April marks the definitive shift from cool-season crops to the warm-season planting schedule for Texas gardeners. Rising temperatures and lengthening days signal that the threat of frost is receding across much of the state, permitting the introduction of tender plants. However, due to the sheer size of Texas, April is not a single planting window but a complex, localized calculation. Success depends on understanding the climatic differences across the state, which dictate the precise timing for safely introducing heat-loving vegetables, herbs, and flowers.
Regional Considerations for April Planting
The state’s vast geography creates three distinct planting schedules that influence April decisions. In the South Texas and Gulf Coast regions, the last freeze often occurs in January or February, making April a period of established growth. Gardeners here enjoy a growing season that can exceed 350 days, allowing them to plant heat-sensitive crops early in the month.
Central Texas and the Hill Country, including major metropolitan areas, generally experience their final frost between March 11 and March 20. For this middle section, April is the time to transition transplants outdoors after the soil has warmed up. The most conservative timing is necessary in North Texas and the Panhandle, where the last frost often falls into the first or second week of April.
Planting timing depends not only on air temperature but also on soil temperature, which is a significant factor for seed germination. Warm-season crops like tomatoes and peppers require the soil to reach 60°F to 65°F for optimal root development. Warmer crops, such as melons and sweet potatoes, often require a sustained soil temperature of at least 70°F before they will thrive. Using a soil thermometer provides a more accurate and reliable indicator than air temperature, ensuring that seeds and transplants do not suffer from cold-induced shock or delayed germination.
Warm-Season Vegetables for Direct Sowing or Transplant
April is the month for installing the crops that will constitute the bulk of the summer harvest. The method of planting is determined by the plant’s sensitivity to root disturbance and its growth cycle. Vegetables with a deep taproot or those that germinate quickly are best suited for direct sowing, where the seed is placed directly into the warm garden soil. This group includes all varieties of beans (bush, pole, and lima), which germinate rapidly in soil temperatures above 60°F.
Corn and okra are ideal for direct sowing in April across Central and South Texas, as their root systems strongly dislike being moved. Okra, a highly productive vegetable that tolerates intense summer heat, should be planted when soil temperatures are consistently over 70°F. The cucurbit family (squash, cucumbers, pumpkins, and melons) should also be direct-seeded in April, especially in the warmer regions. While starting these as transplants is possible, they are highly susceptible to transplant shock and often catch up quickly when sown directly.
Conversely, many long-season, heat-loving crops are started from transplants, which are young plants grown in a protected environment for six to eight weeks. These tender plants require a head start to ensure a harvest before the intense summer heat causes production to slow down or cease. Tomatoes, peppers, and eggplants (all members of the Solanaceae family) are prime examples of crops that should be transplanted in April across Central and South Texas.
Transplanting allows these plants to establish strong root systems before facing the full intensity of the Texas summer sun. Gardeners in North Texas and the Panhandle should aim to transplant these crops later in April, or even early May, after the last frost has passed. Sweet potatoes, grown from vegetative sprouts called slips, should also be planted in April once the ground is thoroughly warm. These slips quickly establish a robust root system necessary to support their extensive vine growth.
Sowing Herbs and Ornamental Flowers
April is the perfect time to introduce aromatic herbs that thrive in the coming heat, offering both culinary utility and ornamental appeal. Basil (Ocimum basilicum), a tender annual that requires significant warmth, should be direct-seeded or transplanted after all frost danger has passed. Its growth accelerates rapidly once nighttime temperatures remain above 60°F.
Hardier, woody herbs like rosemary (Salvia rosmarinus) and sage (Salvia officinalis) can be planted from transplants in April, as they are well-suited to the state’s warm climate and well-draining soils. Rosemary cultivars like ‘Arp’ are known for their enhanced cold tolerance, which is beneficial for the occasional late-season cold snap. Mint and lemon balm are also excellent choices, although mint is often best grown in containers to prevent its runners from taking over the garden space.
For ornamental color, gardeners should focus on annual flowers that possess a high degree of heat and drought tolerance. Zinnias and marigolds are reliable choices that can be direct-seeded in April; they germinate quickly and offer continuous blooms throughout the summer. Their seeds require only moderate soil temperatures and will rapidly produce sun-loving blossoms. Other excellent transplant options include Vinca (Catharanthus roseus) and Lantana, which are highly regarded for their ability to withstand the hottest summer days and continue flowering.