Hydrangea macrophylla "Penny Mac' is best grown in rich, medium moisture, well-drained soils in part shade. Tolerates full sun only if grown in consistently moist soils. Soil pH affects the flower color of most cultivars except white (blue in highly acidic soils and lilac to pink in slightly acidic to alkaline soils). Add aluminum sulfate to the soil to make the flowers bluer or add lime to the soil to make the flowers pinker. Begin soil treatments well in advance of flowering, as in late autumn or early spring. Plants generally need little pruning.
If needed, prune immediately after flowering by cutting back flowering stems to a pair of healthy buds. Prune out weak or winter-damaged stems in late winter/early spring. Best to mulch plants year-round with 3" of shredded bark, peat or compost. Winter hardy to USDA Zone 6.
Penny Mac blooms on both old and new growth and is winter hardy to USDA Zone 5, all of which means that the plants will, within this growing range, reliably flower each year, regardless of winter temperature, and do not need to be covered with burlap in areas such as St. Louis.
Shipping (bare root) image of the plant that is shown.
