Kelly Jackson
Christian County Extension Office
Spring Flowers in Winter
Forcing spring-blooming trees and shrubs to flower indoors this winter can be a fun project with kids and a great way to kick the winter-time blues.
Spring-blooming trees and shrubs, like dogwood and forsythia, are the only woody plants capable of being forced. This is because spring-blooming plants set their flower buds in the fall before going dormant. However, plants must experience a period of dormancy before they will bloom. This can vary for each plant but on average 8 weeks of temperatures below 40 degrees F (typically by mid-January or February for our area) will meet this dormancy need. A period of two to three weeks of warm temperatures and moisture will break dormancy and allow plants to bloom. By recreating these conditions indoors, we can effectively duplicate spring and force blooms to appear.
To try forcing some of your plants, prune branches on more mild winter days during the warmest part of the day as the buds will be softer and to ease the transition to indoors. Make sure your branch has flower buds and not just leaf buds. Flower buds are typically round and fat; leaf buds are smaller and pointed. You will want at least a 12-inch-long branch less than ½ diameter with lots of plump flower buds. Follow good pruning practices and don’t leave behind stubs on the trunk. Also limit how many branches you take from one part of the tree as this could impact the natural spring display.
There are differences of opinions on what to do with the branches once you bring them indoors. The commonly agreed points are that everything on the branch that will be submerged should be removed (i.e., buds, twigs, leaves). The branches should also be placed in a container of warm water until the buds start to swell, changing the water every few days to limit bacteria growth. Some recommend cutting another inch off the bottom of the branch while keeping it submerged in water to keep air from entering the stem and blocking water uptake. Others recommend mashing the bottom inch or two with a hammer and then placing in the water. Most recommend a flower preservative. These are available to purchase, or you can make your own. Once the flower buds start to open, then you can transfer the stems to your water-filled vase for display. The vase should be placed in a cooler spot (50 to 70 degrees) and out of direct sunlight for longer lasting flowers. Keep ample water in the vase.
Some plants are easy to force while others may take some time. The closer to spring you take cuttings, the faster they will bloom. Here are few plants you can try and the approximate time it will take for them to flower.
Two Weeks to Force
Bridal Wreath Spirea: small white flowers in sprays
Cornelian Dogwood: dainty, yellow flowers in clusters
Forsythia: many yellow flowers
Serviceberry: dainty, white flowers
Witchhazel: yellow, strap-shaped petals
Three Weeks to Force
Flowering Almond: delicate pink flowers
Wisteria: blue-violet or white flower clusters
Cherry: white or pink flowers in clusters
Four Weeks or Longer
Beauty Bush: small clusters of pink flowers
Flowering Quince: long lasting red or orange flowers
Lilac: fragrant lilac, blue, purple or white flowers in large clusters
Redtwig Dogwood: white flowers with red stems
Flowering Dogwood: large white long-lasting flowers
If you have a branch that doesn’t flower, you may have cut it too early. The closer to the plant’s natural bloom time when it is brought indoors, the faster it will bloom. Also, plants that were pruned after bud set last year may not have many flower buds and therefore may not bloom.
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