Annabelle (Hydrangea arborescens Annabelle) is a deciduous shrub native to the United States. Northern gardeners love Annabelle for its cold-hardiness, while southern gardeners prize it for its reliable blooming habit. With huge white blooms, several Annabelle hydrangeas make a striking hedge; a single Annabelle provides a soft, old-fashioned accent in the shade garden. Annabelle is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9.
Grow Annabelle in full sun if you live in the northern regions of the United States. Other gardeners should provide dappled sunlight or afternoon shade. Avoid planting hydrangeas under trees so they will not have to compete for moisture and nutrients.
Amend the soil in which Annabelle is growing if it doesn’t drain adequately. Pine-bark mulch or sphagnum peat moss mixed into the soil will make it drain more quickly
Spread 3 to 4 inches of mulch on the soil around an Annabelle hydrangea. Keep it 5 inches away from the wood and spread it out 1 foot beyond the drip line. Remove the mulch in the spring before fertilizing and add a fresh layer after fertilizing.
Water Annabelle when the top 2 inches of soil is dry. On hot days the plant may wilt, which means it needs water. After watering it should perk up.
Fertilize Annabelle in spring with a 3-inch layer of well-rotted manure spread on the soil beneath it. Spread the manure to the drip line.
Provide support for large Annabelle shrubs, which otherwise may fall over in wind and rain. Multiple Annabelles planted closely together support each other. Planting one or more next to a fence also provides stability.
Prune Annabelle to a height of 18 inches in fall. This will help strengthen the stems that grow in the spring. Also cut off any branches that are crossing over others and any dead wood.