Optional flower preservative (or make your own by combining 1 teaspoon sugar | 1 teaspoon household bleach | 2 teaspoons lemon or lime juice | 1 quart lukewarm water).
Instructions
Pick a day that is above freezing and cut the forsythia stems in lengths that will fit in your vase (or about 2 feet or less)
Put the stems in a bucket of warm water. Allow the stems to soak up the warm water for several hours. Change the water in the bucket and mix in some floral preservative.
Place the branches in your container and place in a sunlight spot.
Mist the branches occasionally and if the water turns cloudy change it with fresh water.
Continue with the misting and changing water until the buds begin to bloom. It will take about two -three weeks.
Notes
The best time for force branches in colder climates is mid to late February. If March continues to be cold -- you can force later into the month.