Growing Hydrangea arborescens

Latin Name Pronunciation: hye-dran'jee-uh 

Growing H. arborescens

Light/Watering: Most varieties thrive in full sun in the North, but in the South require afternoon shade. Moist soils that do not dry out are best; do not plant in hot, dry, exposed sites. Mulch to conserve moisture and buffer soil temperatures.

Fertilizer/Soil and pH: Fertilize once in spring with a fertilizer designed to encourage blooms (such as 15-30-15). Soils should be moist but well drained, and rich in organic matter.

Pests/Diseases: None serious. Occasionally powdery mildew will infect the foliage, especially in humid areas with poor air circulation. Treat with an appropriate fungicide if the problem is serious, and be sure to rake up and destroy all fallen foliage in the autumn.

Pruning: In early spring, cut stems back by about one-third their total height, which builds a strong woody base. Hydrangea arborescens blooms on new wood.

Reflowering: You may cut the first flowering stems of H. arborescens and hang to dry for arrangements; rebloom may then occur in August or September.

Transplanting: Young plants may be transplanted when dormant in early spring; larger tree-form varieties are difficult to move once established, but it can be done. Prune top growth after transplanting to reduce water loss.

End of Season Care: Rake up and destroy any fallen foliage that was infected by powdery mildew or other fungi.

Calendar of Care

Early Spring: Cut stems back by about one-third their total height, which builds a strong woody base while also encouraging abundant new growth for lots of flowers and a lush, full look. Feed plants with a fertilizer high in phosphorus (such as 15-30-15) to encourage blooms. Complete any transplanting before leaves unfurl.

Mid-Spring: Mulch plants after soil has warmed to conserve moisture and buffer soil temperatures. Watch for powdery mildew and treat as needed.

Summer: Cut flowering stems from H. arborescens and hang to dry if desired.

Fall: Remove and destroy any fallen foliage that was infected by powdery mildew.

For more information on growing Hydrangeas, click here.