Organic vegetable production in Florida is challenged by plant-parasitic nematodes and sandy soils subject to nitrogen (N) leaching. Researchers planted summer cover crops to enhance N cycling and soil health, suppress pest nematodes and weeds, and improve yield and quality of fall pepper, cucumber, or bok choy. Treatments included sunnhemp (alone or with sorghum-sudangrass or millet) and a four-way mix with sesbania; and preplant organic fertilizer to meet crop N needs versus a half-rate preplant plus fertigation. A winter rye cover crop and spring chard followed vegetable harvest, then the same cover crop and fertility treatments were applied for a second season of fall vegetables. N transfer from cover crop to vegetable was tracked with N labeling; soils were analyzed for nutrients, carbon, nematodes, and microbial communities; and crop and weed biomass and yields were recorded.