As spring begins to take hold across Harris County and the greater Houston area, many homeowners are stepping back into their yards with renewed enthusiasm. March is one of the most important months for gardening in Southeast Texas, marking the transition from cool-season growth to warm-season planting.

According to Harris County Master Gardener Karen Shook, this seasonal shift is the perfect time to prepare soil, care for blooming plants, and establish new trees and vegetables before the region’s intense summer heat arrives. Her March gardening calendar offers practical guidance for homeowners looking to maintain healthy lawns, vibrant landscapes, and productive vegetable gardens.

For residents across Houston, Cypress, Tomball, and the Greater Houston area, following these seasonal gardening practices can help landscapes thrive throughout the year.

Transitioning from Cool-Season to Warm-Season Annual Flowers

March and April represent a crossover period for annual flowers in Southeast Texas gardens.

Gardeners can still plant established cool-weather annuals early in the month, especially those already growing in larger nursery containers. At the same time, it’s a good opportunity to start planting warm-weather annuals from seed or transplant.

Fertilizing is particularly important this time of year. Newly planted flowers benefit from fertilizer to help establish strong roots, while existing plants can receive a nutrient boost to encourage continued blooming.

By April, many gardeners transition fully to warm-season bedding plants as temperatures rise across the region.

Caring for Perennials and Ornamental Grasses

Perennials and ornamental grasses also benefit from attention in early spring.

Shook recommends dividing perennials every three to five years to maintain plant health and prevent overcrowding. For late summer and fall bloomers, early spring is the ideal time to divide them as soon as new growth appears.

Gardeners should also:

• Fertilize established perennials and ornamental grasses
• Remove spent blooms to prevent plants from putting energy into seed production
• Shear back leggy growth by about one-third to encourage fuller plants

These simple maintenance steps help keep garden beds looking tidy while supporting strong seasonal growth.

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Bulb Care and Planting Summer Bloomers

Spring is also an important time for bulb care in Houston-area landscapes.

As spring-blooming bulbs begin actively growing, gardeners should apply a light fertilizer to support flowering. Meanwhile, summer-flowering bulbs like gladiolus can be planted now.

Planting gladiolus every two weeks from January through May can provide continuous blooms throughout the season. When cutting flowers for arrangements, gardeners should leave several leaves on the plant so it can continue producing energy.

Most bulbs also benefit from division every two to three years to maintain strong flowering performance.

Rose Care: Preventing Disease and Supporting Growth

Roses require regular attention in early spring.

Once new growth appears, gardeners should begin a weekly fungicide program every seven to ten days to help prevent common diseases such as blackspot and powdery mildew. Fertilizing roses monthly also supports strong growth following late-winter pruning.

Spring gardening can also bring encouragement after winter weather challenges. Shook shared a personal reminder of how resilient plants can be.

“I hope everyone’s garden came through our cold weather in good shape. Remember, don’t prune cold-damaged plants right away just because the dead foliage looks bad. Give the cold damaged plants some time to recover.”

She added an example from her own garden:

“I have a beautiful gardenia that I almost gave up on after Uri. The ‘cold hardy’ one I bought to replace it didn’t survive, but the original recovered!”

Trees and Shrubs: Plant Before the Summer Heat

March is a key planting window for shrubs and trees across Harris County.

Planting early gives root systems time to establish before the region’s intense summer temperatures arrive. Newly planted trees and shrubs may require additional watering while roots develop.

Established shrubs can be fertilized every six to eight weeks using balanced fertilizer ratios such as 3:1:2 or 4:1:2. Citrus trees should also be fertilized when new growth begins.

For spring-flowering shrubs like azaleas, pruning should wait until after blooms finish. Gardeners should also check soil acidity for acid-loving plants to ensure proper growing conditions.

Lawn Care: Let Grass Wake Up Naturally

For Houston lawns, March is primarily a transition period.

As grass begins to green up, mowing can gradually resume, but Shook advises homeowners not to overwork their lawns too early in the season. Allowing root systems time to strengthen will result in healthier turf later in the year.

Fertilizing lawns should wait until grass has been mowed twice while actively growing. If weeds are present, clippings from early mowings should be bagged and composted rather than left on the lawn.

Broadleaf weed killers are typically used in April, but homeowners with St. Augustine grass should read labels carefully, as the variety can be sensitive to herbicides in warmer temperatures.

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Spring Vegetable Gardening in Southeast Texas

For vegetable gardeners, March brings one of the most rewarding times of the year.

Spring gardens often include harvesting cool-season crops while simultaneously planting warm-season vegetables.

Preparing soil is essential for success. Gardeners should incorporate compost and fertilizer before planting. Tomatoes, in particular, should be planted early enough to produce fruit before extreme summer heat stops production.

This early planting window is especially important for Houston-area gardeners hoping for strong yields. Need some inspiration? The Harris County Vegetable Garden Planting Guide offers specific recommendations for what to plant this month.

Groundcovers and Vines: Final Preparations Before Summer

March is also the final opportunity to establish many groundcovers before temperatures climb.

Gardeners should finish planting, dividing, or transplanting groundcovers to ensure plants are established before summer heat arrives. Existing groundcovers can also be fertilized or lightly trimmed if they appear untidy.

For woody vines that bloom in spring, pruning should occur only after flowering finishes. Light trimming and guiding vines along supports can keep them neat and encourage healthy growth.

Managing Water During a Dry Spring

Weather patterns also play an important role in garden success.

Shook notes that rainfall has recently been below average while temperatures have been above average in the region. Maintaining mulch layers can help conserve moisture and regulate soil temperature.

She encourages gardeners to monitor soil moisture regularly.

“Keep a good layer of mulch and as always, check for ‘too wet, too dry, just right’ and water accordingly.”

Deep watering is generally more effective than frequent light watering, helping plants develop stronger root systems.

What Houston-Area Gardeners Can Expect This Spring

Despite fluctuating weather patterns, early spring remains one of the most beautiful times of year for Houston gardens.

“I am definitely ready for spring gardening. At this point, bluebonnets and azaleas are blooming. I can’t wait for the amaryllis and iris to join,” said Shook.

For residents across Harris County and surrounding communities, following these March gardening tips can help ensure healthy lawns, vibrant flower beds, and productive vegetable gardens throughout the growing season.

Whether you need advice on soil health, pest control, or seasonal planting, the Master Gardeners are a valuable resource. Residents can reach out with gardening questions through the HCMG Help Desk at txmg.org/hcmga/ask-a-question, by visiting their website at hcmga.tamu.edu, or attending one of their local events and educational programs.

Stay tuned to My Neighborhood News for more seasonal gardening tips, local environmental initiatives, and community resources for homeowners across the Greater Houston area.

By Tiffany Krenek, My Neighborhood News 

Tiffany Krenek has been on the My Neighborhood News team since August 2021. She is passionate about curating and sharing content that enriches the lives of our readers in a personal, meaningful way. A loving mother and wife, Tiffany and her family live in the West Houston/Cypress region.