Q: I am a habitué of cemetery dumps. Last spring I rescued 75 pots of spent spring bulbs and planted them in my garden. Now I’m anxiously awaiting their appearance, and wondering how best to handle the bulbs I hope to haul back from the grave this year. — Sabra Fenske, Nazareth, Pa.
A: Well, your source of bulbs is certainly unusual, but your question isn’t. Most of us have wondered what to do with forced bulbs that are past their prime. As their foliage begins to lengthen and yellow, the thought of keeping them in the house becomes less and less appealing. Most forced bulbs — aside from the cold-tender paperwhite narcissus, Narcissuspapryraceus — can find a new life in the garden. The problem is that it’s often too early to plant them outdoors when they’ve finished blooming indoors. That horrid foliage is part of the deal. Crocus, Iris reticulata, hyacinths, daffodils, and tulips all have similar life cycles — a brief spurt of growth is followed by bloom, then another short period of leaf growth, followed by dormancy. For several weeks after flowering, the leaves continue to grow and to manufacture food for next year’s display. If the leaves are removed prematurely or the plant is not given sufficient light and moisture while they’re growing, the bulb will starve.
Your best bet is to find an out-of-the-way, cool and sunny spot in the house, perhaps crammed in behind foliage plants. Water the bulbs enough to keep the soil lightly moist. (If it’s too wet, the bulbs will rot.) Add a half- or quarter-strength solution of fertilizer each time you water. When the foliage has turned completely yellow and can be removed with just a light tug, it’s a sign that the bulbs are entering dormancy, so stop watering and fertilizing them. Since they don’t need light either, you can now store the pots just about anywhere until the ground outside is workable for planting. A garage or unheated porch with a wide day/night temperature fluctuation is ideal for most forced bulbs, as it simulates natural conditions. In spring, when the soil has thawed and dried, plant the bulbs in the garden. They will need to go deeper than they were in the pot — 3 to 4 inches deep for the little ones, 7 to 9 inches for the larger ones. Space them at least twice the width of a bulb apart. The forcing process depletes the plant and it requires considerable time to recover. It will take at least a year, usually two, for a forced bulb to regain its full strength. Enjoy your heist.