Hydrangea is an old-fashioned perennial shrub that will light up the landscape with it's attractive foliage and huge, showy blooms. There are several ways to propagate hydrangea from an existing hydrangea bush, and while propagating them in water may not be the most reliable, it's certainly the easiest. Give it a try, and with good care and a little luck, you'll soon have a hydrangea rooted and ready to plant.
Take a 6-inch stem cutting from the tip of a healthy hydrangea shoot. A shoot lower on the plant, or in the center of the plant, will be more likely to root successfully. In order to make a clean, hygenic cut, use a sharp knife that has been wiped with rubbing alcohol.
Pinch off the leaves on the bottom 3 inches of the stem, and put the stem in a jar of water. Don't allow the leaves to come in contact with the water.
Put the glass on a sunny windowsill, and change the water often. Allowing the water to become murky can cause the cutting to rot.
Watch for roots to appear in three to four weeks. Leave the stem in the water for an additional two to threee weeks to give it time to develop a healthy root system, then plant the cutting in a pot filled with commercial potting mix.
Put the new hydrangea in a sunny spot, and let the top of the soil dry out between waterings. Too much water will rot the hydrangea's fragile new root system.
Keep the hydrangea indoors until late spring, then plant it in well-drained soil where it will get morning sun and afternoon shade. Spread a thick layer of mulch around the base of the plant to keep moisture in, but don't let the mulch touch the trunk of the new hydrangea bush. Keep the soil moist, especially for the year.