. Feed & Water Roses

March is a good month to wake up your roses by applying a layer of compost around plants and fertilizing them with a rose fertilizer such as Rose-tone. If you have consistent rainfall throughout the month, then hold off on watering; otherwise, you can also resume your regular watering schedule. Proper fertilizer and consistent water will help your roses produce lush growth and lots of roses later in the summer.

7. Plant Spring-Planted Bulbs

Spring-planted bulbs, corms, and tubers that you ordered earlier this year should be arriving this month (many of the bulb suppliers ship bulbs at the best planting time for your zone). Plant your bulbs as soon as you can after they arrive. If you haven’t ordered your bulbs yet, do so now from an online supplier such as Eden Brothers, American Meadows, or Brent and Becky's Bulbs. Or, visit a local garden center where bulbs such as anemone, calla lily, dahlia, gladiolus, lily, ranunculus, and crocosmia will most likely be on display. Plant your bulbs in well-draining soil where they’ll get full sun. Bulbs should be planted at roughly 2 to 3 times the bulb height (for example, a bulb that’s 2 inches tall should be planted 4 to 6 inches deep). When planting, mix in bulb fertilizer and water well.

8. Plant Asparagus & Rhubarb

Asparagus and rhubarb are great perennial crops to plant in spring. Though they can take a season to really get established, they are often worth the wait because they can have high yields. Learn more about planting and growing asparagus and rhubarb at Gardener’s Supply. Search for asparagus and rhubarb roots at Johnny's Selected Seeds or Burpee.

9. Get Your Water Garden Going Again

As the weather warms, replenish water gardens with new plants and feed your fish more regularly. It’s also a good idea to check that filters, pumps, and any other equipment for cleaning the water (for example, UV lights) are functioning properly. If you’re adding plants to your water garden, consider adding a mix of plants that provide habitat, flowers, and visual interest. Try floating plants (water lilies, water lettuce), edge plants (Japanese sweet flag, creeping Jenny), vertical-growing plants (horsetail, cardinal flower), and large-leaved plants (taro, lotus).

10. Restart Lawn Care & Tackle Weeds Early

When temperatures rise and your lawn starts to turn green, restart your regular lawn care regimen. Resume mowing when the lawn reaches 3 inches tall again. It’s fine to fertilize Bermudagrass and Zoysiagrass lawns if they were overseeded; otherwise, wait to fertilize until later in the season. Apply pre-emergent weed suppressors (Espoma Organic Weed Preventer, Green it Organic Weed Preventder), especially to keep crabgrass and other weed seeds from germinating. Applying a pre-emergent will stop many weeds before they start and help control them throughout the season. Many larger weeds and broadleaf weeds are easiest to dig up by hand. Be sure to dig them out before they go to seed and spread throughout your lawn. Learn more about how to get rid of weeds.