Summer? Wait, we are just starting to enjoy spring weather. But, now is the time to buy and plant trees, shrubs and perennials to enjoy this summer. Do big blue and pink globes of hydrangea flowers remind you of your grandmother’s garden? If so, come and get a dose of nostalgia or enjoy lots of trendy new hydrangeas . Hydrangea is the featured plant of this year’s UDBG sale and is certainly a trendy plant in the industry. This genus includes a wide range of plants from vines to large shrubs.
Bigleaf hydrangea (Hydrangea macrophylla) is the old fashioned plant most of us remember from Grandma’s garden. This species produces large balls of sterile flowers that are either pink in basic to neutral soils or blue in acidic soils. The added fun of changing soil pH to change the flower color makes this plant unique. There are also lacecap varieties in this group that have a ring of sterile flowers around a center of fertile flowers, looking like a lacecap (duh!).
Panicle hydrangea (Hydrangea paniculata) is another old time favorite. The flower head forms a large cone of sterile flowers with lots of fertile flowers in the interior. Most are white, fading to pink but some new cultivars fade to pink more quickly and retain the pink color longer, even as dried flowers. Panicle hydrangeas bloom on new wood, so they should be pruned in late winter to early spring, for the best blooms.
If you want a native hydrangea, look for smooth hydrangea (Hydrangea arborescens) or oakleaf hydrangea (Hydrangea quercifolia). Smooth hydrangea is not super showy as the straight species, but several showy cultivars are available. Oakleaf hydrangea is a popular coarse-textured plant with exfoliating bark and large globose flowers. Oakleaf hydrangea flowers are white, fading to pink and often hang on the plant all winter, providing interest and structure to the winter garden. Leaves in this species turn a beautiful burgundy color in the fall.
If vines are your thing, there is even a hydrangea vine (Hydrangea anomola spp. petiolaris) that adheres to rough surfaces such as masonry and tree bark. This vine has numerous white flat-topped flower clusters ringed by white sterile flowers in the summer. Use it on a wall next to a walkway where there isn’t room for a shrub or tree.
Hydrangea flowers are great for cutting and drying. Plants tolerate a range of conditions from full sun to full shade depending on the species and cultivar. Many new cultivars have been selected for smaller sized plants with different flower colors and shapes. The UDBG Plant Sale was the last weekend in April but you can still access the catalog for a complete listing and description of lots of great hydrangeas as well as many other plants. Look at the online plant sale catalog by visiting this URL. (http://ag.udel.edu/udbg/events/documents/UDBGCat14_WEB.pdf).
Spigelia marilandica and Hydrangea quercifolia – Oakleaf hydrangea with a native perennial, Indian pink, in the University of Delaware Botanic Garden.