September marks the transition from summer to fall gardening in North Carolina, initiating the second planting season of the year. The shift in temperature allows for the successful cultivation of cool-weather crops that struggled in the intense summer heat. This period is often referred to as the second spring, presenting an opportunity to extend the harvest into the late fall and early winter months. This cycle prioritizes crops that benefit from decreasing day length and cooler soil temperatures.
Preparing the Garden for Fall Planting
The preparation for a successful fall garden begins with clearing out spent summer plants, such as faded tomatoes, peppers, and squash vines. Removing this decaying organic matter reduces overwintering sites for pests and diseases. Next, amend the soil by incorporating compost or other organic matter to replenish nutrients depleted by summer crops. This also improves soil structure and water retention for newly planted seeds and transplants.
September requires quick action, especially for crops needing a longer maturation period before the first frost. Plant slow-growing brassicas and root crops early in the month. Monitor for fall pests like cabbage worms, flea beetles, and aphids, which target tender new cool-season growth. Watering thoroughly after planting encourages deep root establishment and aids in seed germination, as the soil may still retain summer warmth.
Essential Cool-Season Vegetables and Herbs
September is the ideal month for sowing leafy greens, which thrive in the mild conditions of a North Carolina autumn. Leaf lettuce, spinach, and kale can be direct-seeded for a continuous harvest. These crops benefit from succession planting, where small batches are sown every two to three weeks through mid-fall to ensure a steady supply. Cooler temperatures improve the flavor of greens like kale and collards, making them sweeter after a light frost.
Root vegetables are also ideal for direct sowing in September, allowing them time to size up before the soil freezes. Carrots, radishes, and beets should be planted directly where they will grow, as they do not transplant well. Radishes mature quickly, often ready for harvest in under a month. Turnips and beets should be harvested before a hard freeze, though mulch can protect them and extend the harvest window.
Brassicas, including broccoli, cabbage, and cauliflower, require a longer growing period. They are best planted as transplants in early to mid-September. These transplants need consistent moisture and nutrients to form their heads before winter weather arrives. Cilantro and parsley are two herbs that flourish in the cooling weather, providing fresh flavor long after warm-season herbs like basil have faded. Both tolerate light frost and continue to produce leaves throughout the fall.
Planting Flowers and Spring-Blooming Bulbs
For immediate color in the fall landscape, September is the time to set out cool-season ornamental plants like pansies, violas, and ornamental cabbage and kale. Pansies are valued for their ability to bloom through mild North Carolina winters and rebound strongly in the spring. These flowers perform best when planted now, giving their root systems time to establish before the coldest weather. Planting them in well-drained soil and providing fertilizer will encourage fall and winter flowering.
The fall season is also when planning for spring color begins with the planting of spring-blooming bulbs, such as daffodils, tulips, and hyacinths. While bulbs can be purchased in September, many gardeners wait until the soil temperature drops consistently below 55°F, often in mid-to-late October or November, to plant them. This chilling period is necessary for the bulbs to initiate the chemical changes required for flowering in the spring. Planting them too early can lead to premature top growth, which is vulnerable to winter damage.
Daffodils are recommended for their deer resistance and tendency to naturalize and multiply over the years. Tulips require careful timing and are often treated as annuals in the warmer zones of the state. Bulbs should be planted at a depth of two to three times their height in a location that receives full to partial sun during the spring.
Regional Timing Differences Across North Carolina
North Carolina’s diverse topography creates variations in planting deadlines across multiple USDA Hardiness Zones. The state is divided into three regions: the Mountains, the Piedmont, and the Coastal Plain. This geographic difference impacts the expected date of the first frost, which is the deadline for many fall vegetable crops.
Gardeners in the cooler Mountain region (zones 6a and 6b) must adhere to earlier planting schedules, as the first frost arrives in early to mid-October. This requires planting long-maturing crops like cabbage and broccoli in August or early September. Conversely, the warmer Coastal Plain (zones 8a and 8b) may not see a first frost until November or later.
The Piedmont region, the state’s central belt, falls between these extremes, with the first frost expected in late October. Planting windows in the Piedmont and Coastal Plain are more forgiving, allowing gardeners to plant quick-maturing greens deeper into September. Understanding these regional climate variations is key to calculating the proper planting date, which involves counting backward from the expected first frost to ensure crops mature in time.