How to Grow Bulbs in Forcing Jars

Forcing bulbs means tricking them into blooming early in pots of soil, bowls of pebbles or forcing jars of water. Most bulbs grow only in soil but "both hyacinths and crocuses can be grown in water alone if you use the special glass vessels made just for this purpose," say the editors of Sunset Books in "Bulbs for all Seasons". These vessels are hourglass-shaped forcing jars that come in two sizes--large for hyacinth bulbs and small for crocus corms.

Instructions

1. Find forcing jars at garden centers or thrift shops. The large size is also known as a hyacinth vase. Wash and rinse them thoroughly before using.

2. Select crocus corms (commonly referred to as bulbs) or hyacinth bulbs in the colors you want. Choose Large Flowering Crocuses, Crocus vernus, instead of Species Crocuses.

3. Prechill the bulbs in paper or mesh bags in your refrigerator. Do not refrigerate apples and bulbs in the same drawer. Apples release ethylene gas that can damage the bulbs. Crocuses need to be chilled for 15 weeks and hyacinths need 12 weeks.

4. Pour water into each forcing jar and top with one bulb per jar, placing the pointed end of the bulb up. Adjust the water level so the water is close to, but not in direct contact with, the bottom of the bulb. Monitor the water cleanliness and level during the forcing process, and change or top up the water.

5. Move the jars to a sunny location indoors. Crocus jars prefer a 60 degree-room and hyacinth jars should be in a 70 degree-room. Roots will appear in the water. The crocuses will bloom in two weeks and the hyacinths in two to three weeks. Once they are flowering you can prolong bloom by removing them from direct sunlight.

Tips & Warnings

• After the blooms have withered, throw away the bulbs. They have worn themselves out blooming in water and are unlikely to grow again if you plant them outdoors.

• If your blooming hyacinth becomes top-heavy and wants to topple, simply slide wooden toothpicks into the sides of the bulb to brace it against the rim of the forcing jar.

• Wear gloves when handling hyacinth bulbs as the bulbs can irritate your skin.

References

• Bulbs for All Seasons; Sunset; 1990
• Sunset; The gentle art of forcing bulbs; Jim McCausland, October 2000
• International Flower Bulb Centre

Resources

• Brent and Becky's Bulbs
• John Scheepers Dutch Bulbs