March 18, 2016
To Prune or Not to Prune? – That is the Question!
Not all hydrangeas are created the same; therefore, in order to prune your hydrangea, first you must know exactly what type of hydrangea you have. Each type of hydrangea requires specific care. Improper site location and untimely pruning are the top reasons for a flowering problem.
Generally speaking, if you are having blooming problems, there are a few common factors that all hydrangea gardeners should be aware of. Hydrangeas like rich, moist soil. They need to be watered generously, especially on hot days. Horticulturist, David Jones says, “Lighting is very important to hydrangeas. Hydrangeas won’t bloom in deep, deep shade. And, most hydrangeas prefer morning sun and afternoon shade, with the exception of Panicle Hydrangeas, which can tolerate sun all day.” Also, be careful when fertilizing your hydrangeas; too much nitrogen will cause your hydrangeas to grow plenty of green foliage, but no blooms.
When pruning hydrangeas, David follows two basic rules. The first one is to remove a branch if it is crossing with another branch to allow for better air circulation. The second rule is to remove what he calls the “Three D’s”– Diseased, Dead or Decayed wood.
Below is a guide to assist you in getting the best blooms from your hydrangea by properly pruning.
Bigleaf Hydrangea (Typical cultivars: LA Dreaming, Endless Summer, Forever & Ever, Blue Bird, Zebra, Zorro)
This type of hydrangea is your classic type with ball-shaped blooms that are blue or pink depending on the acidity or alkalinity of your soil. Because this type of hydrangea blooms on last year’s wood, pruning should be kept to a minimum. Once new growth starts to appear in the spring and the parts that are not going to sprout are visible, cut off those dead branches. If you need to narrow your plant, select stems at the bottom of the plant and take them all the way out. Evaluate the Three D’s and prune as needed. Over pruning will result in no flowers.
Panicle Hydrangea (Typical cultivars: Limelight, Vanilla Strawberry, Little Lime, Quick Fire)
The Panicle Hydrangea is unlike most hydrangeas in that it can withstand full day sun. It has creamy white flowers tinged with green, which bloom on new wood. Blooming on new wood means that you can cut the plant back by ¾ and have excellent results. All pruning should be done in the winter or pre-spring.
Oakleaf Hydrangea (Typical cultivars: Snow Queen, Ruby Slippers, Pee Wee)
This hydrangea is known for its oak leaf-shaped leaves. While it can handle full sun, the Oakleaf Hydrangea does best with morning sun and light afternoon shade. This slower growing type of hydrangea blooms on old wood which means pruning lightly only for shape, crossing wood and the Three D’s. Take special care pruning since any living tip you prune means less future flowers. Pruning should be done in the late winter, if at all.
The Climbing Hydrangea can be trained onto walls. Living up to the old gardener’s saying about vines, “First it sleeps, then it creeps, then it leaps,” the Climbing Hydrangea is slow growing for the first two to three years and becomes fast growing once established. Its wide, lacecap flowers may take three to five years to start blooming. Because it blooms on old wood, pruning should be done in the winter and you should be very selective in what you do prune. Limit yourself to pruning the Three D’s and any wayward stems for shape correction.
Hydrangeas are the most popular summer-flowering shrubs at Bucks Country Gardens. Available in shades of white, green, pink or blue, they are a beautiful addition to any landscape. There is an endless number of varieties. So if you don’t see your specific variety mentioned in this article, feel free to stop in and ask one of our experts any questions you may have.
Jessie Tanski | Public Relations and Social Media Coordinator
David Jones | Horticulturist, Arborist, & Customer Service Specialist