Forcing bulbs to flower indoors is a simple way to enjoy blooms any time of year. Options include tulips, paperwhites, amaryllis, daffodils, muscari, and more. Use the timing calendar to get flowers right in time for the holidays.
If you are new to bulb growing, these tips are for beginners.
Grow Flowering Bulbs Indoors
While you can grow bulbs indoors at home anytime, it’s most popular during the cold, dark winter months when we’re craving the beautiful pops of color that flowering bulbs can provide.
These tips share everything you need to grow bulbs in average household conditions and “force” them to produce flowers. Really, for this purpose, growing and forcing are the same thing since we grow them specifically for the blooms.
What Is Forcing?
When we “force” bulbs indoors we provide the conditions needed to trigger blooming. It’s the same things they need for outdoor flowering.
Depending on the type of bulb, this may be a period of cool temperatures followed by light, water, and warmth—but done intentionally instead of waiting for nature to do it.
Not only can you cause the bulbs to flower indoors, but, with some planning, you can make them come into bloom for a specific holiday like Christmas or Thanksgiving.
Let’s get started.
Contents
- Bulbs That Flower Indoors
- How To Chill Bulbs
- Forcing Bulbs In Water
- Forcing Bulbs In Soil
- Forcing Bulbs For Holidays
- Frequently-Asked Questions
- Resources
Bulbs That Flower Indoors
There are all sorts of options for indoor flowering bulbs and they fall into two basic groups: bulbs that require a chilling period before flowering and those that do not.
Warm Climate (Tropical) Bulbs
The two bulbs that do not require chilling and can be planted right away are amaryllis (Hippeastrum) and paperwhites.
If you are not a fan of strong scents, avoid paperwhites. While incredibly beautiful, they have a really powerful scent that is overwhelming to some.
Hardy Bulbs
These are cold climate bulbs, the same ones we plant outdoors in fall for spring flowers. The list includes classics like crocus, daffodil (Narcissus), Dutch iris, tulip, and scilla. I’ve listed all of them here.
Hardy bulbs marketed for indoor growing may already be pre-chilled by the seller. The label may say “pre-chilled” or “ready to plant indoors.”
If not, you can easily chill them yourself using the instructions below.
Size & Time Matters
The larger the bulb, the larger the flowers. Amaryllis is a prime example. Those blooms can be big (6-inches wide) and some varieties produce multiple flowers on one stem.
The advantage with smaller bulbs like crocus, hyacinth, muscari, and mini daffodils is how quickly they bloom. If you’re late getting forced flowers underway for the holidays, if already pre-chilled (by you or the seller), these guys can bloom in just 2 to 3 weeks.
If bulbs do not receive sufficient time to chill or it extends too long, they may not grow as expected. This could result in fewer leaves, a leggier stem, or no blooms.
New to bulb growing? These tips will help ensure you are starting with healthy, viable bulbs.
How To Chill Bulbs
If your bulbs come “pre-chilled” you can skip the chill period and plant according to the instructions on the label.
If chilling needs to be done, you can do this with the bare bulbs in a paper bag or plant them in containers first and chill the whole thing.
These times are general estimates: always check your plant label for specific info.
| Name | Chill Period | Weeks to Bloom After Planting |
|---|---|---|
| Anemone (Anemone coronaria) | 6 weeks | 6-8 weeks |
| Crocus (Crocus vernus) | 15 weeks | 2-3 weeks |
| Checkered Lily (Fritillaria meleagris) | 13-15 weeks | 3-4 weeks |
| Daffodil (Narcissus) | 15-17 weeks | 2-3 weeks |
| Dwarf Iris (Iris reticulata) | 15 weeks | 2-3 weeks |
| Dutch Hyacinth (Hyacinthus orientalis) | 12-15 weeks | 2-3 weeks |
| Grape Hyacinth (Hyacinthus armeniacum) | 8-15 weeks | 2-3 weeks |
| Tulip (Tulipa) | 14-20 weeks | 2-3 weeks |
| Siberian Squill (Scilla siberica) | 6 weeks | 2-3 weeks |
| Snowdrop (Galanthus nivalis) | 15 weeks | 2 weeks |
| Amaryllis (Hippeastrum spp.) | not required | 6-8 weeks |
| Paperwhites (Narcissus tazetta) | not required | 3-5 weeks |
Indoor Chilling
The goal is to keep the bulbs dry in darkness at the right temperature for the required period of time shown in the chart (above).
The general temperature range for an assortment of bulbs is 35 to 45°F (2 to 7°C).
Keep the bulbs in a paper bag that will both absorb moisture and allow some air flow.
If you have room, the fridge or a cold room is a good option.
Outdoor Chilling
As mentioned, you can either chill your bulbs in paper bags or plant them in containers and chill the whole container.
The main concern with outdoor storage is to be careful the bulbs are not exposed to frost and freezing and do not get eaten by mice or squirrels.
Any protected space like a shed or garage with temperatures between 35 to 45°F (2 to 7°C) could work.
If your climate is like ours, temperatures may toggle in and out of range, but, if they are in the right temperature range for much of the time, they should be fine.
Put a reminder in your calendar or phone to follow up with planting when the chill period is done.
Forcing Bulbs In Water
- Recommended for: amaryllis, hyacinth, narcissus.
Supplies
- Forcing jar, mason jar, or other suitable bowl or vase
- Marbles or stones to prop up bulb (if needed)
Tips
The idea with forcing a bulb in water is to suspend the bulb above water so just the lower third (or a bit less) of the bulb is submerged. This is where the roots are.
You don’t want to submerge anymore than necessary to facilitate root growth because most bulbs do not like prolonged water exposure and will rot.
