How to Force Plant Bulbs to Grow

Paul James explains how to force tulips and narcissus to bloom when you want.

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Filed under: How To, Container Gardening, Flowers, Gardening

Ever wonder how florists get bursts of color from bulbs in pots? It's easy and something you can do at home without too much fuss. Gardening by the Yard host Paul James explains how to force bulbs.

Here, Paul uses tulip and paper-white narcissus bulbs. The tulips have a chilling requirement, the narcissus don't.

Figure A

Tulips

Fill a pot (with a drainage hole) within two inches of the top with a sterilized potting mix.

Stick eight or 10 bulbs in the mix with the flat portion of the bulb along the inside of the pot (figure A). When the plant grows and the flower appear, they'll turn out from the pot.

Add a bit more mix, but not enough to cover the bulbs completely.

Water well.

Now for the chilling: These tulips need temperatures of between 35 and 48 degrees F for about 13 to 15 weeks, and they must be kept in total darkness. You're tricking them into thinking they're growing underground. Paul suggests an unheated garage. Just place an empty pot over the one with the bulbs, and keep the soil moist but not soggy.

Once the tulips are up and growing — after about 13 weeks — place them in the house in a spot where they get indirect light and cool temperatures — the cooler the better.

Figure B

Narcissus

Fill a shallow pot (with no drainage) with perlite.

Add the bulbs. It doesn't matter which way you orient them.

Top with a layer of decorative stones, leaving the bulb tops exposed (figure B).

Fill the pot with water.

Though narcissus don't need to be chilled like tulips, it's a good idea to put them in a dark closet for about three weeks, or until they begin to sprout.

Narcissus grow great in standing water, and if they dry out they won't flower, so make sure to water them regularly.

Like tulips, once the narcissus has had its time in the closet, place it in the house in a spot that gets indirect light and cool temperatures.