ANN ARBOR—To bring a flash of color and hint of spring to dark winter days, prepare bulbs now for indoor blooms. Bulbs generally planted or left in the ground outdoors during the winter months can be forced to bloom indoors if planted now.

“These bulbs should be planted from mid-October to early November,” says Adrienne O’Brien, a senior horticulture assistant at the University of Michigan’s Matthaei Botanical Gardens. “Plant them in a sterile packaged soil mix of mostly peat and perlite.”

A six-inch pot with five tulip bulbs will need a minimum of 14 weeks of cold treatment to produce colorful blooms inside while snow and winter winds howl outside.

Once the bulbs are planted in pots, the containers should be placed in an unheated garage or shed, in the crawl space under a house or in an unheated attic. A coldframe or window well will also work well,” says O’Brien, as will a balcony or porch if the pots are placed inside a heavy box that is heavily insulated and placed right next to a house.

“The pots should be watered only when the surface of the potting medium begins to dry out and the pot feels much lighter,” says O’Brien. “The soil should not completely dry, as the roots will be damaged. Check them weekly for the first month and less often later on. If over watered, the bulbs will rot. There should be roots at the bottom of the pots by late November, especially the tulips and daffodils.”

When bringing the bulbs indoors from cold storage, first put them in a cool place out of direct sunlight. Foliage will already be growing. “If the foliage is frozen, don’t touch it,” O’Brien says. “After a day or two, the pots can be moved to a brighter area. The cooler and brighter the conditions, the better. Plants will be more compact and have better quality flowers which will last longer.”

When the buds begin to show color, they will open in a day or two. The blooming process can be slowed at this point by placing the pots in a cool (40-50 degrees) area for several days. Under ideal conditions, flowers will last a week to 10 days.

“It is not a good idea to try to speed up the blooming process by moving the pot to a warmer area as inferior foliage and blossoms will result,” says O’Brien.

After the flowers have died, there are a couple of options for the grower. The bulbs can be thrown out. They cannot be forced again. It may not be worth the time and effort to save them and plant them outside. “Do not feel guilty if you decide to toss them,” O’Brien says. “You may keep the potted bulbs inside until it is warm enough to put them outside, mid to late April, in a protected area.”

Continue watering the bulbs regularly until the foliage begins to die. After all the foliage is gone, remove the bulbs from the pot and put them in a paper or mesh bag in a dry area until fall when they can be planted outside. “You may get flowers the following spring,” O’Brien says, “but it will probably take two seasons for the bulb to recover. I do not recommend saving tulips—they divide into much smaller bulbs and take longer to recover.”