Imagine that it’s wintertime. Anything verdant and green has long turned to brown. Limbs lie leafless. A few berries may yet hang on the shrubs. We’re already eager for spring, but the growing season is still months away. Wouldn’t this be the perfect time to enjoy bright red tulips, or the sweet aroma of blooming narcissus? If you want to enjoy these and other mid-winter flowers, now is the time to start forcing bulbs.
Pretty much any spring bulb can be forced. All we have to do is fool them into thinking that spring has arrived—in the middle of January. To do that, we have to plan ahead—up to 15 weeks ahead.
Most garden centers will have sold out of the popular bedding bulbs—tulips, daffodils, hyacinths and crocuses. If any are left, they’ll probably be a bargain, so grab them while you can. Remember that the bigger the bulb, the more flowers it will produce. Make sure the bulbs aren’t dried out, and be sure they haven’t started to grow.
But don’t despair if you can’t find these bulbs for planting. There are still options. Paper White Narcissus and Amaryllis are often sold as loose bulbs or a pre-planted kit, and they’re in the stores now. Even better, both of these don’t require chilling. Simply plant them in potting mix, water, and place them where they’re receive bright, indirect light. To avoid lanky, weak growth, Narcissus require a cool (60°F) spot, while Amaryllis do fine at normal room temperature. The time to bloom will vary according to the temperature, but estimate six weeks for Paper Whites and a bit more for Amaryllis.
Most bulbs do require winter chill before they burst into bloom. Happily, we have a place in our homes that has wintery conditions all year round—the refrigerator. You can simply place your bulbs in a paper bag, close it up, and stick them in the fridge (away from produce, such as apples, that emits ethylene gas, which would damage the flowers inside the bulbs).
This pre-chilling gets things going, but the bulbs will also need time in a pot to develop their root systems. Once the weather outside has dropped into the 40s, you can take them out of the fridge and plant them in a container filled with potting mix. Ignore the planting instructions that came with the bulbs—once forced, they aren’t likely to bloom again anyway.
The pot you choose should be at least twice as deep as the bulbs. Add potting mix until the container is half full, then place the bulbs so that their tips will just reach the top of the pot. Add more potting mix until the pot is comfortably full, leaving room for watering.
How many bulbs should you use? For a gorgeous show, cram the pot as full as possible, without letting them touch! Even better, use more than one type of flower for a living bouquet. Add the larger bulbs first, adding mix as needed to support the smaller ones at the right depth. For maximum impact, be sure to choose bulbs that bloom at the same time.
Water thoroughly, add a label so you remember what you planted (and when), and loosely cover with a paper bag. Place somewhere that stays between 35° and 48° F. to continue chilling. You can continue to keep them in the fridge (if you have room), place them in an unheated part of the house (the garage is fine), or move them outside (or even better, into a cold frame) with a thick, insulating blanket of dry soil and dead leaves or straw. Make sure they stay below 48°, but don’t allow them to freeze. Check regularly to see if the pots need more water. They should be damp, but not soggy.
This chilling period should last about three months. When you see roots coming out of the drainage hole and green shoots sticking up out of the bulbs, it’s time to bring them back indoors and warm them up. Make sure they have plenty of light, but direct sunlight, especially through a glass window, can burn the foliage and flowers. Blooms will appear in approximately three to four weeks, depending on the room’s temperature.
To prolong your show, move the pots back to a cool location at night, and keep them away from the heater vents.