What Is a French Hydrangea?

Plant Form

• The French hydrangea grows as a bushy shrub. The plant produces woody stems with large oval leaves. The foliage typically has a deep green color in the spring and summer, with some varieties producing vibrant fall colors. The height and spread of French hydrangea varies depending on the type. The lower growing varieties reach 4 feet tall while larger types grow up to 12 feet. The plant's spread is typically close to its height, but pruning can result in a wider or narrower plant form.

Flowering

• The true beauty of a French hydrangea is in the blossoms, which occur primarily in the late spring and early summer. The plant produces clusters of small flowers in shades of pink or blue. Flower color depends on the soil pH, or acidity, in the growing site. Acidic soil results in blue flowers, while alkaline soils produce pink blossoms. The shape of the flower clusters depends on the variety. Hortensia types produce orb-shaped, tightly packed clusters while lacecap types have flat, loose clusters of flowers.

Cultivars

• Hortensia French hydrangea are the lower-growing varieties, better suited to pot culture than other types. These types typically grow no more than 4 feet tall. They flower on new growth so they withstand heavy pruning without a loss in flowers. Lacecap French hydrangea plants typically grow taller than hortensia types, making them suitable shrubbery borders and privacy plantings. These also flower on new wood and tolerate pruning, but their taller growth habit makes them a more challenging choice for container growing.

Growing Locations

• French hydrangeas grow best in USDA hardiness zones 6 through 10, although some more cold-hardy varieties are available that survive in zones 4 and 5. Regardless of zone, hydrangeas need moist, rich soil. The plants thrive with full morning sun and afternoon shade. Too much direct sunlight in the hot afternoon hours causes the plants to lose excessive moisture from their large leaves, which can cause wilting and poor flowering.