With the official start of spring just a few weeks away, now is the time to prepare your garden for the future flowers, vegetables and plants you’d like to enjoy through the upcoming season and into the summer and fall months.

“If you have not already done so, now is the time to prepare final beds for planting flowers and vegetables,” said Larry Stein, Ph.D., horticulture specialist at the Texas A&M AgriLife Extension Service, Uvalde. “You may want to consider renting or buying a garden tiller to speed up the process; however, a strong back and a garden fork will still do an excellent job.”

He said for every 100 square feet of bed area, work in a several-inch layer of either compost, pine bark or sphagnum peat moss, plus 5 pounds of a 3-1-2 fertilizer like 15-5-10. 

Pruning of evergreens and summer flowering trees and shrubs is typically completed in early March; however, it is best to take a wait-and-see approach this year, said Stein. Prune spring flowering trees and shrubs as soon as they finish blooming. Now is also a prime time to establish, renovate and/or aerate lawns.

Stein, who is also an associate department head and professor within the Department of Horticultural Sciences in the Texas A&M College of Agriculture and Life Sciences, offered additional gardening tips for March.

Check your region’s freeze date

Tomatoes on the vine. The color varies from green to red in various stages of ripening. Tomatoes are among the plants gardeners should prepare for a late frost should one occur.
Tomato and pepper are among the plants gardeners should keep an eye on in March. Texans should have a plan to prepare for a late frost should one occur. (Texas A&M AgriLife photo by Laura McKenzie)

See the planting guide on the Aggie Horticulture website for your area’s average last killing freeze date. Remember, though, that killing freezes can occur after this date. Stein said North Texans still have time to plant seeds of their favorite annuals in flats to transplant outdoors when the danger of frost is past. 

Keep an eye on tomato, pepper transplants

Often, tomato and pepper plants started outdoors from seed will grow so quickly that they will catch up with commercial plants in size within a few weeks. Stein said for many gardeners, this is the only way to obtain rare or heirloom varieties.

But because this has been a winter with erratic weather patterns, it’s best to keep an eye on young tomato transplants so that they may be covered if the threat of a late frost occurs. He also said gardeners shouldn’t be in a hurry to set out young pepper plants. Wait until the temperatures seem to be settled. 

Plant warm-season vegetables

Yellow squash on the vine
March is the time to plant warm-season vegetables. (Texas A&M AgriLife by Laura McKenzie)

Plant warm-season vegetables from seed. The planting guide can suggest prime planting times for corn, beans, squash and other vegetables. 

Pot up to protect from frost, repot for summer color

Many gardeners opt to pot up their transplants in larger containers to grow a more extensive root system prior to planting and to make it easy to move the plants inside in case of a late spring frost. Repot overgrown container plants as well as plant containers of tropical plants for a stunning display of summer color.

Select and order plants

Now is the time to select and order caladium tubers, as well as geranium and coleus plants for late April and early May planting. Do not plant caladiums until soil temperature reaches 70 degrees. 

Beware of what you buy

Beware of close-out sales on bare-root trees and shrubs. The chance of survival is relatively low on bare-root plants this late in the season. Your best bet at this time of year is to depend on container-grown or balled and burlapped plants for landscape use.

Prepare and plan for color

Start hanging baskets of petunias and other annuals for another dimension in landscape color. Plant dahlia tubers in fertile, well-drained soil. Blue plumbago can be planted now for season-long, low-maintenance color.

It is usually cold hardy to Zone 8 and in sheltered places elsewhere. Although tolerant of sunny conditions, blue plumbago prefers a little protection from the hot afternoon sun. It is quite drought-tolerant and blooms from spring till frost. 

Fertilize flowers

Red roses in bloom at The Gardens at Texas A&M. A single bud opening stretches above the open blooms,
Starting in March, roses should be fertilized regularly through September. (Texas A&M AgriLife photo by Laura McKenzie)

Fertilize roses every four to six weeks from now until September. As camellia and azalea plants finish blooming, fertilize them with three pounds of azalea-camellia fertilizer. Check mulch on azalea and camellia beds and add where needed. 

Divide summer and fall perennials

Dig and divide summer and fall flowering perennials just before they initiate their spring growth. One attractive begonia plant can yield a number of others through careful rooting of stem cuttings.

Thin wildflower seedlings

Now is a time to thin larkspur and other wildflower seedlings. Plants will bloom much better if thinned to about 4 inches apart. Transplant or share the extras with gardening friends.

Enjoy spring-blooming wildflowers and make a note to not mow until they have set and realized their seed. Wildflowers will respond to fertilizer just as other plants do.

Collect oak leaves for mulch

Continue to collect oak leaves to amend your planting beds; they are slow to break down, so they make an excellent mulch the first year but will significantly help the tilth of the soil in the coming years.

Susan Himes
 
Susan Himes is a writer and media relations specialist for Texas A&M AgriLife. She writes news releases and features from science-based information generated by the agency. She also covers human interest stories and events across the state.
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