We received several big leaf hydrangeas as memorial gifts when my Dad died in 2009. When I first planted them, they were in full sun all day and didn’t like it much. Here are some sowing and growing tips. . .
Sow/Plant:
1) While I have never noticed any seed companies selling hydrangea seeds, you can collect seeds in the fall from an existing hydrangea and sow them in the spring. -OR- You can buy a plant. 2) Sow or plant your hydrangea in a location that gets morning sun.
Grow:
3) For nice blooms, make sure the hydrangeas get enough water and not too much nitrogen. Since hydrangea are acid loving plants, I give my plants, Holly-tone in the spring and fall according to the package instructions. If your blooms are blue and you want pink, then apply some Garden Lime according to the package instructions. I purchase these products from Espoma. 4) Unfortunately, my plants did not come with plant tags so I wasn’t sure what variety of big leaf hydrangeas they were so I wasn’t sure when to prune them. Since some varieties bloom on new growth and some on old growth, pruning at the right time is critical for flower production.  If your hydrangea blooms on new growth, you can leave the woody stem up through the winter and cut them back in the Spring after the plant starts to show the new growth. If your hydrangea blooms on old woody stems like my plant does, then prune the stem after it is done blooming. 5) You can divide hydrangea with a shovel if your plant is getting too big or if you would like more hydrangea to plant.
If you missed my post on Wave Petunias, you still have time!