Forcing Bulbs Indoors For Winter Blooms: How-To & Tips
Imagine the dreary months of January and February…dull, bleak, windy…brrrr.
Here’s a lovely way to add a touch of Spring inside the home: Prepare bulbs ahead of time to bloom indoors during these cold, snowy months. It’s easy to do too!
Understanding How It Works:
Flowering bulbs like Tulips need to be planted in the Fall so that they can experience cold temperatures and a period of dormancy during the winter season. Once it begins to warm, they know Spring is near and start growing their shoots to the top of the soil that will then produce their colorful petals.
Many won’t perform until they first experience this chilling period. Forcing has to accomplish this same experience:
- Give them a “season” of cold so that they think Winter has arrived.
- After a few months of being chilled, bring them inside the house to experience the “season” of warmth–they’ll think Spring has arrived and will begin to grow.
Here’s How To Do It:
- Choose well draining pots so that the bulbs won’t rot and they can be transported easily inside the house to a warm, sunny location.
- Cover the bottom with gravel to support good drainage then top up with potting soil.
- Position the preferred amount of bulbs on top of the soil with their pointy sides up and the root side down. There’s no need to space them as when planting in a garden, just make sure that no two are touching each other or the sides of the pot.
- Then cover them with some potting soil leaving the top tips exposed.
- Water thoroughly then allow to drain.
- Place in a cold, dark location like an unheated garage or garden shed–somewhere chilly but doesn’t drop below freezing (the rooting process will stop if they freeze). If there’s room to spare in an old refrigerator, you can do them in there too (ideal but watch the soil moisture, will likely need to water regularly). Some will dig a trench outdoors to hold all the pots until it’s time to bring them in. Dig the trench about 2 feet deep and as wide as needed to hold everything. Cover with a good layer of straw and leaves to give them some protection (about a foot deep in harsh zones).
- If positioned somewhere inside, occasionally give a drink with cold water so that the soil doesn’t dry out completely, don’t give too much though, just sparingly. If they were left outdoors, doing this once a month should be sufficient.
- Let them chill for about 13 to 15 weeks. When they’re ready to be moved indoors, you will see roots in the drainage holes at the bottom of the pots or new stem growth at the top that’s about two inches high.
- When it’s time to bring them inside, transition them first by putting them in the coolest room you have (with some light). Water thoroughly once you bring them in. After a few days you should notice some new plant growth, once you do you can move them to a warmer and sunnier location inside the home.
- For the next two to three weeks you’ll notice the shoots growing and then starting to blossom.
Varieties That Work:
- Tulips: Can require at least 15 weeks of chilling to be successful. Early flowering varieties are easier, some suggestions: Beauty of Apeldoorn, Apricot Beauty, Monte Carlo, Oxford, Mariette, Aladdin, Maytime, Diana, Brilliant Star.
- Hyacinths: Wait until the top is about 3″ before moving to a sunny location. Usually requires at least 10 weeks of chilling to be successful. Varieties to try: Pink Pearl, Delft Blue, Anne marie, Carnegie, Hollyhock, Amethyst.
- Daffodils: Usually requires at least 13 weeks of chilling to be successful. Varieties to try: Carlton, Cheerfulness, Flower Drift, Ice Follies, February Gold, Fortune, Dutch Master, Easter Joy, Geranium, Golden Bells, Jetfire. Place in direct sunlight after being forced.
- Crocus: Can require up to 15 weeks of chilling to be successful. Some varieties to try: Remembrance, Giant Yellow, Jeanne d’Arc, Peter Pan, Flower Record, Pickwick.
- Iris: Can require up to 15 weeks of chilling to be successful. Dwarf Irises perform well for this.
- Paperwhite Narcissus: See details below.
- Time results for special events such as Christmas, Valentine’s Day, New Years, etc. Plant in pots approximately 15 to 17 weeks before needed.
- They won’t likely force successfully again next year, but plant them in the garden in the Spring once they’re done and have died back–they may give blooms after a year or two in the garden.
- The best time to purchase bulbs is in early Fall, it’s harder to find a good selection later in the season.
- Stagger the bloom times by planting and bringing out each pot about 7 days apart from each other.
*First published October 12, 2009 and moved to this page for better organization
From the daffodil family, these are one of the easiest to force and they don’t need to be chilled first like others do. Directions:
- Choose a container that’s at least 2 inches deep and large enough to hold the amount to plant. Fill the container with a layer of pebbles or glass marbles leaving a space of at least one inch at the top of container.
- Arrange each bulb on top of the pebbles with the root side down then cover with more pebbles until they are secured in place (covered about 1/3 of the way up). No need to worry about spacing with this method, fill the container with as many as you like without letting them touch each other.
- Next, fill the container with water until the level reaches just beneath the bottom of the bulbs. You don’t want them fully submerged as this will cause them to rot. By having the level very close to the bottom like this, the roots will be drawn down into the water.
- Encourage strong root development by placing the container in a cool dark place for about 2 weeks. You should also notice new plant growth at least an inch or two tall. After 14 days move the container to a bright location.
- Make sure to watch the water level, keeping it just underneath at all times.
- They will begin to bloom between 4 and 6 weeks and should last about half a month. Once they have faded, they will not be able to rebloom.
Good To Know: For displays of continuous blooms, prepare a new pot every 10 days or so.