“What is the best nutrient to use when preparing for a vegetable garden in the winter months?” Question from Denise of Clemmons, North Carolina
Answer: Vegetable fertilization regimes always depend on the plants you are growing. Winter crops for cold frames or hoop gardens tend to consist of cold-tolerant greens, herbs, and root crops. Nitrogen is the best fertilizer for growing leafy crops, while phosphorus and potassium support strong root growth.
If you do not plan to plant winter vegetables in your garden, wait until spring to add an all-purpose granular fertilizer for vegetables. Or you can also consider planting a nutritious winter cover crop, like winter wheat or buckwheat. This article lists a few good cover crops that naturally feed the soil.
There is one more point to consider, your choice of organic versus inorganic fertilizers. Organic fertilizers generally contain nutrients that are converted into accessible forms by soil microbes before plants can use them. These microbes are less active in the cold, to the nutrients will be less available to plants, so inorganic fertilizers will make nutrients more readily available to winter crops.
Black Gold Horticulturist