Common Problems While Forcing Bulbs Indoors

Houseplants are all the rage lately, and we can see why! Lush greenery in your home adds a cozy feel; plus for people who live in colder climates, plants can lift up your moods through the darker winter months.

There’s no reason to limit yourself to only foliage houseplants—forcing bulbs to grow indoors means you’ll have colorful blooms inside your home! It’s a pretty simple process, though over the years, we’ve heard from folks who mention common problems they’ve run into while growing bulbs indoors, so we wanted to address those problems here.

Bulbs grown indoors at temperatures above 70°F will have blooms that won’t last long.

Problem 1: Leggy Plants

There are two types of spring-flowering bulbs: those from colder parts of the world that require vernalization (the winter hibernation that promotes the bulb to flower) and those from warmer parts of the world that don’t need a chilling period. 

Both of these types of bulbs share one common problem when being grown indoors: if not provided with adequate light, they stretch, growing taller and taller as they reach for more sun. The same would happen if you were to grow sun-loving bulbs in the shade outdoors. They would grow leggy and flop over. 

In nature, many bulbs grow in full sun, and they don’t have to stretch for extra light. Forcing these bulbs indoors is equivalent to growing them in heavy shade. The solution is to provide the bulbs with more light.

Simply placing them closer to the window still won’t be enough. Instead, you should place a cool light source, like an LED or a cool fluorescent bulb, a foot above the bulb. Add the light as soon as the plant starts to emerge from the soil. 

It’s important to use a cool light source for bulbs because the blooms will last longer. Warm light shortens the length of bloom time. 

Problem 2: Bulbs Not Rooting

A problem we often hear from people trying to force bulbs that don’t require cooling, like Paperwhites, is that the bulbs aren’t making roots. 

This often happens when people try to grow bulbs in water. While it is possible to grow Paperwhites in water—and it has to be cool water—it’s not ideal. You’re better off growing them in soil.

The soil temperature should be between 50 and 60°F. Any higher than that, and the bulbs won’t root well. 

Problem 3: Short-Lasting Blooms

Blooms last longer if the plant is grown in a cooler environment. That’s why we say to use only cool bulbs when providing a light source while forcing bulbs indoors.

Most people keep their homes warmer than what’s ideal for bulbs. Bulbs grown indoors at temperatures above 70°F will have blooms that won’t last long. If you do keep your house on the warmer side, then you should move your bulbs to an area in your home that’s cooler. You can always move them to put on display, but the majority of their time should be spent in a cool spot. 

Problem 4: My Bulb Didn’t Bloom!

Sometimes bulbs forced indoors don’t bloom at all. We’ve seen this often when people try to grow bulbs that are from colder parts of the world, and they didn’t realize they had to chill the bulb first. 

As mentioned above, many spring-blooming bulbs require a cold vernalization period. Early blooming bulbs have a shorter vernalization time than late bloomers. Since late bloomers require a longer chilling period, they are more difficult to force indoors than early and mid-season bloomers. 

For bulbs that require a chilling period, plant them in soil that’s 50 to 60°F, then place the pot in a fridge that doesn’t have fruits or vegetables in it—fruits and veggies release ethylene gas that can cause bulbs to abort their blooms. Consider putting your bulb pot in a beer fridge or in an area that stays uniformly cool, about 35-40°F. 

If bulbs don’t get enough cooling, they won’t fully develop. Instead, you might just have leaves but no blooms. 

You can also pre-cool the bulbs dry, rather than putting them in a fridge after you pot them. You can either put them in the fridge yourself—make sure to order early so we don’t sell out of your favorites!–or you can order pre-chilled bulbs. We ship these out around December; then, you can just directly root them rather than worrying about chilling the bulbs yourself. 

It’s also important to know which bulbs are best for forcing indoors. In general, choose compact bulbs that grow shorter stems. Some bulbs like Alliums, which bloom in very late spring, just won’t bloom indoors. We can’t fool them into thinking they’re ready to bloom! That’s all forcing blooms really is—tricking Mother Nature.  

When the risk of hard frost has passed, you can plant your bulbs outside as a way to “repurpose” them. Make sure to plant the whole clump rather than pulling them apart. You can leave them there to bloom in the following years. It may take some time for them to recharge, but then the bulbs will be back to normal again and can continue adding beautiful color to your yard.

If you’re having any other trouble forcing bulbs, let us know, and we’ll let you know the best solution!