You wouldn’t know it by looking out my window today, but this past Sunday afternoon it hit 50 degrees. I walked about the garden taking inventory, and just as I had hoped, buds were beginning to swell on spring flowering trees and shrubs. To my delight, the Hamamelis (witch hazel) blossoms were beginning to open. It was a perfect time to cut some branches for forcing indoors.
Forcing is not difficult, but it helps to understand a few basics. Many woody plants (trees and shrubs) set their flowering buds during the previous growing season. They must undergo a dormant period (about 6 weeks) of cold temperatures. A sustained warm moist spell following this dormant period will break dormancy. You need to mimic this warm moist spell to trick your cut branches into thinking it is spring.
1. Walk about your garden in search of subjects, observe, and prune.
You can actually tackle some pruning as you search for stems for forcing. As you select branches, remember to consider the shape you want your tree or shrub to grow. Prune on a mild day, preferably in the afternoon. The day’s warmth will aid the plant in taking up water and sugars from the roots. Branches force more easily if they are less than 1/2 inch in diameter.
One of the easiest plants to break dormancy is Forsythia. Other plants to consider are Willows (Salix), Witch hazel (Hamamelis), Winter hazel (Corylopsis), Quince (Chaenomeles), Viburnum, Dogwood (Cornus), Flowering Cherry (Prunus). I thought I would experiment a bit while I was taking inventory , so I also cut branches of Spirea, Magnolia and Birch (Betula).
2. Hydrate your stems
After you have gathered your array, fill a deep bucket or large pan with warm water, (for really big branches a bathtub works quite well). Submerge your cut branches in the warm water and leave them in a warm spot overnight. You can add a small amount of lemon-lime soda or even Listerine (approx. 1T per quart of water) which will act as a preservative. The next day, under very warm running water, make fresh cuts to your branches. If you have thick branches (1/2? or more), you can split and splay the stems an inch or so for better water absorption. Begin to arrange, or keep these stems in a cool space (45-50 degrees) for a week or so, until you are ready to use them.
3. Create your arrangement
In a fresh vase of water with a bit of preservative, create your arrangement. Some branches will burst open immediately, but others will need more coaxing. Remember your first attempts are about experimenting. Branches which have an interesting shape or color will look fabulous even if they do not force (I’m thinking about the curly willow I used). Every week or two venture outside and select more branches. Take notes on what stems forced well in early February, and which ones might require more time outdoors as winter weather transitions into early spring.