Last week I made my annual pilgrimage to the venerable Philadelphia Flower Show, the largest and oldest in the country. Thousands of plants are grown to perfection and forced into bloom. It never fails to get me revved up for spring.
The array of blooming plants at the show got me thinking about the horticultural practice of forcing. Forcing is simply “pushing” a plant into blooming or leafing out earlier than it normally would.
Skilled exhibitors like those in Philadelphia use forcing techniques to create beautiful full-sized gardens with trees, shrubs perennials and even annuals coaxed into bloom weeks or even months before they normally would.
The variety of arrangements is amazing. These skilled designers use everything from dried plant material collected in their own backyards to tropical flowers flown in from around the globe.
Some of the most beautiful arrangements were made using forced branches from spring-flowering trees. These large arrangements gave visitors a taste of what lies ahead a few months from now, when flowering trees like dogwood, cherry, quince and apple will be bursting into bloom.
Fortunately for those of us who want a dose of spring sooner than later, forcing branches of flowering trees or shrubs is not hard.
For best results, choose shrubs or trees that are early bloomers. Branches of forsythia, flowering quince or pussy willow make good candidates, as do those of trees like flowering pear, Witch-hazel or Cornelian Cherry (Cornus mas).
Later-blooming trees like dogwood, crab, cherry and lilac can be forced but take a little practice.
To begin, choose healthy young branches with good bud count. Using a sharp pair of pruners cut branches that area at least 12 inches long (longer is fine) and about the diameter of a pencil.
Immediately place the cut ends in tepid water. Cut more than you need because not all the branches will be successful.
Bring the branches inside and submerge them entirely under room temperature water for several hours. I use the bathtub for this, but a large wash tub or clean plastic trash barrel would work well too.
Soaking the branches softens the outer casing of the buds and prepares them for opening. This process happens in nature over a period of weeks as temperatures rise and spring rain is in abundance. Forcing just hastens the process and tricks the branches into blooming.
After several hours, remove the branches from the water one at a time and remove any side branches protruding from the main stem up about 6 or 8 inches from the cut end. This prevents any branches from rotting under water once they are put in a vase.
Next, make multiple vertical cuts 2 to 3 inches up the stem of each branch. This will help the branch to take up as much water as possible. Submerge the cut branches into a bucket of fresh cool water. Next, wrap the branches loosely in either newspaper or burlap and tie with twine. Place the container in a cool location; 55 to 65 degrees is ideal. Mist the newspaper or burlap with water until it is saturated. Keeping the humidity high around the branches is important. Change the water in the bucket frequently and mist the branches often so they don’t dry out.
Keep the branches out of direct sunlight until they start to show color. Depending on the type of branches and how close to the plant’s blooming you cut them, this could be anywhere from a few days to a few weeks.
Once they begin to show color, place the branches in a vase and move into bright light. Avoid placing the vase in a warm room as this may push the flowers to open too fast and they will not last as long.
Once you see how easy it is to force flowering branches you may end up celebrating spring a few months early every year without having to leave home.