Tuesday, August 2, 2011

Coastal Shrub Focus: Hydrangea

As a coastal homeowner, it can be challenging to create an attractive landscape that stands up to the climate and doesn't demand endless hours of maintenance.  Let's face it, people buy homes at the coast so they can enjoy the beach... not spend weekends doing yard work.

After trees, the selection of medium- to large-sized shrubs is critical in designing your landscape.  These large living elements provide the bones for your outdoor space.  With a limited palette of shrubs that can survive and thrive on the coast, it's worth noting one standout that can perform.

Hydrangea macrophylla, the common Mophead Hydrangea, offers many benefits.  This dependable shrub is largely pest- and disease-free, requires infrequent and simple pruning, provides long-lasting bloom with outstanding color, needs little supplemental water, and can serve as a medium-sized foundation shrub.  As a bonus, the flowers can be cut for inside arrangements and even dried for winter.
H. macrophylla 'Nikko Blue'

Hydrangeas are a familiar shrub to inland gardeners, but often present the added burden of regular summer watering.  They tend to get crispy around the edges and the flowers wilt in too much direct sun or high temperatures... which makes the coast an ideal climate for hydrangeas.  Our mild summer temps and misty cool mornings, along with high levels of organic matter in the soil to retain moisture, help to create a perfect setting.

Believe it or not, most coastal hydrangeas receive no supplemental summer watering and perform just fine.  In my front yard, a stunning hydrangea receives late-afternoon reflected heat off a west-facing wall, so I will give it a little water once or twice a week. Even if I forget, the shrub will just droop a little in late afternoon and perk right back up in the evening.

One of the best coastal features of hydrangeas is their ability to withstand our drying winds in summer.  The damaging winter winds don't affect them at all since the leaves have already shed in late fall.  On many coastal landscapes with direct ocean winds, I have seen hydrangeas survive where most other shrubs fail.  Give them just a little shelter for best performance, something to filter the wind like a picket fence or a shore pine.

Picking the right color is one of hydrangea's challenges.  The range of color is basically white-blue-purple-pink.  Occasionally you will find hydrangeas with greenish flowers, and one unusual variety called 'Quickfire' actually changes color during the bloom, from a white to reddish-pink flower.  Oakleaf hydrangeas (Hydrangea quercifolia) generally sport white flowers but offer the additional benefit of oak-shaped leaves with remarkable fall color.  Another popular choice for different texture is the elegant group of Lacecap Hydrangeas, with their delicate blooms.
Lacecap Hydrangea - Flickr.com

Part of the reason color is a challenge with these shrubs is that soil acidity and mineral availability will shift the final hue.  You might for instance purchase what appears to be a pink-flowered hydrangea that in later years moves toward blue or white, a result of our high soil acidity.  A good resource for purchasing and learning about hydrangea color and proper fertilization is Oregon grower Hydrangeas Plus.  Alternatively, buy your shrub from a coastal nursery and ask questions about which ones perform best.

The other main challenge with hydrangeas on the coast is deer protection, yes even in the city.  Lincoln City, for example, has a substantial deer and elk population and hydrangeas are a preferred snack.  My favorite way to protect them is with a deer-repellent spray such as Not Tonight, Deer or Liquid Fence.  Be sure to wear some clothes and gloves you don't mind getting smelly, as the repellent is odor-based.

Other less-common types of hydrangeas include a climbing vine (Hydrangea anomala var. petiolaris) and the taller tree-like species known as PeeGee Hydrangea (Hydrangea paniculata 'Grandiflora'), which grows to 15' tall.


  1. I love the name Not Tonight, Deer. Great post. Thanks.

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