September marks the true turning point for gardening in Louisiana, signaling the end of the intense summer growing season. This month is the most opportune time to begin cultivating a successful fall and winter garden, as days shorten and the environmental stresses of extreme heat begin to recede. While the weather may still feel summery, September provides the necessary window for starting cool-season crops that will mature during the state’s milder winter months. Precise timing is fundamental for a successful harvest in this subtropical climate.
Essential Considerations for Louisiana Fall Gardening
Planting in September requires managing the reality of the lingering summer heat, often called a “false fall.” Elevated soil temperatures can prevent the successful germination of many cool-season seeds. To counter this, gardeners should start tender seeds indoors in August or early September, then transplant the established seedlings once ambient temperatures drop later in the month.
Preparation of the garden bed is necessary after the summer’s heavy rains and intense sun. Begin by removing all spent summer crops and perennial grasses, as failure to do so will allow weeds to compete with new plantings. The soil should be tilled or worked to a depth of six to eight inches to break up compaction from the rainy season.
Incorporating organic matter, such as compost or aged manure, replenishes nutrients depleted by summer crops and enhances the soil’s drainage capabilities. Since September is still quite warm, consistent moisture management is necessary for new plantings to establish roots. Applying a two-to-four-inch layer of organic mulch after planting conserves soil moisture and moderates high soil temperatures by shading the root zone.
Food Crops to Start in September
Leafy Greens and Brassicas
September is the perfect time to directly sow or transplant leafy greens that thrive in cooler weather. Crops like collards and Swiss chard are forgiving, tolerating the warmer start of the month when seeded directly. Temperature-sensitive greens like head lettuce should be introduced later, ideally after mid-September, when cooler nighttime temperatures arrive.
For many Brassica vegetables, transplants are the preferred method this month due to their longer maturity times. Broccoli, cabbage, and cauliflower seedlings, ideally started indoors in August, can be set out now to ensure maturity before a hard freeze. Brussels sprouts also require a long growing season and should be established as transplants in September.
Root Vegetables
Several root vegetables are ready to be direct-seeded in the garden now, as they prefer to mature underground without the stress of transplanting. Radishes are a rapid-growing choice, often ready for harvest in 30 to 45 days, making them an excellent crop to fill space between slower-growing plants. Carrots and beets should also be sown directly into the prepared soil, ensuring the seedbed is loose and free of large stones for proper root development.
Beet seeds are technically a cluster of several seeds, meaning thinning the emerging seedlings is necessary to give individual roots room to swell. Carrots require a shallow planting depth, typically about a quarter-inch, and benefit from a light covering of fine soil or vermiculite to maintain contact and moisture during germination. Shallots and garlic, planted as individual cloves or sets, are best planted from mid-to-late September for a winter harvest of green onions or mature bulbs in the spring.
Herbs
Cool-season herbs like cilantro and parsley can be seeded or planted from transplants in September. Cilantro, a fast-bolting herb in the heat, will thrive as days get shorter and temperatures moderate. Parsley is a biennial that provides fresh cuttings throughout the fall and winter, benefiting from a spot that receives morning sun but is shielded from intense afternoon rays.
Ornamental Plants and Flowers for Fall Color
September begins the planting season for annual flowers that provide vibrant color through the fall and into the Louisiana winter. Pansies are a local fall favorite, typically purchased as transplants for instant color in garden beds or containers. These bloomers are known for their resilience and ability to tolerate cooler weather, providing color well past the first light frosts.
Violas, closely related to pansies but featuring smaller blooms, offer a similar color palette and are a good alternative for areas receiving less sunlight. Snapdragons and petunias, chosen for their upright or trailing habit, can be planted as transplants now. These plants have been bred for improved cold-hardiness and will establish root systems before the true cool weather arrives.
For immediate, dramatic autumnal displays, chrysanthemums (mums) are a traditional choice. They are generally bought in bloom as potted plants and placed in the landscape to provide fiery reds, yellows, and oranges synonymous with the season. Heat-tolerant plants such as crotons and marigolds serve as useful “shoulder crops,” bridging the gap between summer annuals and the establishment of cool-season flowers, ensuring continuous landscape interest.