Forcing Branches of Trees and Shrubs

Gardeners can brighten up the last few weeks of winter by forcing branches of flowering trees and shrubs indoors.  Forsythias, pussywillows, serviceberries, crabapples, magnolias, redbuds, and many fruit trees can be coaxed into early bloom indoors, helping revive the spirits of winter-weary Iowans. 

 

Forcing can be done as soon as the buds begin to swell in late winter.  Forsythia and pussywillow can be forced as early as late February.  It’s best to wait until March for more difficult-to-force ornamentals, such as crabapples, magnolias, and redbuds. 

 

Select branches containing round, plump buds.  (Narrow, pointed buds are usually leaf buds.  Flower buds are generally larger and have a more rounded shape.)  Make clean, slanting cuts 1 to 2 feet from the tips of branches with a sharp hand shears.  Selectively remove branches that won’t harm the appearance or shape of the plant.  If pruning fruit trees in late winter, gather some of the pruned material for forcing indoors.  If possible, collect branches when temperatures are above 32 degrees Fahrenheit.  If the plant material is frozen when collected, submerge the branches in a tub or pail of water for a few hours. 

 

Later, set the branches in a tall container of water and place in a dimly lit, cool (60 to 65 degree Fahrenheit) location.  Spray or mist the branches two or three times a day to prevent the buds from drying out.  Also change the water in the container daily during the forcing period.  Daily changes of water should inhibit the growth of bacteria and fungi which could interfere with the absorption of water by the branches.  When the flower buds begin to open, move the branches into a bright room.  Keep the flowering branches out of direct sunlight and in a cool location to prolong the bloom period. 

 

The time period required to force branches into bloom depends upon the plant species and collection date.  Forsythia and pussywillow generally take only one to three weeks to force.  Apple and crabapple branches may take two to four weeks.  The forcing period for magnolias is three to five weeks.  The closer it is to the plant’s normal outdoor flowering period, the less time it takes to force the cut branches indoors.

Category: 

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on February 13, 2015. The information contained within may not be the most current and accurate depending on when it is accessed.