The old-fashioned and easy way to force in water is to use a forcing jar. These are specifically designed for bulbs like hyacinth and just the right size to hold the bulb nicely in place with water just at root level.
Alternatively, you can use just about any jar or container that will allow you to provide the same setup.
Sitting the bulbs on stones or marbles is fine too so long as the roots get water.
Care
- Keep your forcing jar in indirect light.
- Check to be sure the water does not evaporate and dry out the roots.
- Change the water every 2 to 3 days.
- No fertilizer is required.
- When there are a few inches of roots, you can move your bulb to a sunnier location to accelerate flowering.
- Once the flower is opening, go back to indirect light, away from drafts or heat vents, to extend the bloom time.
Forcing Bulbs In Soil
- All of the bulbs listed above can be forced in containers with potting mix.
Supplies
- Flower pot with drainage holes
- Saucer
- Potting mix
- Moss (optional)
Tips
Choose a container with drainage holes that suits the appearance, size, and quantity of the bulbs you are growing.
The bulb product label will list the recommended planting depth. Large bulbs like amaryllis can be planted with 1/3 of the bulb above soil level. Smaller bulbs like snowdrop and crocus can be submerged so just the very tops of their pointy tips are showing.
For pot depth, it should be at least two bulb lengths deep to allow room for root growth.
For spacing, we can get away with more crowding than you might when growing outdoors in the ground because it’s just for one blooming season. The important part is to ensure the base of every bulb has exposure to moist potting mix.
Larger bulbs like amaryllis will need a weighty container to anchor the whole thing down. Otherwise the plant may tip over once it gets top-heavy with it’s large blooms.
Before planting, you can give your bulbs a head start by sitting the base of the bulb (where the roots are) in a shallow dish of warm water to start hydrating the roots for an hour or so.
Moss is optional but always give a nice, earth look.
Care
- Keep your potted bulbs in indirect light while roots are forming.
- Water as needed, never allowing potting mix to dry out.
- No fertilizer is required.
- Once growth is evident, move the container to a sunnier location to encourage blooming.
- Once the flower is opening, go back to indirect light, away from drafts or heat vents, to extend the bloom time.
Forcing Bulbs For Holidays
See Resources to save a copy of these forcing calendars.
If you want your bulbs in bloom in time for a specific date or holiday, just count back the number of weeks they need to chill and bloom to know when to get them started.
Here are a few examples.
Paperwhites
If you want paperwhites in bloom for Christmas and New Years, plant them by mid November.
They will come into bloom by mid December and should stay in bloom for a number of weeks.
Start a bit later and you’ll have the buds about to unfold which I find equally beautiful.
Amaryllis
To prepare an amaryllis—specifically one that takes 6 to 8 weeks to bloom—for Valentine’s Day, get it planted by mid December. It should be in bloom in early February and stay in flower for a few weeks.
Alternately, start it a little later and let the recipient have the joy of seeing the blooms unfold at home.
Waxed Amaryllis
You can also buy amaryllis bulbs that have been coated in wax. The idea is that the wax coating will maintain the moisture within the bulb for the duration of the blooming cycle so other soil or water is required.
These waxed bulbs have their basal plates removed (the area where roots grow out the bottom). Sometimes a coil of wire is attached to the base to prevent the bulb from tipping. To grow it, you just leave it on a table top and let it do its thing.
Will it bloom again? I’ve heard mixed reviews on this. Some gardeners report removing the wax after blooming and successfully regrowing the bulb. Others report the entire waxing method seems to leave the bulb completely depleted. I imagine you have to judge based on how yours looks when the flowers are done and try storing and regrowing if you like.
Crocus
If you want crocuses in bloom indoors in March and they are not yet prechilled, count back 18 weeks (=early November) to find the date they should start chilling. This allows 15 weeks for chilling and 2 to 3 weeks for blooming.
Frequently-Asked Questions
The time it takes to force bulbs varies from weeks to months depending on type and forcing conditions including light, humidity, temperature, and water.
Forced bulbs do not require fertilizer. The bulbs contain all the energy needed for the bloom cycle.
Some bulbs can be forced more than once, others cannot. Your product label should say if this is possible.
Some types of bulbs are good for one spectacular indoor blooming cycle and no amount of care is going to make it happen again.
Others may have more life in them.
Generally, a hardy bulb forced in potting mix is more likely to regrow than one forced in water.
If you are saving bulbs after forcing, be sure to allow the post-flowering phase to take place first. This is when the leaves, through photosynthesis, give energy to the bulb for future growth. The cycle is complete when the leaves have withered and died off. At this point the bulb can be removed from its soil or water and stored in a cool, dry place until planting time.
If you are switching from indoor to outdoor growing, double check that the bulb will not be invasive in your garden.
And yes, hardy bulbs will need a fresh chilling session before each blooming cycle.
Resources
Free Printable
Empress of Dirt
When To Force Bulbs Indoors
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How to Force Bulbs Indoors
Equipment
Supplies & Materials
- 1 Amaryllis bulb or other bulb
Instructions
- Sit base of bulb in warm water for one hour before planting to hydrate the roots.1 Amaryllis bulb
- Place enough moistened potting mix in the flower pot to support the bulb so the top third will sit above soil level.
- Place the bulb bottom (flat end) down on potting mix.
- Add potting mix around bulb leaving top third above soil level.
- Water thoroughly and replenish potting mix as needed.
- For next few weeks, keep at room temperature (70F / 21C) away from direct light until roots have formed and leaves start to appear.
- Water as needed.
- Then move to a sunny location for flowering.
Lee says
Thank you for the thorough and easy to understand directions, I’m going to give it a try!