Forcing hyacinth bulbs is a great way to enjoy beautiful blooms in early spring. Hyacinth bulbs must experience cool temperatures to bloom properly. This cold period tells the undeveloped flower hiding inside that spring is coming and it should begin to grow. The process of simulating winter to prompt a plant to bloom indoors, and earlier than normal, is called forcing. With a few tricks, you can make your bulbs think that winter has come and gone.
Forcing Hyacinth Bulbs Indoors
Chill Hyacinth Bulbs for 12-16 Weeks
Hyacinth bulbs can be chilled planted or unplanted. The following directions will work whether they are in pots or not. If you choose not to use a pot, store the bulbs in a mesh bag. For a potted bulb, follow the potting directions found below. Always wear gloves when handling hyacinth bulbs. They contain oxalic acid which can cause a reaction or skin irritation.
Hyacinth bulbs need 12 to 16 weeks of chilling. During that time, they must be kept at a consistent 35 to 48 degrees F (1.7 to 8.9 degrees C). They need a cool, dark place with some ventilation. Chill them in a cooling refrigerator, an unheated garage, basement or attic. A consistent temperature is necessary, so use a cooler thermometer to track the temperature.
As you track the temperature, check the soil as well (if they are potted). Water them sparingly – the soil should be moist, not soggy. Do not chill hyacinth bulbs in the same place as fruit, especially apples and pears. Ethylene gas emitted by ripening fruit damages the bulbs.
Give Hyacinth Bulbs Light When They Sprout
If the bulbs start to sprout, begin the warming process. If they have not been potted yet, do so once they sprout. If they have not yet sprouted, pot and begin warming the bulbs after the 12-to-16-week cooling period.
Hyacinths need time to acclimate to heat and light. You must gradually increase the temperature and exposure to light. Move them to mild indirect sunlight, then to a slightly sunnier spot and so on until they are in full sun.
Potting Forced Hyacinth Bulbs
Whether you plant them before or after their cooling period, the potting process is the same. Most importantly, very good drainage is a must. A hyacinth in wet soil will develop root rot and the root system will turn mushy. Be sure that excess water drains away from the plant. Browning leaves and petals are signs of too much moisture.
When planting several bulbs at a time, space them three to four inches from each other so the roots and flowers have room to grow. Select a potting mix that drains well and supports the top-heavy plants from tipping over. Use a pot with a hole on the bottom and place a broken pot shard over the hole to prevent the soil from seeping out.
Steps for potting hyacinth bulbs:
- Put some potting soil into a bucket, add water and mix until evenly moistened but not soggy.
- Put two to three inches of the mix in the container and set the bulbs on top, pointy-end up.
- Cover the bulb with potting mix, but if the bulb has sprouted, do not completely cover the sprout.
- Lightly tamp the soil and add more until the soil level is one inch below the rim.
- Water to settle the bulbs in place and to check the pot for proper drainage. If using a tray or saucer, empty it after the water has fully drained from the pot.
- Do not fertilize yet. As you move the potted plants, rotate them every so often so they will grow straight up.
Forcing Bulbs in a Hyacinth Glass
A clear hyacinth glass, or hyacinth vase, puts the plant’s growth on display to enjoy and study. This makes a great project for the whole family. The vase has an hourglass shape that allows the bulb to sit above the waterline. Hyacinth vases are available in garden centers that sell bulbs, or you can buy them online.
You can force bulbs directly in the hyacinth vase or you can chill them first, then move to the hyacinth vase. Chill the bulbs according to the directions above. Use a mesh bag if you are not chilling them in the vase. If using a vase follow these instructions:
- Fill the vase with water until just under the bulb. If there are roots, they should be in the water, but the water should never touch the bulb.
- Once there is an ample root system, begin introducing them to more sunlight.
- As the plant grows, turn the vase regularly so the plant does not grow to lean toward the light and topple the vase. Keep the water level consistent so the roots never dry out.
Forced Hyacinths Take 2-3 Weeks to Bloom
The bulbs will flower about two to three weeks after they sprout. Once the flowers are full of color, you can move the pot or vase wherever you’d like to get the most enjoyment from the flowers and fragrance. After flowering, place them back in a sunny spot and allow the bulb to grow. The flowers last about two weeks.
The hyacinth’s bright blossoms and sweet fragrance have made them a favorite of gardeners for over 400 years. If you continue caring for your hyacinth, you can enjoy these perennials year after year. If you loved forcing hyacinths, paperwhites are another bulb that will force easily