Now is the perfect time to prune woody plants if they bloom in summer. Some examples are burning bush, hydrangeas, clethra, barberry, St. John’s wort, and weigela. Wait to prune your fragrant viburnums, lilacs, and anything that blooms before Memorial Day until just after they flower. These plants already have flower buds ready to go for spring.
Only prune if necessary to control the size of the plant or to remove dead, crossing or damaged twigs. Opening up the canopy of a tree or the structure of shrubs will allow greater air circulation and reduce fungal disease. Pruning now before leaves appear allows you to clearly see the structure of the plant. Since it’s been so warm and trees are leafing out fast, it’s probably a little too late to prune your oaks and elms. Oaks and elms should only be pruned while insects are still dormant to prevent the spread of Dutch Elm Disease and oak wilt. You should also prune birch and maples early because pruning cuts may weep excessively once sap begins to flow. It won’t hurt the tree, but it can be unsightly. Stop in April 2, Opening Day in Aurora at 1:40pm for our Pruning Do’s and Don’ts talk. We’ll show you what to do and not do for pruning success and long lasting, beautiful trees and shrubs.
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. 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:
Annabelle Hydrangea (Hydrangea arborescens)
These shade lovers bloom in June with huge, white, dramatic blossoms. Common cultivars are ‘Annabelle’, ‘Incrediball’, or ‘Bella Anna’, 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.
Endless Summer Hydrangea (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 ‘Bloomstruck’. 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.
Limelight Hydrangea (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. There are a multitude of varieties to choose from large to small to any size in between. Some common large cultivars are ‘Limelight’, ‘Pinky Winky’ or ‘Quickfire’ and many newer ones are smaller like ‘Little Lime’, ‘Mystical Flame’, Little Quickfire’ 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.
Oakleaf Hydrangea (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’, ‘Munchkin’ 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 3/17/2016 at 5:49:00 AM