What temperatures are best for fertilizing cold weather vegetables?
If you are growing things like lettuce or herbs, top dressing with compost should suffice. Stronger, taller plants require fertilizer. The plant should be actively growing and have at least 2 sets of true leaves before fertilizer is added. The actual temperature is less important. Always water well prior to applying fertilizer to minimize the risk of root burn. I found an article that covers all things vegetable for Tx gardeners. https://agrilifeextension.tamu.edu/browse/featured-solutions/gardening-landscaping/fall-vegetable-gardening-guide-for-texas/