A string of sunny days the first week in February had me itching to start working in my gardens. But with only two days with temperatures above freezing and everything still covered in snow, there was little gardening work to be done. I sat on the back porch with my chin in my hand, pondering what I could do to relieve my gardening itch. Then it hit me – though it was still winter outside and spring seemed far away, I could have it come early inside the house.
The pussy-willow in the ravine already had nice, big fat buds – perfect for bringing indoors to force. Pussy-willows (or any Salix species) and forsythia are natural choices for forcing; they will bloom indoors so easily it’s nearly foolproof. The only effort involved is cutting branches after they’ve gone through a sufficient period of dormancy – generally anytime after January is acceptable – and putting them in a vase of water. They’ll not only bloom, but often grow roots as well. With a little more effort though, the branches of nearly any dormant deciduous tree or shrub can be forced indoors.
Species such as magnolia, flowering quince, American spice bush, flowering dogwood, redbud, crabapple, vernal witch hazel, and lilac are just a handful of flowering trees and shrubs that make good candidates for early indoor blooming. But don’t discount non-flowering species either. Birch and willow provide catkins, and their slender branches make a graceful arrangement. Shrubs with variegated leaves have interest, as do those with dark leaves such as sand cherry or purple-leafed plum. Even those that just leaf out a bright green will brighten any room during the late days of winter.
I’ve been tempted to force branches from my fothergilla; I like the fluffy white, early flowers that Keith calls “bunny tails.” But the shrub is slow growing, and cutting branches to force would have ruined its structure aesthetically. It’s important when cutting branches for forcing not to go hog wild. Cuttings suitable for forcing should be at least a foot long, and consideration should be taken if removal of such branches would disfigure the tree or shrub’s overall appearance.
When making your selection, choose branches with well-developed plump buds. The plumper the bud, the better chance of success you’ll have in forcing it to bloom. Plants closer to their normal bloom or leafing out period outdoors will be quicker and easier to force indoors. The earliest flowering shrubs, such as forsythia, American spice bush, and quince, will generally only take one to three weeks to bloom. Later blooming species should be forced closer to their natural bloom – if brought indoors too early, the buds may dry out and wither before having a chance to open.
The trick to successful forcing is providing constant, sufficient moisture and humidity. If the buds become dry, you’ll end up with nothing but a vase full of dead branches. Your inside environment should mimic that of early spring outdoors. Keeping your cuttings out of direct sunlight and away from heating vents will minimize the chance that they become desiccated. Temperatures ranging from the low to mid-sixties are best.
There are different methods for forcing branches. The simplest method is to just put them in a vase of water – this is recommended for only the most easily forced species such as forsythia and willows. Other methods are more complex and involve completely submerging the branches in water for 24 hours, mashing the stems with a hammer, then wrapping the length of the branch in plastic wrap for another 24 hours to produce humidity before placing the stems in water. That may seem like a lot of effort to go through to have blooms just a few weeks earlier than nature would normally produce them; it seems so to me anyway.
But there is an easier method that works well on most species. Once you've chosen your branches and placed them in a vase, just make sure to change the water every two or three days, making a fresh cut on the bottom of the stems as you do so. Always use well-maintained pruners or a sharp knife to get a clean cut – those made with dull blades can inhibit the branch’s ability to take up water. Keeping the buds moist with daily misting helps to prevent drying. The forcing process can take from one to six weeks depending on the species and how close it is to its natural bloom period.
The pussy-willows opened in a little under two weeks. I added some yellow-twig dogwood branches, boxwood, and variegated euonymus to the bouquet for color-contrast and interest. It’s not the most flowery of displays; the flowers of viburnum, chokeberry, and lilac branches will come later. But with a fresh layer of new snow outside, it’s nice to see a bit of springtime from my gardens inside.
I noticed this morning that the yellow-twig dogwood branches have started to break bud! It’s a pleasant surprise – though I brought them in at the same time as the pussy-willows, I really didn’t expect it to bloom, thinking it was it too early. The open buds reveal two tiny leaves on either side of a lime-green composite flower. The flowers will change to creamy white about the same time the pussy-willow catkins turn fuzzy yellow with pollen. Maybe in the meantime, I’ll start forcing forsythia to add in the vase too, for a whole new look. Experimenting is half the fun.