Frequently Asked Questions about Hydrangeas
Why did my hydrangea change color?
Oh, this is a fun one! The flower color of some hydrangeas (specifically, the pink and blue varieties) is a direct result of the soil's pH level and the presence of aluminum. In acidic soil (pH below 6.0), the plant can absorb aluminum, which results in beautiful blue flowers. In alkaline soil (pH above 7.0), the aluminum is "locked up" and the flowers will be pink. You can actually manipulate the color! To get more blue, add a soil acidifier like aluminum sulfate or even coffee grounds. For pinks, you can add garden lime to increase the alkalinity. White hydrangeas, though, are unaffected by soil pH, so don't even try to change their color!
Should I cut off the old flowers?
Yes, you can! This process, called deadheading, can tidy up the plant and may encourage the shrub to put more energy into new growth. However, some gardeners like to leave the dried flowers on the plant over the winter, as they can add visual interest and may even offer a little bit of protection to the new buds that have formed underneath. It's a personal choice, really. If you do deadhead, make sure to use clean pruners and cut just above a set of healthy leaves.
What about container hydrangeas?
Growing hydrangeas in pots is totally doable and a great way to show them off! You just need to be extra mindful of their watering needs, as containers dry out much faster than garden beds. Use a good quality potting mix (not garden soil) and a container with excellent drainage. Consider a dwarf variety for a container, and be prepared to water more frequently, sometimes even daily in the heat of summer. You'll also need to provide some winter protection for the pot in colder climates, as the roots are more exposed to the cold than those in the ground.