by Cindy Watter

I first noticed this dramatic shrub when I was walking around in downtown Napa.  The Napa Square building had a few in enormous pots.  Later I saw them at the Hatt Building, as part of the hotel's spectacular landscaping. I put one in my front yard, and after a few misadventures, couldn't be more pleased with it.

The oakleaf hydrangea (Hydrangea quercifolia) is a native North American plant.  Unlike the familiar varieties, it is interesting looking all year long. The lobed leaves turn rosy red in the fall, and the branches turn bronze and peel a bit.  It likes some sun, but will flourish in mostly shady areas.  It can grow ten feet tall, and its ten-inch long, spiked creamy flowers are attractive.  If you want a statement, this is one. The bonus is the oakleaf hydrangea requires, at most, half of the water conventional hydrangeas demand. After ten years, I only water mine when it has a visible droop, which is maybe once a week in summer. And in case you are worried about pests – it has none. 

Plant it in soil that has been loosened and enriched with compost, because it prefers well-drained soil.  This plant does not require fertilizer, but it likes worm compost.  The only tricky part of this plant is pruning it.  Once I slashed it almost down to the ground, and discovered that I had cut off all the buds for next year's flowers.  It still grew to an enormous height and looked nice without flowers.  The next year I took "prune for shape" too literally, and, in the spring, discovered that I had cleverly ended up with flowers INSIDE the foliage.  They were visible when the wind blew, which is rather coquettish, like a lace petticoat peeping out from under a hem, but not the effect I wanted. 

I learned that buds grow on the previous year's growth, so don't prune back too much. You should prune them after they bloom, but you can leave the flowers on for a while, because even when they are dried out they look good.  Then you can cut them off, and do a real pruning in the early fall.  Take a good look at the stems – if you see buds forming next to a leaf, prune above them. 

I have become a real fan of the oakleaf hydrangea.  It needs little care and even less water, which is perfect for our increasingly dry climate.  It is also quite elegant and adds curb appeal to a yard with no lawn. 

Master Gardeners are following recommended social distancing guidelines that keep everyone safe, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credits: Cindy Watter

Informational Links:

UC IPM http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/hydrangea.html

UCMG Napa County http://napamg.ucanr.edu/files/262307.pdf

UCMG Sonoma County http://sonomamg.ucanr.edu/Plant_of_the_Month/Hydrangea_quercifolia/

Monrovia https://www.monrovia.com/oakleaf-hydrangea.html