Bulbs that Bloom Indoors or Out

Blooming bulbs, especially amaryllis and paperwhites are part of the holiday season. Watching the bulbs produce their blooms adds interest and enjoyment their decorative role. Crocus, daffodils, tulips and hyacinths, too, often come to our homes. They arrive in gift baskets full with blooming flowers that have been forced to bloom indoors for the holidays.

All of these bulbs fall into one of two categories, those that need a chilling period before they bloom and those that donít. Amaryllis, daffodils and paperwhites are native to tropical and subtropical climates. They do not need pre-chilling. However, hyacinths, crocus and tulips need a chilling period to bloom outside their native climate and natural schedule. A proper chill releases a hormone that signals the bulbs to develop their root system in preparation for spring bloomsóindoors or out.

If you want the this yearís crocus, hyacinth and tulip bulbs in your garden to bloom outdoors next year, you will need to dig them up after their foliage has yellowed and died back, brush off the soil and store the bulbs. Then pre-chill the bulbs in your refrigerator for 12 ñ 20 weeks and plant them again next fall.

The labor involved in digging, storing, chilling and replanting these bulbs is usually not worth the effort. It is easier to grow the bulbs like annuals. Leave them in the ground. Many wonít come up again. The few that bloom next year likely will be stunted.

Pre-chilled bulbs offer home gardeners the option to force the bulbsí blooms and enjoy them during the dreary winter doldrums.

Forcing a bulb takes a lot out of it. Donít try to force a bulb for a second time. Always use a new bulb.

When choosing bulbs know that early flowering varieties typically need fewer chilling hours than those that bloom later in the season. Tulips that have not been pre-cooled need 14 ñ 20 weeks in your refrigerator; a hyacinth requires 10 ñ 14 weeks.

A few mail order bulb catalogs still have pre-cooled bulbs available. I found some this week at BrentandBeckysbulbs.com. However, you may need to call few sellers to ask about availability.

You can force chilled bulbs in a pot of soil or a bulb vase filled with water. Azalea pots are the best pots to use when forcing bulbs in soil. They are æ the height of a normal pot of like diameter. Potting soil must be well draining yet hold enough water to stay moist.

Plant bulbs broad side down, pointed side up. Place them close together without letting them touch. If you encounter a bulb with no discernable top or bottom plant it on its side. The roots will grow downward and the leaves will grow toward the light. Plant tulips with flat side facing the side of the pot. That encourages the first leaves to form a green border around the edge of the pot.

Whether in soil or water pre-cooled bulbs need to start out in a cool dark place about 45 ñ 52F. When the root system has developedóroots will be about two inches long and extend to bottom of a water vase or peek out the drain hole of a pot of soilómove your bulbs inside to a cool spot 60 ñ 70 F. Shoots will be two to three inches tall. Protect the bulb from direct sun until the pale foliage has greened up. You can then move the bulb to bright light. Maintain moisture in soil or water level in the vase.

A gradual move to warm temperatures yields longer-lasting blooms. Bulbs should bloom about two to three weeks after they move to bright light. Warmth speeds up the process, but flowers will not last as long.

If you want your bulbs to flower by a certain date, and you chill them yourself, itís a months- long process that begins in the fall and requires careful calculations. If you havenít forced bulbs previously do it for your own enjoyment rather than a deadline the first few times.

For more information on forcing bulbs google Clemson hgic1155 and Clemson hgic1156.

This story was originally published December 12, 2015 at 12:00 PM with the headline "Bulbs that Bloom Indoors or Out."