By Brenda Smith
Shoals Extension Master Gardener
Note: This is the first in a series of blog posts from Shoals Master Gardeners, a program of the Alabama Cooperative Extension System that’s the primary outreach organization for the land-grant mission of Alabama A&M & Auburn universities.
One plant that is coveted for its beautiful blooms is the hydrangea. They are often a part of our southern culture with Mopheads (Macrophylla), Oakleaf (Quercifolia), Panicles (Paniculata) and Smooth (Arborescens) leading the way. They all prefer soil rich in organic matter and consistent moisture. Most do best in zones 6 – 9. But then the gardener is tested: Does my hydrangea need sun or shade (how much) and do I prune it?
Bigleaf or mophead hydrangeas are typically those we see with colorful blooms. They prefer morning sun (at least four hours) and bloom on “old growth.” The soil pH affects the color for most in this category. Some blooms are lace cap variety with an airier appearance. The Macrophylla are susceptible to damage from late frosts – or being incorrectly pruned because they have “ugly sticks” showing. Be sure to purchase the right size plant for your space – these plants generally should not be pruned. Look for plants labeled as “rebloomers” so if there is a late frost, there will still be blooms. Examples include Nikko, Endless Summer, Summer Crush, Popstar, Eclipse, Twist & Shout, etc.
The Oakleaf Hydrangea is the Alabama state wildflower & is native to the Southeast. It has massive oak-shaped leaves that show beautiful fall color. They also prefer morning sun and should not be pruned as they bloom on “old wood.” Unlike the rounded blooms of the mophead, Oakleaf blooms are more cone shaped and can be tight or lacy. The Oakleaf has beautiful peeling bark. Examples include Ruby Slippers, Alice, Munchkin, Gatsby Star, etc.
If you don’t have afternoon shade or a green thumb, look for a Panicle hydrangea — or hardy hydrangea. They bloom on “new wood” so late frosts do not harm them and some over-eager pruning won’t destroy your blooms. In fact, they should be cut back about 1/3 in early spring and will produce large cone-shaped blooms. Some of the white/cream blooms are tighter while others are more open. They can change color as they mature but don’t be misled by the tag showing vivid red blooms in fall – our nighttime temperatures are not cool enough for this intense color change to happen. However, new varieties are being developed to help us in the south experience this “spring sizzle.” Examples are Limelight, Little Lime Punch, Bobo, Peegee, Little Quick Fire, Vanilla Strawberry, Pinky Winky, etc.
The Smooth Hydrangeas (Arborescens) bloom on “new growth” and should be pruned by 1/3 to encourage new growth in the spring. They have huge globe-shaped blooms that will show signs of wilting if water is needed. They can tolerate more sun than the mopheads. The flowers tend to be white although there are varieties of light pink colors. Varieties are being developed to reduce the floppy stems sometimes seen after a hard rain. Examples include Annabelle, Invincibelle, Incrediball, FlowerFull, Storm Proof, etc.
Since hydrangeas come in all sizes, you can certainly find the “perfect one” for your yard. Containers are ideal for some of the smaller varieties and those that need extra winter protection. Check out other kinds of hydrangeas including Mountain (Serrata), Cascade hydrangea, and Climbing hydrangeas. There are many new cultivars each year. Always remember to check the tag for hardiness zone, sun/shade needs and size. Select the right plant for the right place!
