Hydrangeas are beautiful bushes with big, bold blooms in shades of pink, blue and purple. Hydrangeas are an unusual plant, because the colors can actually be altered and controlled by the addition of acid or lime to the soil. If you have access to a healthy hydrangea, it’s easy to grow new bush from stem cuttings. Plan to take cuttings in spring or early autumn.
Cut a piece of green stem from a healthy hydrangea bush. Make the cut with about 2 inches of stem below a set of leaves. If you aren't ready to use the cuttings, wrap the stems loosely in damp paper towels and put them in an unsealed plastic bag. Put them in the refrigerator and store them for up to two days.
Make a planting medium by mixing one part potting soil or peat moss with one part perlite, vermiculite or sand. Fill the pots with the mixture.
Set the pots in a pan or basin, and add water until it reaches nearly to the top of the pots. Leave the pots in the water for an hour, misting the top of the soil with a spray bottle every 10 to 15 minutes.
Remove the stem cuttings from the refrigerator. Using a clean pair of scissors, cut off the top halves of the leaves. This will make the cutting absorb water more efficiently.
Dip the ends of the hydrangea cuttings into rooting hormone, and then stick the stems into the pots, up to the bottom edge of the leaves. Mist the pots until the soil is soaked.
Put the pots in a protected corner of your yard or garden, out of wind and direct sun. Spray the cuttings lightly three times a day for the first week, or as often as needed to ensure that the soil doesn’t dry out. Time the waterings so that the soil is always damp, but not soaked. Don’t mist the cuttings in the evening, which can invite mildew and disease.
Check the hydrangea cuttings in three weeks to see if they’ve rooted. Look on the bottom of the pot for tiny white roots, or tug gently on the cutting. If you feel resistance, the cutting has rooted.
Choose a planting site where the hydrangea will be protected from strong winds and from hot afternoon sun. Work the soil to a depth of 8 inches with a shovel or hoe, and mix a generous shovelful of compost or manure into the soil. Add a dose of time-release fertilizer, according to the manufacturer’s directions.
Water the hydrangea deeply once every week, and feed them with time-release fertilizer once during the spring and once during the summer.