By forcing bulbs to grow and flower indoors and you can enjoy blooming hyacinths, daffodil and narcissus species, tulips and other bulbs inside as early as the Christmas season or throughout the winter.Most spring flowering bulbs require a certain period of time to “chill” before it blooms this is called stratification. By supplying the ‘chill’ time artificially and out of season, we can force bulbs to bloom early and indoors. It is important not to shorten the length of the bulb’s required ‘chill’ time and this takes a bit of preplanning if you want the bulbs to bloom for a certain date like Christmas. Just count back from your desired date to allow enough time for both the ‘chill’ and growth periods required.
Dwarf irises and crocuses, require only about six weeks. Hyacinths prefer 12-15 weeks. Daffodil and narcissus species, as well as tulips, need at least 12 weeks but are better with at least 16 weeks. Half the time is for chill and the other half for growth. Start off with good healthy bulbs, making sure they have no soft spots, or mould. You can also look for bulbs that are already predetermined for forcing. These special bulbs will be well marked in their packaging and are often sold in complete kits with soil and a container.
Remember bulbs come with their nutrients inside their bulb, so your planting mix doesn’t have to provide nutrients, but it is essential that it has good drainage. Choose a container that has drainage holes or is a specialized vase made for forcing bulbs like hyacinths. A mix of 60% peat, 20% vermiculite, and 20 per cent perlite should do nicely. Layer the bulbs in the pot as tightly as you like. It is alright for them to touch. Fill your container with soil to the top of your container allowing some space for watering.
For chill time, you can use a refrigerator set at 40 degrees but remember to keep the bulbs watered. Also be sure not to allow any fruit to ripen in the fridge that has bulbs in it. The fruit releases ethylene gas, which is very toxic to bulbs. Other options include unheated garage, shed or cold frame or safe place outside protected from freezing and vermin. The basic idea is to give then dark and cold (not necessarily freezing) conditions for the required time. After the correct amount of time has passed, bring your container out and clean it off. If the shoots that have emerged and are white don’t worry, as they will green up once exposed to the light. Pick a cool spot to start the forcing process. Keep them out of direct sunlight for a few days and turn the container one quarter turn each day so the plants grow straight in the container. Keep the pots watered, but not soaking wet. Once blooming has started, your flowers will last longer if you keep them out of direct sunlight, and put them someplace cool, at night.
Don’t be afraid to experiment, and enjoy your early spring flowers!