Forcing Bulbs for Early Spring Blossoms Indoors
by Henry Homeyer
CORNISH FLAT, N.H. – I love tulips. Fortunately, our dog Rowan keeps the deer away, so I can grow them in our garden. But if you have a deer problem and can’t grow tulips (deer think you’ve planted treats for them) I have a solution. Plant some in pots now so they will bloom for you indoors in March or April.
Almost any spring blooming bulb can be “forced” to bloom indoors, but tulips take the longest: four months. If you were to pot them up in early November, they won’t be ready to start growing leaves and buds until March. But let’s back up a bit and see what they need to thrive and bloom.
First, they need a cool or cold place to rest for four months of dormancy. I am lucky: I have a cold basement that I keep just above freezing, which is ideal. Anything over 50 degrees will encourage them to send up green shoots too early. If they do that, they probably won’t bloom.
A garage attached to the house might be suitable for forcing bulbs. Or maybe you can put them in an unheated mudroom, or spare fridge. If the growing medium freezes it won’t kill the bulbs, but they won’t progress towards the hoped-for bloom time. They need to be growing roots and getting ready to bloom.
You need a suitable container for forcing bulbs. I use an Italian-made red clay container that is 16 inches long, five inches wide, and five inches deep. It is handsome, and will look good on my windowsill when I bring it up from the cold basement to blossom. You can, of course, use a plastic pot or a handsome ceramic pot. I have even used my window box for a bigger splash of color. But anything you use should have a drainage hole and something to catch the water that may leak out of it.
Next, you need a good growing medium. You can buy potting soil, or you can reuse potting soil from last summer’s annuals that were in pots on the deck or steps. A robust annual grows lots of roots which you need to separate from the soil by shaking or banging the soil loose. The soil can then be used, but you should mix it with fresh potting soil, too.
Fill the container you plan to use about half way with the growing medium. If the soil mix is dry, moisten it well before placing the bulbs in the pot. Then push the bulbs into the soil mix, cover the bulbs with more mix and pat it down firmly. You can place them closer together in the pot than you would if planting them outside in the soil. In fact, I plant some bulbs shoulder to shoulder.
You will need to check on the pots once a month to be sure the potting mix has not dried out. If it has, water lightly, but never get the growing medium soggy. But if it is too dry, nothing will happen, either.
Rodents are a problem outdoors: they love to eat tulips bulbs. But if you live in an old house you may also have mice or squirrels in your basement that will eat the bulbs. So I cover each pot with hardware cloth (a wire mesh) or a small piece of board. They won’t eat daffodil bulbs, but I have had rodents dig them up and throw them on the floor in disgust!
When selecting bulbs for forcing, always choose early or mid-season bloomers. I want early blossoms while snow is still on the ground. This is true whether selecting tulip varieties or daffodils. Daffodils generally only need 3 months of dormancy. Crocus and other small bulbs only need two months of cold storage.
My favorite daffodils for forcing is the Tete-a-Tete. These little gems are short and early, and produce lots of flower – two or three flowers per stem. This year I potted up a dozen four-inch pots with three bulbs each. These should be ready to come up into the warmth of the house in about 10 weeks, and ready to gift to friends a couple of weeks later while in bud. There is nothing like a blooming daffodil to pick up a person’s spirits in late winter.
Another blooming treat is the paperwhite. This is a type of daffodil that comes ready to grow. Most people like to set them in a bowl filled part way with stones and add water until it just “kisses” their bottoms. Put on a sunny windowsill, these bulbs will blossom in four to six weeks. Just keep on adding water as it evaporates or is sucked up by the paperwhites.
Paperwhites in bowls of pebbles sometimes get too tall and tip over. Some people add just a soupcon of gin to the water when they start to grow, stunting their growth. Me? I just try to rearrange the stones to prevent tipping. Another way to do it is to grow them in potting soil. But you should not bury the paperwhite bulbs if you do that. Leave half the bulb above the soil line.
A nice project for your garden club would be to pot up some Tete-a-Tete or other bulbs now for later use as gifts to the ill or elderly or anyone who needs them. I know one club that is planning on doing so this year.
[Reach Henry at PO Box 364, Cornish Flat, NH 03746. Include a SASE if you wish a response, or e-mail him at email@example.com. He is a life-long organic gardener and the author of four gardening books.]