How to Grow Invincibelle Spirit II®
Hydrangea arborescens
No green thumb required! Invincibelle Spirit II® is a type of smooth hydrangea, an easy-to-grow North American native shrub that flowers every year, no matter how harsh the previous winter. Here are the basics you’ll need to achieve success with this plant in your garden:
Hardiness: Invincibelle Spirit II hydrangea is hardy to USDA zone 3 (-35°F, -40°C) and heat tolerant to AHS zone 9 (120-150 days above 86°F/30°C). Don’t know your zone? Find your hardiness zone here.
Site: This hydrangea will do best with a minimum of four hours of sun each day, ideally in the morning. Some direct sun each day ensures vibrant color, abundant blooms, and strong stems. In cool climates, it can tolerate more sun; in hot climates, it will require more shade, particularly in the afternoon.
Soil: Invincibelle Spirit II tolerates a wide range of soils but does best in moist, well-drained areas. It can be grown in potting soil in a large container if you’d like.
How to Plant: Dig a hole twice as wide as the pot, and equally as deep. Do not add anything to the soil at planting time. Situate the plant in the hole with its best-looking side facing outward and backfill the hole using the soil you originally excavated. Water thoroughly after planting.
Water: Hydrangeas like plenty of water, especially their first year or two after planting. Do not allow the soil to dry out completely during its establishment period. You may need to provide supplemental water during periods of hot, dry weather. A 2-3″ thick layer of shredded bark mulch applied over the root zone conserves water, keeps the roots cool, and insulates the roots during winter.
Flowering: Invincibelle Spirit II begins to flower in early summer. The flowers begin a dark burgundy color, open to a rich pink, and gradually fade to a pale pink. Invincibelle Spirit hydrangea has the unique ability to continue blooming up until frost, providing months of flowers! While deadheading is not strictly necessary for the plant to re-bloom, it does encourage it to happen faster. Simply remove the faded flower just above a set of leaves.
Note: Flower size, color, and quantity will increase dramatically as the plant grows into its site. Like other shrubs, hydrangeas require three seasons in the ground to perform their best.
Pruning: The best time to prune a smooth hydrangea is in early spring, just as the buds emerge but before they start to open. Remove any dead flowers still on the plant, along with any thin, spindly growth and any very old and woody growth. Pruning is not imperative but it can encourage stronger stems and a more attractive overall form. You can remove up to one-third of the plant’s total height if you’d like.
Fertilizing: In early spring, apply a granular fertilizer formulated for flowering shrubs (rose fertilizers are ideal) according to package directions. The application may be repeated as the initial wave of flowers winds down if desired.