Forcing spring bulbs

Forcing Spring bulbs

It’s nice to have a pot of blooming bulbs in the dead of winter to remind us of the promise spring yet to come.

Many bulbs can be forced to grow indoors in the winter. Spring bulbs such as; daffodils, hyacinths and tulips are the most popular but others like crocus, squill, grape hyacinth and Dutch iris can also be forced for indoor bloom.

Potting bulbs
When forcing tulips, make sure the bulbs are firm, free from soft spots, white mold, cuts and bruises. Fill the container 3/4 full with a well-draining potting soil mix and place the bulbs close together with pointed tips up and flat side facing out. The tips of the bulbs should be 1 inch below the top of the container. This allows room for root expansion and easier watering. Fill in additional soil mix around the bulbs and water well until it drains from the bottom. A 6 inch pot will accommodate 5-7 tulip bulbs, 3 hyacinths and 6 daffodils. Cover the container with plastic to keep the soil slightly moist during this cool period (optional). Be sure to mark your containers with the planting date.

forcing tulip bulbs

Chill time
Chill the potted tulip bulbs in a cold basement, cellar, garage or refrigerator at 35-48F for 12-16 weeks. Cold treatment is varies according to type of bulb: on average, Daffodils require 12-13 weeks, hyacinths 10-14 weeks and smaller bulbs (grape hyacinth, crocus) 8-9 wks. Not enough chill time can produce short, distorted flowers. If storing bulbs in the refrigerator be sure there are no fruits or any other vegetation that emit ethylene gas as this can damage the flower inside the bulb.

Forcing bloom
The trick is to fool the bulbs into thinking that winter is over and its time to start growing.
After the cold treatment, check for white roots at the bottom of the pot and new top growth. Slowly, bring the container to warmer temperatures (55-70F) and indirect light and start watering. Once exposed to sunlight, the light yellow/green shoots should start to green up and grow. From this point on, it should take 2-4 weeks to bloom.

Flowers will last 10-14 days depending on temperature and sun exposure. The cooler the temperatures the longer lasting the flowers will be. Avoid exposing the flower to direct sun.
If you stagger planting time every two weeks and you will have flowers throughout the better part of winter.

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