Botanical Names: Hydrangea petiolaris
Brighten your shady nooks with the elegant beauty of climbing hydrangea. Known botanically as Hydrangea petiolaris, this vine does what few other vines do: grows and thrives in shade. It also grows in full sun, making it a truly versatile vine in the landscape. Plants benefit from afternoon shade in the Deep South and West, where the sun really sizzles.
Climbing hydrangea attaches to surfaces as it grows, hoisting itself heavenward by clinging to tree trunks, walls or trellises. The clinging occurs courtesy of holdfasts, specialized root structures that cling to surfaces. These holdfasts stick like glue, creating an almost permanent fusion.
Climbing hydrangea works best when allowed to grow on masonry, brick or stone surfaces. You can train it on a wooden surface, provided the wood is rot resistant. Avoid using it against vinyl siding because the holdfasts leave marks and can allow mold to grow on siding. If you plant it ona trellis beside a wall, place the trellis at least 3 feet from the wall. Be sure to use a hefty, substantive trellis that won’t need replaced in a few years. Climbing hydrangea vines are heavy once they’re full grown.
When you first plant climbing hydrangea, it grows slowly, establishing itself underground with an extensive root system. During this time, you may think it’s not growing. An old garden adage states first year, sleep; second year, creep; third year, leap. This saying is very true with climbing hydrangea. It will appear to sleep the first year, will show slow growth the second, and by the third will start growing more obviously, clambering upward. Plants often take three to five years to start flowering.
Give climbing hydrangea a spot with rich, well-drained soil. It’s a good idea to mix compost or other organic matter into soil prior to planting. Although climbing hydrangea grows in full shade, it flowers best when it receives some sunlight. Once vines are established, be sure to mulch the root zone area, especially for vines in full sun. Keeping soil consistently moist is a key to successful growth. In spring, top dress soil around the vine with compost and apply a slow release landscape fertilizer.
Flowers appear in spring to early summer and beckon many pollinators. The flower heads are flat and appear fuzzy. This perennial vine doesn’t really have any pests, although deer have been known to browse leaves and growing tips. The time to prune climbing hydrangea is after flowering. Place cuts to keep the growth under control and confined to the area where you want it.
You can also remove any dead wood after winter, when new growth starts. Take care not to cut into living wood, because this plant flowers on old wood. Prune too deeply in late winter and early spring, and you’ll be removing this year’s blossoms.