I have had a climbing hydrangea for 4 years – but it has never bloomed. It is growing but does not produce any buds. It gets full sun and is in good soil. What can I do so it will produce blossoms?
I looked in a few books (including Trees and Shrubs for Pacific Northwest Gardens, 1990, by Grant and Grant) about climbing Hydrangea (Hydrangea anomala ssp. petiolaris) and they all said this vine is wonderful and robust but very slow to establish. You may just have to wait a few more years.
This hydrangea prefers a cool, moist root run so be sure to irrigate it in the summer and place a good mulch (such as compost or wood chips) a few inches deep. The mulch should not touch the trunk of the vine at the top of the soil around the vine. Established trees and shrubs don’t generally need feeding. Avoid using a fertilizer that is high in nitrogen, or it may add lush, green growth at the expense of flowers.
Here is additional information, from Virginia Cooperative Extension:
Excerpts:
“Climbing hydrangeas only bloom on vertical stems so vines growing on
the ground will not bloom. Minimal pruning is required. They bear lacecap inflorescences with an outer ring
of showy white sterile florets around creamy to yellow fertile flowers in late spring. Deadheading can be
done right after flowering to save energy and for aesthetics by cutting the inflorescences off above the first
leaf. Branches that extend out far from the climbing surface may also be pruned back in summer after
flowering to prevent the plants from being pulled from their structures by heavy winds, ice or snow.”
Reasons for lack of flowers on various species of Hydrangea:
- Improper shearing and renewal pruning on H. macrophylla and serrata cultivars
- Frost injury to early expanding growth buds
- Pruning more than a month after bloom time in summer
- Excessive shade
- Excess nitrogen fertilization