Cooling Bulbs and Why
Most, if not all, bulb suppliers will harvest bulbs in the Fall and store them in coolers until March and April for sales. This prevents them from sprouting too soon so people in the coldest regions can get their bulbs as the temps warm up for Spring planting. You can do the same thing by storing your early ordered bulbs or your existing garden bulbs in the refrigerator for a later than normal bloom time. But be careful – refrigerators will dry them out fast. Store them in a paper bag with damp (not wet) potting soil. Do not use a plastic bag or your garden soil. Store them in the vegetable bin and check the bulbs every seven days or so to make sure they haven’t dried out.
For best results: pre-chill the bulbs for a minimum of six to eight weeks in a refrigerator at a temperature not below freezing and no higher than 40 degrees. Most home refrigerators will cool between 40 degrees and 45 degrees, which is OK. If you use a refrigerator, be sure not to store any apples or other fruits alongside your bulbs. Ripening fruit naturally gives off ethylene gas which will kill the flower inside the bulbs.
Don’t worry if you bought the bulbs early in the season and need to store them for several months before planting. Keep them chilling – even up to 16 weeks if necessary, until it is time to plant. Optimally, the bulbs should be put in the ground in December or early January, but can be delayed longer as long as they do not dry out in the cooling device or refrigerator. When it come time to plant, water well, include the potting soil when you plant, and protect with a layer of mulch to retain moisture and protect from heat. When bulbs do not receive sufficient weeks of cold treatment, they bloom too close to the ground, on too-short stems.