Gardening 101: French Hydrangeas

Look for French hydrangeas at your local garden center, or order online from Hydrangeas Plus or Wilkerson Mill Gardens. For more information visit americanhydrangeasociety.org.

Despite the variety of colors available, most people associate French hydrangeas with the classic blue hue. Sometimes, the hydrangea you bought as blue changes color and blooms pink the following year.  Your hydrangea is simply responding to the soil pH.  Blue flowers are produced in acid soil (pH 5.5 and lower), and pink flowers are produced in alkaline soil (pH 7 and higher).

You can add aluminum sulfate around your hydrangeas to acidify the soil. Add lime to make your soil more alkaline.  Some selections are less affected by soil pH than others. White-flowering ones, such as ‘Lanarth White’ and ‘Madame Emile Mouillere,’ will stay white.

French hydrangeas can be mopheads or lacecaps. You know the mopheads—big, round clusters of color. Each bloom is a bouquet within itself. Our editor’s pick is the mophead ‘Merritt’s Supreme’ pictured. It grows showy, pinkish red blooms.

Lacecaps, which might not be as familiar, offer flat blooms ringed with very delicate florets. Like mopheads, they have big, green leaves on rounded shrubs 3 to 6 feet high. Our editor’s pick is the lacecap ‘Blue Wave.’ It is a vigorous grower and should be the first lacecap you grow

Light: Plant in mixed sun and shade (won’t bloom in full shade).

Soil: Hydrangeas like moist, fertile, well-drained soil with lots of organic matter, such as peat or chopped leaves. Mulch plants to help keep roots cool and moisture consistent. They’re also great plants for the coast since they can tolerate salty conditions.

Prune: Remove dead growth in spring; trim off faded blooms in summer and fall.

Other pairings: Use such evergreens as camellias and purple loropetalums as backdrops. Ferns and variegated monkey grass work great in the foreground.

Thanks to some hardworking horticulturists, there are lots of selections of remontant (repeat-blooming) French hydrangeas to choose from. Try ‘Blushing Bride,’ ‘Dooley’ (purple bloom pictured), ‘Endless Summer,’ ‘Twist n Shout,’ and ‘Mini Penny’ (pink bloom pictured). They’re especially good if you live in the Upper South or any other area with early fall frosts and cold winters that can cause plants to freeze to the ground.

Tip: Water and feed repeat bloomers consistently to ensure steady blooms.

Create your own pass-along plants by rooting some this summer.

Step 1: Take cuttings in early summer. Use a pair of sharp snips or clippers to take cuttings about 6 inches down from the tip of the stem; then remove the lowest pair of leaves.

Step 2: Use a rooting hormone to get your cuttings started. Wet the ends of cut stems, and dip into a rooting powder, such as Rootone, following the instructions on the label.

Step 3: Stick each cutting in a pot containing moist potting soil, and place the pot in a shady location. Keep soil slightly moist. Cuttings root in six to eight weeks. Add to your yard (or share) in the fall.

• More Tips on Hydrangea Arrangements

• Watch Grumpy’s Hydrangea Tips