Get The Low-Down On Hydrangea Care
One of the South's most iconic plants is also one of the easiest to grow.
Let’s face it. We might fancy ourselves modern Southerners, but when it comes to our gardens, we dream of a Memaw landscape—one loaded with classic Southern plants like azaleas, camellias, gardenias, and hydrangeas. Most especially hydrangeas.
Before you plant them for the first time, you've got a map to read and a couple of decisions to make.
How to Plant Hydrangeas
First, what plant zone do you live in? Different species thrive in different zones, so you’ll need to find out which ones work best in your area. You can check out the USDA’s plant zone map here.
Next come the aesthetics. Are you looking for a shrub that’s 3 feet tall or 6 feet tall? (You can even plant a hydrangea vine, but that might be more than we want to dig into, no pun intended. ) Should you go with white, blue, pink, red, or purple?
Write this down: There are all kinds of hydrangeas out there, and the more carefully you choose, the happier you and your shrubs will be together.
When in doubt, consult Steve Bender, our resident Grumpy Gardener—“Grumpy” to his loved ones. Grumpy sorted out the hydrangea conundrum back in 2015 with The New Southern Living Garden Book, which we’re about to raid on your behalf.
Hydrangeas fall into two major camps, ‘Mopheads’ or ‘Lacecaps,’ and the flowers look like the names sound. Mopheads have large, round or conical clusters of blooms. The sterile flowers on the outside are so big, showy, and dense that you can’t see the fertile seed-producing flowers on the inside. Lacecaps, on the other hand, display flattened clusters of fertile flowers that have sterile flowers ringing around them.
Write this down: Mophead hydrangea blooms are big and poufy like a mophead. Lacecap hydrangea blooms are delicate and airy like a lace cap.
How to Care for Hydrangeas
How do you care for your Mopheads and Lacecaps? Most hydrangeas are happiest in well-drained, fertilized soil; most like morning sun and afternoon shade; and they need plenty of water or they’ll get seriously droopy in summer’s heat.
Write this down: Hydrangeas like the same thing as the rest of us in warm weather: Afternoon shade, something cold to drink, and plenty of good food.
How to Prune Hydrangeas
When do you prune? That depends, per Grumpy. Generally speaking, hydrangeas don’t need much quality time with the shears. Here are the specifics:
- Hydrangeas that bloom on new growth: Prune in late winter.
- Hydrangeas that bloom on last year’s growth: Prune as this year’s blooms begin to fade.
- Hydrangeas that repeat-bloom: Prune anytime.
Do as I say, not as I do: I prune my hydrangeas when I see more sticks than flowers. So far, it’s working for me, but you should probably listen to the Grumpster.
How to Change a Hydrangea's Color
What about that change-pink-to-blue and vice versa trick? Per Grumpy, among all the hydrangeas featured in the The New Southern Living Garden Book, the color swap works only on three species—H. aspera, H. macrophylla, and H. serrata—and for selections with blue, purple, pink, or red flowers.
Here’s the pink and the blue of it:
- Strongly Acid Soil (pH 5.5 or lower) = Bluest Flowers
- Aklaline Soil (pH 7.1 and higher) = Pink and Red Flowers
- Slightly Acid/Neutral Soil (pH 6.5-7) = Mix of Blue, Pink & Purple Flowers
- To Go Blue: Sprinkle aluminum sulfate or garden sulfur around your plant and water it in.
- To Go Pink and Red: Do the same with lime.
- Sprinkling either around a white hydrangea won't change its color.
Write this down: Per Grumpy, don’t get in a hurry. You might have to repeat applications for a year before you see a transformation.
This too: Plant whatever color you like and if it changes over time, just chalk that up to the thrill of gardening.
WATCH: Essential Southern Plant: Hydrangea
What's not to love about hydrangeas? This Southern classic looks beautiful in your garden, but its showy blooms also make great cut flowers for arrangments.