Winter gardening technique: Forcing bulbs to bloom indoors

SALT LAKE CITY — Winter can feel a bit dull for gardeners since there’s not much reason to be outside doing yard work. There is one thing, though, that can help keep you busy if you’re a hobby gardener: forcing bulbs.

Forcing bulbs is a technique that can trick spring bulbs into blooming even in the winter. It can work with any spring bulb, but daffodils, crocuses, and tulips are some of the easiest to work with.

According to KSL Greenhouse Host Taun Beddes, the process can take anywhere from 10 to 14 weeks, depending on the variety and species.

The pre-planting method

One method is to preplant everything in the pots in which you plan to grow your bulbs. 

“You can actually get bulb-forcing pots. They’re a little bit more squat,” said Beddes. “But you can use almost any pot as long as it’s deep enough.”

Here, deep enough means the pot needs to be at least 6 inches deep. Once you find a decent-sized pot, place the bulb so that the top quarter is sticking out of the soil. Then, place it somewhere that is 35 to 40 degrees Fahrenheit.

The cover method

Another method is to cover the pots with a light Reemay fabric like a weed barrier.

“Cover them in 6 inches of mulch, something like a bark mulch or peat moss, so that they don’t freeze,” said Beddes. “Do that against a building where they’re protected.”

The next step is to uncover them and bring them inside. Let them grow at around 60 degrees Fahrenheit until they’re ready to flower before placing them wherever you would like.

What’s next?

“Force them, let them grow, and then just take the whole chunk of bulbs out because they’re going to be rooted into the soil, and just plant them in the spring when they’re done blooming,” said Beddes.

Another option is to let them continue to grow even after they finish blooming. And when they go dormant, you can pull out the bulbs and replant them then.

If you don’t have much space, you can put the bulbs into Ziploc bags with moist potting soil. The moistness level of the soil should be similar to that of a wrung-out sponge.

“You leave them in the fridge for that same amount of time, and then you prepare your pots and plant them after the fact so that you could have your soil in pots not already filled,” said Beddes. “But after you’ve waited the necessary time, pull those bulbs out and plant them according to this fact sheet.”

Keep in mind that bulbs should always be in areas that stay above freezing and below 40 or 45 degrees Fahrenheit.

Read more from the KSL Greenhouse show:

• How to successfully care for an amaryllis
• Preparing for garden season: Seed catalogs 101
• Time to order tomato seeds

KSL Greenhouse is on every Saturday from 8 a.m. to 11 a.m. Follow the show on Facebook, Instagram, and YouTube. You can also find more gardening info at our linktr.ee.