I have some 10-20-10 fertilizer and was wonder how much and when should I apply it to my vegetable garden. I have been adding mulched leaves to the garden this winter. There isn't anything growing in the garden at this time.
10-20-10 is a proportionately high phosphate fertiliser and will benefit root growth. I would apply it at planting and sowing time raking or lightly forking it in at a good handful to a sq yd.