Winter is tough on everyone. Dark, gloomy, cold days just make people feel less than upbeat, said Greg Stack, University of Illinois Extension horticulturist.
“We can’t wait for spring to come and often wish we could help it arrive a little sooner,” said Stack. “Well, there is a way to push the season a bit and at least bring a little of spring indoors to brighten our mood. Try tricking some spring flowering trees and shrubs into flower early indoors, a process known as forcing.”
Trees and shrubs that flower in the spring form their flower buds the previous summer and fall. So they are ready to burst into bloom when the time is right. These plants are “programmed” to start flowering after they have received the right amount of cold. At least eight weeks of temperatures below 40 degrees are needed in order for these branches to start flowering. Once these temperature requirements are met and the right forcing conditions indoors are provided, you can enjoy spring just a bit earlier.
To make sure the branches have received enough cold, don’t start cutting branches until at least after January 15 or so. Keeping track of daily temperatures helps to pinpoint this more accurately.
“After the prescribed “chill hours” you can go out to the garden and carefully prune out branches for display indoors,” he said. “This pruning can be part of the normal winter pruning, saving the branches for indoor use and not the compost pile.”
Stack recommended selecting branches with a large number of flower buds.
“Trees and shrubs produce both flower and leaf buds and sometimes they are one in the same,” he said. “Flower buds tend to be larger, rounder and fatter. If you still can’t tell for sure cut open a few buds. The flower buds will actually have flower parts visible inside.
“Make clean cuts and immediately place the branches into water. Also, making a cross or star shaped cuts on the ends of the branches allows for water to be absorbed more quickly. Don’t smash the ends of the stems as was once suggested to help with water uptake as this could have the opposite effects if crushed too hard.”
To help the flowers emerge easier submerge the branches in a bathtub full of water and leave them there overnight. This allows the stems to quickly absorb water and to soften the scales that cover the buds.
Remove the stems from the bathtub and place in a bucket of water in a cool area (60 degrees).
“Warmer temperatures cause the branches to develop too fast,” he said. “Also keeping the branches moist by misting improves flowering.
“Once flower buds start to show color they can be used in arrangements. Keeping the stems out of direct sunlight and moving the arrangement to a cool area at night (40-50 degrees) will extend the life of the arrangement.”
What you cut depends on what you have in the garden and can get locally. Don’t be afraid to experiment with a variety of branches. To start you off, here are a few suggestions and some general time information regarding how long it will take to force branches.
In January look at using Cornelian Cherry with yellow flowers (two weeks to force), Forsythia with yellow flowers (one-to-three weeks to force), Witch Hazel with yellow flowers (one week to force), and Willow with its attractive catkins (two weeks to force).
February offers the chance to bring in Red Maple with red flowers (two weeks to force), Birch with long catkins (two-to-four weeks to force), Cherries with pink flowers (two-to-four weeks for force), and Pussy Willows with furry white flowers (one-to-two weeks to force).
In March, consider Hawthorns with white or pink flowers (four-to-five weeks to force), Apples and Crabapples with white, pink or red flowers (two-to-four weeks to force), Lilacs with purple or white flowers (four-to-five weeks to force) and Spirea with white flowers (four weeks to force).
“By cutting various branches at various times, you can have a succession of bloom indoors and brighten up the dark winter days with an early taste of spring,” Stack said.