September marks a significant turning point for gardeners in Alabama, as the oppressive heat of summer begins to recede. This transition month signals the start of the second major growing season, moving away from heat-loving summer crops toward productive cool-weather harvests. Alabama’s southern climate and mild winters allow for an extended fall and winter growing period, making September the ideal time to establish plants that will thrive in cooler temperatures.
Preparing the Soil for Fall Planting
The shift in seasons requires immediate action in garden beds where summer crops have finished their cycle. Begin by completely removing spent plants, such as tomato vines or pepper plants, which may harbor latent diseases or attract late-season pests. Examining the remaining soil for signs of common late-season issues, like spider mites or fungal infections, prevents them from carrying over to the new plantings.
Once beds are cleared, focus on soil rejuvenation and nutrient replacement. Incorporating generous amounts of organic matter, such as compost or aged manure, helps improve soil structure and water retention for the cooler months. Lightly tilling or turning the top few inches of soil allows amendments to integrate effectively and encourages healthy root penetration. Applying a balanced, slow-release fertilizer ensures nutrients are readily available to support the robust initial growth required for a strong fall crop.
Cool-Season Vegetables to Plant
September is the perfect month for planting leafy greens that prefer decreasing temperatures. Loose-leaf lettuce varieties, Swiss chard, and spinach can be direct-seeded into prepared garden beds for continuous harvests beginning in late fall. These greens germinate quickly in the still-warm soil and flourish once daytime temperatures consistently drop below 80 degrees Fahrenheit.
Hardier greens like kale and collards are excellent choices for September planting and tolerate light frosts, often improving in flavor after a chill. These plants benefit from consistent moisture as they establish root systems that will support growth through the winter. Planting smaller successions every two to three weeks ensures a continuous supply of fresh leaves rather than a single, overwhelming harvest.
For slower-maturing brassicas, success often depends on using transplants rather than direct seeding in September. Crops like broccoli, cabbage, and cauliflower require a longer growing period to develop edible heads before the first hard freeze arrives. Starting with established seedlings gives these plants a significant head start, allowing them to mature fully within the shorter fall season.
When setting out brassica transplants, spacing is important to ensure adequate air circulation, which helps prevent common fungal diseases as temperatures cool. These heavier feeders benefit from an initial application of nitrogen-rich fertilizer to support their dense leaf and head development. Monitoring for common pests, particularly the cabbage worm, remains necessary even as the season changes.
Root vegetables are particularly well-suited for direct seeding during September. Carrots, radishes, and beets should be sown directly into the garden bed where they will remain, as they do not transplant well. Radishes mature rapidly, often ready for harvest in just three to four weeks, making them an excellent choice for filling small gaps between slower-growing crops.
Carrots and beets require loose soil free of large stones or clumps, which can cause roots to fork or become misshapen. Thinning the seedlings once they emerge is necessary to give remaining plants enough room to develop properly underground. The cooler soil temperatures of late fall are ideal for developing the sweet, crisp texture desired in these root crops.
Ornamentals and Flower Bulbs
Beyond edible crops, September is a prime time for establishing ornamentals that provide color throughout the fall and prepare the garden for a vibrant spring display. Pansies and violas are cool-season annuals that thrive in mild Alabama autumns and often persist through the winter. Planting these now ensures a blanket of color that will last until the following spring.
Chrysanthemums, or mums, are another garden staple for fall color and are best planted in September to enjoy their blooms as the weather cools. While often treated as annuals for porch displays, planting them directly into the garden early allows them to establish a robust root system before the ground cools significantly.
Establishing spring-flowering bulbs, such as daffodils, hyacinths, and certain tulip varieties, is done effectively in September and October. While many spring bulbs require a chilling period to properly bloom, planting them now allows roots to anchor securely in the soil before winter dormancy. Cool-season biennials and perennials, including snapdragons and dianthus, also benefit from being planted now, enabling them to transition easily into full bloom when spring warmth returns.