One of the questions we get the most in spring is “How do I prune my hydrangea?”. It seems like we all have one somewhere in the yard adding much needed summer flowers and winter interest. There are a couple of questions to ask yourself before you pick up the pruners.
Does it need pruning?
If you like the size and shape it is right now, let it be. Spring is a good season to see how the stems are growing and the overall architecture of the plant. In general, we suggest a light deadheading of the dried flower heads to clean up the shrub for spring.
Look for crossing and rubbing branches or any that are damaged. Also check the direction the stems are growing. You want the stems to be growing outwards, not toward the center of the shrub where they have the potential to rub across others and cause wounds. Prune out inward facing twigs. You may need to wait until the snow melts a bit more to see the extent of any damage. The rabbits and deer have been very hungry this year and you may see evidence of chewing. Rabbits will nibble or remove branches with a clean, sharp cut. Deer tend to leave ragged ends.
What type of hydrangea is it?
We’ll commonly see four types of hydrangea in the Chicago area:
Hydrangea arborescens – These shade lovers bloom in June with huge, white, dramatic blossoms. Common cultivars are ‘Annabelle’, ‘Incrediball’, or ‘Invincibelle Spirit’, which is pink. You have a couple of choices with these hydrangeas. You can lightly deadhead the dried flowers and leave the stems for a larger, sturdier plant. You may also cut the canes back to between 6” to 12” to maintain a shorter shrub.
Hydrangea macrophylla – This hydrangea is short and blooms most of the summer into fall. The blossoms are pink in our soils or change to blue with an acid fertilizer. Common cultivars are ‘Endless Summer’, ‘Twist ‘n’ Shout’, or ‘Let’s Dance Moonlight’. With this type, be patient. Wait until the buds start to open before you prune it. This allows you to see which twigs are still alive and which didn’t make it through the winter. This type will bloom on old and new wood, but can bloom better on older stems.
Hydrangea paniculata – This type has increased in popularity due to its sun tolerance and color changing flowers that go from white to pink as the summer progresses. Some common large cultivars are ‘Limelight’, ‘Pinky Winky’ or ‘Quickfire’ and many newer ones are smaller like ‘Little Lime’, ‘Mystical Flame’ or ‘Bobo’. Panicle hydrangeas bloom on new growth, so you can either give them a light deadheading if you enjoy their size or cut them back by one third if the shrub is too large.
Hydrangea quercifolia – Oakleaf hydrangea is a little different. We love it for its big, coarse leaves and gorgeous fall color. Some common cultivars are ‘Alice’, ‘PeeWee’, and ‘Snow Queen’. Because this hydrangea grows slowly and blooms on old stems, we recommend only a light deadheading to take the dried flowers off. Watch for rabbit damage. This hydrangea can be a particular favorite of theirs.
Posted on 3/5/2014 at 7:15:00 PM