Forcing Branches of Flowering Trees and Shrubs

(The following article appears in The New England Gardener’s Year by Reeser Manley and Marjorie Peronto (Cadent Publishing), now available at your local bookseller.  Reeser will be signing books and answering garden questions at the Portland Flower Show on Saturday, March 9, 2013.  Stop by and say hello!)

By early March, gardeners are aching to be in the garden.  Why not get a head start on pruning trees and shrubs and, at the same time, bring a touch of early spring into the house?  Branches of many woody plants can be forced into early flower or leaf in late winter, providing a glimpse of the season ahead.

Trees and shrubs that lend themselves to forcing include:

Forsythia (Forsythia sp.)   yellow flowers

Cornelian Cherry Dogwood (Cornus mas)   yellow flowers

Poplar (Populus sp.)   long lasting, drooping catkins

Willow (Salix sp.), including Pussy Willow   catkins

Red Maple (Acer rubrum)   pink to red flowers followed by leaves

Swamp Alder (Alnus rugosa)   yellow male catkins

Birch (Betula sp.)   long lasting catkins

Flowering Quince (Chaenomeles sp.)   red to orange flowers

Cherries (Prunus sp.)   white to pink flowers

Rhododendrons and Azaleas (Rhododendron sp.)   many colors

Hawthorns (Crataegus sp.)   white, pink, or red flowers

Apples and Crabapples (Malus sp.)   white, pink, or red flowers

Oaks (Quercus sp.)   catkins

Lilacs (Syringa sp.)   many colors

Spirea (Spiraea sp.)   white flowers

Serviceberries (Amelanchier sp.)   white flowers

Horse Chestnut (Aesculus hippocastanum)   umbrella-shaped leaves, pyramids of flowers

Beech (Fagus americana)   flowers in long drooping spikes

Tamarack (Larix laricina)   green needle-like leaves

Japanese Andromeda (Pieris japonica)   evergreen foliage, clusters of small while flowers

Beauty Bush (Kolkwitzia amabilis)   pink flowers

Deutzia (Deutzia gracilis)   white flowers

Mockorange (Philadelphus coronarius)   white fragrant blooms

Spicebush (Lindera benzoin)   fragrant pinkish-white flowers

Take cuttings on a mild afternoon when the temperature is above freezing and the stems are soft and pliable.  This will ease the transition from the cold outdoors to the warm indoors.  As you prune to shape the tree or shrub, removing competing, crowding, and crossing branches, set aside cuttings of younger shoots at least 12 inches long with abundant flower buds, distinguished from leaf buds by their larger size and rounder shape.  If in doubt, cut open a few buds to look for leaf or flower parts inside.

Select only branches that are well budded.  Also, remember that many fruit trees, such as apples, crabapples, and cherries, bear flowers on short shoots called spurs.

Once inside with your collection of cuttings, fill both the sink and a bucket with warm (100 ºF) water.  Many experts suggest adding a floral preservative  to the water to promote hydration and retard bacterial growth.  Recipes for home-made preservatives are given below.

Holding the stems underwater in the sink, cut them at a sharp angle an inch or two above the original cut.  Split the stem in half on larger branches (more than a half-inch in diameter) with an inch-long lengthwise cut that exposes more of the water-conducting tissue to the forcing solution.  Making these stem cuts underwater prevents entry of oxygen that could block uptake of water.

Immediately place the stems in the bucket of warm water and set it aside in a cool place where the temperature stays between 60 and 65 ºF, then arrange the stems for display as the buds begin to show color.  Alternatively, you can immediately create an arrangement and place it on display in a cool location for all to watch as the buds slowly swell and open.  Remember, high temperatures speed up bud development, but reduce the size, color, and keeping quality of the blooms.  Keep the arrangement away from direct sunlight and away from any direct heat source, such as a heating vents or the wood stove, that would dry out the buds.  A cool location with bright indirect light is best.

Change the water and add new preservative each week.  If the surrounding air is dry (often the case in rooms with a wood stove), mist the arrangement with water several times a day to keep the bud scales moist until flowers or leaves emerge.  Once the buds open, a process that can take two to three weeks, the blooms should stay fresh for at least a week.  Branches forced for their foliage will last even longer.

For a succession of forced blooms and foliage throughout the month of March, cut a variety of branches at various times.  Treat yourself to an early spring!

Homemade Floral Preservatives

The staminate (male) catkins on alder branches can be forced into bloom in March, often accompanied by last year’s female catkins.

You can purchase floral preservatives or make your own.  Here are a couple of recipes.

2 cups lemon-lime carbonated beverage
2 cups water
1/2 teaspoon household chlorine bleach

2 tablespoons fresh lemon juice or white vinegar
1 tablespoon sugar
1/2 teaspoon household chlorine bleach
mix with 1 quart water

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About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)