Can I force a dormant forsythia branch to bloom by bringing it inside?

Question

I live in Massachusetts, where we have approximately three feet of snow in the yard, and the temperature has been well below freezing nearly every day for the last two months. In an article in yesterday's local newspaper, a horticulturist wrote that even though our forsythias will likely flower later than usual this year, a branch can be forced to bloom now by bringing it inside. Is that true? If so, what would be the proper procedure?

Answer 1

Yes you can.

This actually an old German Advent/Christmas tradition in honour of St. Barbara's Day (Dec. 04) and it's usually done with branches of cherry or apple trees. Forsythia will work fine, too. Branches cut on 12/04 should flower by Christmas.

The basic idea is to take branches that have had "winter" (that is, some frost), bring them inside and "make them think it's spring".

So follow these steps:

• Cut healthy branches from either fruit trees like apple, cherry, plum or pear or spring-flowering shrubs like lilac or forsythia. If your winter has been too mild (e.g. when cutting on 12/04 according to tradition), place them for 12-24 hours in the freezer. This should not be necessary in your case.
• Soak the entire branches over night in cool or slightly lukewarm water. A bathtub works well. Please do not dump frozen branches in warm water!

• Re-cut the stems (splicing and/or gently hammering them is optional) and place in a vase with fresh water. There are two schools of thought on how to proceed now:

  • a) First leave the vase in a cool place until you see the flower buds swell, then move to the warmer living room or similar or
  • b) Place the vase in the living area right away.
• Change the water every few days (and clean the vase now and then). Do not place the branches near a heat source like an oven, cooler temperatures around 15°C/60°F are sufficient (think "spring", not "summer"!). Misting the branches can be beneficial to extend the life of the flowers or in a rather dry environment. Expect the first flowers after ca. 3 weeks, but it may take longer.

Hint: This is actually a really nice project for kids, too, either in December (then include a bit of the christian mythology, see link above) or when you are really sick of winter and desperate for a bit of "spring" in the house.