Q. I have many varieties of Narcissus in my garden and some are not blooming as well as they used to. What can I do to help?

A. There are several reasons why flowering bulbs will produce foliage but few flowers:

• Need for division: As with many perennials, the center of a clump of daffodil bulbs may lose vigor and weaken as the clump expands outward. These plants require division. After the foliage has yellowed, dig up the clump and divide it into small sections. Replant each section in full sun at the same depth it was planted before, water well, and top dress with an organic balanced fertilizer.
• Insufficient sunlight: Most Narcissus prefer full sun, although they will tolerate partial shade. Over time, surrounding trees will cast more shade as they grow larger. Divide and relocate your bulbs to a sunnier site.
• Depleted soil: As bulbs multiply over the years, they occupy more space in the garden and consume more nutrients from the soil. These nutrients need to be replaced by adding organic matter to the soil twice a year, or by mixing a slow-release fertilizer with the soil above the bulbs. Take care not to place fertilizer directly on or below the bulbs.
• Damage to foliage: After the bulb has flowered, the stems and foliage must remain attached to the bulb until they begin to lose their green color. This signifies that they have finished fortifying the bulb with the food it will need to bloom the following year. If the foliage was removed prematurely or damaged due to disease, this might adversely affect flower production. Braiding, tying, or clumping the leaves into a bunch prevents sunlight from reaching all parts of the leaves, and is therefore not advised.