If you’re new to forcing bulbs and aren’t quite sure what on earth that is, you’re in the right place. Forcing bulbs simply means getting bulbs to bloom at a different time than they would if they were growing outside in nature — it’s an activity where we kind of trick the bulbs into thinking that winter is over (and it’s time to bloom!) before it actually is. Get ready to take your bulb gardening to the next level and enjoy blooms indoors all winter.
First Things First
There are three ways to “plant” or force bulbs indoors, and we’ll show you how to do both. And the types of bulbs you want to force may need a little bit of a different treatment than other types of bulbs — and we’re here to explain that difference, too. Understanding and paying attention to these details from the beginning makes forcing bulbs so much less complicated…and so much more enjoyable!
How to Chill Your Bulbs
Flowering bulbs come in two categories for forcing — those that need chilling time. (that mimics winter) to bloom, and those that don’t. Here’s a popular method for how to chill the bulbs that need it. Read this first, then refer to the next section to choose your bulbs based on their chilling requirements.
- If you live in an area where the fall temps hover around 40 degrees, you can try chilling bulbs outdoors and let nature do the job for you.
- One method is to place bulbs in a pot with potting soil, then burying the pot in a pile of leaves that is then covered with mulch or a tarp for protection.
- Check the moisture level in the pot every couple of weeks, and water accordingly. Aim for moist but never soggy and let the soil dry slightly between waterings.
- One method is to place bulbs in a pot with potting soil, then burying the pot in a pile of leaves that is then covered with mulch or a tarp for protection.
- If you’d prefer to chill indoors — your outdoor temps are simply too unpredictable or they get really low (15 degrees), for example — just gather your bulbs and place them in a paper bag and store them in one of these locations, aiming for consistent 35-55 degree temps:
- Refrigerators: Chill bulbs away from fruits, especially apples — fruits release ethylene gas as they ripen, and this gas can inhibit flower development inside the bulb. The extra refrigerator in your basement could be ideal for bulb chilling!
- Other locations for indoor chilling, including root cellars, unheated basements/attics/garages, and sheds.
- Refrigerators: Chill bulbs away from fruits, especially apples — fruits release ethylene gas as they ripen, and this gas can inhibit flower development inside the bulb. The extra refrigerator in your basement could be ideal for bulb chilling!
- Whichever method you choose for chilling, check your bulbs periodically but more frequently as you near the end of the chilling time for that bulb type. You’ll know the bulbs are ready to remove from chilling when you see thick white roots at the bottom of the bulbs, and 2-4” of stem growth. Don’t rely on stem growth alone, however — it’s the root mass that’s important for future growth and blooming. If you're unsure if roots are ready, just pop a bulb out and have a look. You won't hurt it.
- When the bulbs are done chilling, move them to a dim, warmer (about 65 degrees) inside the location to transition them for blooming. After about a week, move them to a brighter area. Within 2-4 weeks, you’ll see buds forming — and your flowers will pop soon afterward.
Bulbs for Forcing
As we mentioned above, some bulbs require chilling for forcing, while others don’t. And within the group that does need chilling, the chilling times vary depending upon what type of bulb you are forcing. Here’s a handy reference for what bulbs fall into each category, as well as the chilling time required for each type of bulb.
Bulbs that require chilling
| Bulb Type | Chilling Time | Time Until First Bloom |
| 6-8 weeks | 2-3 weeks | |
| Anemone | 8-10 weeks | 2-3 weeks |
| Crocus | 8-10 weeks | 2-3 weeks |
| Snowdrops (Galanthus) | 10-12 weeks | 2-3 weeks |
| Scilla | 10-12 weeks | 2-3 weeks |
| Hyacinth | 12-14 weeks | 2-3 weeks |
| Daffodil (non paperwhite) | 12-15 weeks | 2-3 weeks |
| Tulip | 10-16 weeks | 2-3 weeks |
Bulbs that do not require chilling
Paperwhite narcissus, amaryllis, and freesias do not require chilling. Any bulbs you purchase in the fall will be ready to plant and grow immediately. Simply place both amaryllis and paperwhites in a paper or mesh bag and store them in a cool, dry, and dark location until you’re ready to plant them, using one of the three methods outlined below.
Planting Methods
You’ve chosen your bulbs, determined if they need chilling or not, and you’ve decided how you’re going to chill them. Now you need to decide how you will plant them so you can begin to enjoy their gorgeous blooms and scents indoors. Here are a couple of traditional methods to choose from:
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Growing in water: Nothing could be easier than forcing bulbs in water, but the container shape is the key to success here. Traditionally, clear glass containers with an hourglass shape are used with this method. Fill the bottom of the glass container with fresh water, then place the bulb on top with the roots facing downward. The hourglass shape of the container allows the bulb’s roots to grow into the water while holding the bulb itself above the water. Simple and dramatic! Hyacinth, amaryllis, and narcissus are examples of bulbs that respond well to forcing in water.
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Growing in soil: Most other bulbs prefer this planting method. Plant the bulbs about an inch apart, the tip end up, leaving a good ½ - 2/3 of the bulb surface exposed above the soil. Planting too deeply or completely covering them up can easily lead to rot. Water in after planting, aiming for moist but not soggy, and check soil moisture regularly.
- Growing in pebbles/gravel: Take a shallow bowl without a drainage hole, and fill it with natural gravel, aquarium pebbles, or glass pebbles. Nestle the bulb into the gravel so the bulb is stabilized, then fill the bowl with water until it reaches the bottom of the bulb. Remember, just as with the water method, you don’t want the bulb submerged in water — your goal is for the roots to have access to the water while keeping the rest of the bulb above the water. Top off the water every couple of days to maintain that level.
How to Maintain Your Forced Bulbs Indoors
So, now that you have blooming bulbs indoors (congratulations!), here are a few tips for keeping them healthy and prolonging their bloom:
- Keep plants out of direct sunlight.
- Keep plants away from drafts and heating vents.
- Keep the soil moist but not soggy for potted bulbs.
- Refresh or replace the water to just below the bottom of the bulb for water-grown bulbs.
- Do not fertilize.
- If your blooming bulbs have stems that are top-heavy and flopping over, try wrapping the stems together with a festive ribbon or raffia tie.
- When the chilled bulbs are finished with their blooming, it’s not likely they will rebloom, so you can go ahead and move them to the compost pile. Non-chilled bulbs like paperwhites and amaryllis may be replanted outside in zones 8 and higher after they’ve bloomed indoors, but be aware that they may not bloom again for another two years.
- Just as with outdoor planting, if you want a steady stream of forced bulbs for the holiday or winter season, simply chill/plant your bulbs at regular intervals in the fall.
How to Make Your Amaryllis Rebloom Indoors
You can get your amaryllis bulb to rebloom indoors, but it does take a few steps. Check out our blog post here with instructions for helping your amaryllis rebloom.
Once you’ve forced bulbs indoors, it’s a fairly easy process to remember — and one that brings extra cheer, color, and scent into your home during the months when you’re dreaming about spring.