Q: When is the time to fertilize spring bulbs like daffodils and hyacinths?
A: One of the adages of garden fertilizing is to feed plants when the leaves are growing.
When the leaves of spring bulbs poke out of the ground, they mark the beginning of the bulb fertilizing season. This is the time when roots are most active.
Actually, there are two good times to fertilize spring bulbs: in September, with slow-release fertilizer (Osmocote, Dynamite, Milorganite, etc) or in late February with fast-release fertilizer (10-10-10, Miracle-Gro, etc). This is the rationale: by feeding slowly from September through March, bulb roots absorb nutrients and the bulb prepares itself for flower emergence in spring. If you miss the fall date, a fast-release fertilizer applied well before flower emergence stimulates leaf growth, which then feeds the bulb after flowering. My advice? Grab some water-soluble houseplant fertilizer and feed your bulbs before March arrives.