The landscape may lack color in the late winter months, but with the right planning and a little effort, you can create an early spring indoors or make a lovely gift by forcing your own succession of hardy bulbs.
Bulbs are perennial plants that overwinter as fleshy, underground structures. These types of plant structures collect carbohydrates from the leaves during photosynthesis and are stored as nutrients for future growth.
There are many plant species that use this specialized energy store. Loosely grouped with bulbs are bulbs such as crocus and gladioli, tubers such as caladia and Irish potatoes, root bulbs such as dahlias and sweet potatoes, and rhizomes such as irises and pitchers.
True onions are compressed, subterranean stems (baseplate) with a modified flower bud surrounded by modified fleshy leaves called scales. Two of the most well-known examples of true onions are onions and garlic. When thinking of flower bulbs, the most well-known are tulips, daffodils, hyacinths, lilies, Dutch irises, paper whites and amaryllis.
Bulbs can be planted from mid-September to December, depending on the desired flowering date and storage period. Generally, spring bloomers require eight to 12 weeks of chilling at 30 to 35 degrees F. Mid spring bloomers require 12 to 14 weeks of chilling and late spring bloomers require an average of 16 weeks.
A refrigerator is the perfect place to chill flower bulbs as it keeps the required temperatures constant for the required period of time. Vegetable drawers are often used.
It’s fun to get spring-blooming bulbs blooming indoors. We can encourage many types of bulbs to flower early by providing the right environmental conditions and cool temperatures.
Enforce light bulbs by placing them in dark, cool places. They can be bare or planted in soil, planted in containers and placed in refrigerators. Some can be refrigerated and then placed in bulb vases which will support growth and develop roots and shoots.
Some of the most common hardy bulbs used for forcing are crocuses, daffodils, hyacinths and tulips. Some others are dwarf iris (Iris reticulata), Dutch iris (Iris x hollandica), grape hyacinth (Muscari spp.), glory of the snow (Chionodoxa luciliae), snowdrop (Galanthus nivalis), and summer snowflake (Leucojum aestivum).
Cooling is the most important part of successful bulb cultivation. All bulbs except amaryllis need a cold period before flowering. Being native to the tropics, Amaryllis bulbs do not require a chilling period.
Amaryllis takes six to eight weeks to flower after planting and paper white takes three to five weeks after planting. If you want to give both as Christmas gifts, start now!
Once the chilling period arrives, it takes about two to three weeks for the stem to elongate and the flowers to open.
Crocus and grape hyacinth take eight to 15 weeks to chill. Daffodils, hyacinths and irises take 13 to 15 weeks. Tulips take 10 to 16 weeks and snowdrops 15 weeks.
In general, bulbs for flowering in January should be chilled in September. For blooms in February, cool in October and so on.
At the end of the cool down period, check the pots for roots sticking out of the drain holes. This signals that they are ready. At this point, remove the bulbs from cold storage and place them in a cool room, 60 to 65 F. Higher temperatures will speed up the process of growth and flowering. Lower temperatures encourage compact growth.
Pot deep enough so that there is a few inches of soil under the bulbs and it covers up to the bulb necks. They can pack in as many lightbulbs as the media will allow and they’re pushing. If you want to grow after cut flowers, force them into apartments. Make sure all onions need the same chilling time.
After planting, be sure to keep the soil moist, not wet. You can “wake up” the bulbs by giving them a few weeks of warmer temperatures and indirect sunlight. Once the bulbs are tall and a few inches tall, give them more sun and a warmer spot. This will cause the onions to bloom.
Pro Tips: You can prolong flowering by placing pots in indirect light and keeping them in a cool place or the fridge at night. Also, to keep the stems straight, rotate the pots regularly. You can also buy already chilled onions.