April marks a significant transition in North Carolina gardens, signaling the shift from cool-season crops to warm-season varieties. This period is characterized by rapidly warming soils and lengthening daylight hours, creating ideal conditions for planting heat-loving vegetables, herbs, and flowers. Gardeners across the state begin moving tender plants outdoors and sowing seeds that will flourish during the summer months. Successful gardening in April depends heavily on understanding local weather patterns and soil conditions, which vary widely across North Carolina’s diverse geography. This guide provides a focused approach to planting based on the state’s distinct environmental zones.
Understanding North Carolina’s Planting Regions
North Carolina’s considerable length and elevation changes create three distinct gardening regions: the Mountains, the Piedmont, and the Coastal Plain. These regions experience vastly different average last frost dates, which directly impacts when it is safe to plant heat-sensitive crops.
The Coastal Plain often sees its last frost as early as late March, allowing gardeners to begin transplanting warm-season crops in early to mid-April. The central Piedmont region typically has its final frost in the first half of April. Gardeners in this zone usually wait until mid-to-late April to place tender transplants outside. The Mountains region presents the most conservative planting timeline, with the last frost often occurring closer to the end of April or even into mid-May. The core principle remains waiting until the threat of a hard freeze has passed and nighttime temperatures are reliably above 50°F before introducing sensitive plants.
Warm-Season Vegetables Ready for Transplanting
Mid-to-late April is the perfect window to set out warm-season vegetable transplants like tomatoes, peppers, and eggplant into the garden, especially in the Piedmont and Coastal regions. These nightshade family members require a long, warm growing season, making them prime candidates for starting indoors several weeks before the last frost. Tomato plants should be buried deeply, as they will sprout roots along the buried stem, leading to a stronger root system.
Before planting these tender starts, “hardening off” is necessary to prevent transplant shock. This involves gradually acclimating the plants to outdoor conditions by exposing them to increasing periods of direct sunlight and wind over one to two weeks. Placing transplants outside too quickly can cause leaf burn, stunted growth, or even death. Eggplant and basil transplants should be held back slightly longer than tomatoes and peppers, often waiting until the final week of April or the first week of May when nighttime temperatures are consistently in the mid-50s.
Seeds to Direct-Sow in April
April’s warming soil makes it an ideal time for direct-sowing many popular summer crops that do not tolerate root disturbance well.
Beans
Beans, both bush and pole varieties, should be planted about one inch deep. Bush beans are spaced two inches apart, and pole beans require six inches between plants for proper air circulation and vining space.
Corn
Sweet corn is another staple to sow directly now. Plant corn in short, square blocks rather than long rows to ensure adequate wind pollination for full kernel development.
Cucurbits
The cucurbit family, which includes summer squash, zucchini, and cucumbers, thrives when seeded directly into warm garden beds. Plant these seeds in “hills” or small groupings of three to four seeds, later thinning to the strongest one or two plants per hill. For vining plants, install a trellis or support system at the time of planting to prevent damage to the young roots later.
Sunflowers
Direct-sowing sunflowers in April provides a quick-growing ornamental and edible crop. Plant large seeds half an inch deep and space them 12 to 18 inches apart for robust stalk development.
Essential Flowers and Herbs
April is a productive month for establishing annual flowers and perennial herbs that will provide color and flavor throughout the summer. Annual flowers like zinnias, marigolds, and cosmos can be easily direct-sown into the garden soil once the danger of frost has passed. These flowers germinate quickly, thrive in full sun, and are highly attractive to local pollinators.
For herbs, heat-loving basil should be planted or transplanted toward the end of the month, as it is extremely sensitive to cold temperatures. Other herbs, such as cilantro and dill, can still be direct-sown in April, though they may “bolt,” or go to seed, quickly once the intense heat of June arrives. April is also a suitable time for dividing and transplanting overcrowded perennial flowers and herbs that have just emerged from winter dormancy, allowing them time to establish new root systems before the summer heat stresses them.