Hydrangeas are fairly easy to propagate. It usually works best by using a cutting from a stem that didn’t have a flower on it.
Take a cutting from a branch about 5-6 inches in length
Remove the lower leaves
Cut the larger leaves down to about one-half of their original size.
Dip the cuttings into rooting hormone.
Prepare rooting medium by placing into container and add water. I prefer to use perlite but some folks like to use vermiculite or sand.
Some like to cover the cutting with plastic, a 2 liter soda bottle works well
Place under grow lights. I use shop lights with one warm white and one cool white light bulb. Make sure they get at least 12 hours of light per day. DO NOT PLACE IN DIRECT SUNLIGHT.
Keep the medium damp but not soaking wet.
Roots will usually develop with 2-3 weeks.
When roots are developed pot in a regular potting soil and keep under lights until ready to move outside. Before moving harden it off like you would any seedlings.
Those you in USDA Zones 6 and colder who grow lacecaps and mophead hydrangeas should provide some sort of protection to ensure the developing buds won’t freeze. I have devised a system that has worked fairly well for the past several winters.
I use garden twine to tie the branches together and make the plant a small as I can, being careful to not damage developing buds at the tips of the branches. I then make a cage from chicken wire by driving wooden stakes into the ground around the perimeter of the plant. I attach the chicken wire to the stakes. I then fill the cage with shredded leaves. If you don’t have a chipper you can shred the leaves by running them over several times with a lawn mower. Straw, pine needles or similar mulching material may be used. Leaves the plant covered until spring when danger of freezing has passed. This method has worked very well for me.
If this sounds like too much trouble you might want to try and grow hydrangeas in pots. These may be moved into a garage or cellar during the winter to protect them. I do this with roses and it also works quite well. Give them a good watering once a month.
Preserving the Blooms
Hydrangea blooms are very easy to dry and preserve. The secret to getting blooms to look right is to cut them at the correct time: wait until they are past the peak of their color before cutting them.
After cutting, strip off the leaves and place into a vase without water and leave to dry. As they begin to dry they will pick up very interesting hues of color.
This arrangement was made from white flowers.
This has been drying for about three weeks and is starting to show hues
of pink although not showing up well in the photo.
You can also use Rit clothes dye to color your blooms to whatever shade of pink or blue that you desire.