How was your water bill this summer? $200? $300? Over $500? Was it higher than usual and worse than expected? While the cause could be anything from a leaky toilet to an inefficient washing machine, chances are your landscape may have been the main culprit.
Whether you have an automatic irrigation system or hand water using a hose, every drop costs you money if you use a public water source. (For those of us with wells, the issues are somewhat different: I have to minimize summer watering to be sure our well doesn't run dry and impact our neighbors as well as ourselves!)
After three months without any measurable rain here in Duvall, Washington, and temperatures consistently in the 80's and 90's with several days over 100', my garden struggled. I could hand water some areas but many plants were left to their own devices because they were beyond the reach of my hose and/or available time. My clay soil bakes as dry as a cracked riverbed in summer although a top dressing of Fertil Mulch in spring does help conserve moisture to some degree.
While the majority of the plants in my garden have been selected for drought tolerance (as well as deer resistance) some have done better than others, especially as this is the second such extreme summer in a row. Some varieties of barberries and spirea started to defoliate by mid-August for example, and all my pines were showing signs of stress by September. Exbury azaleas turned crispy and shed leaves last month and my poor katsura tree (which is most definitely NOT drought tolerant) has been dropping leaves since August. Others surprised me by their 'can do' attitude and those are the survivors that I'll share with you here, focusing in this post on trees and shrubs. I'll cover perennials and annuals next time.
The plants highlighted below received NO supplemental water between mid-June and mid-September. They are all planted in the ground (not containers) and were not fertilized in any way. Consider replacing some of your thirstier garden plants such as rhododendrons and hydrangeas to save water, energy and money next year!
Forever Goldie golden arborvitae
I have two of these in the garden, one planted five years ago and the other two years ago. Both look as fabulous today as they did in May – no signs of leaf scorch or stress whatsoever and shining like a beacon in the garden. Highly recommended! Details and order here or ask for it at your local nursery.
It never even occurs to me to water my Japanese snowbell (Styrax japonica), yet it had the best floral display ever this June and has shown no signs of premature leaf drop or stress since then. You need to include this beautiful small tree for the fragrant spring blooms alone!
Other trees worth mentioning
My well established Japanese maples, Hinoki cypress, river birch, Armstrong maples, weeping willow and Persian ironwoods all did well too. Presumably their root systems are deep enough to reach moisture.
Blooming their socks off, healthy leaves and generally looking fabulous, I have a few different varieties of hibiscus in two locations, both planted last summer. Those that received NO summer water look as good as those which got a weekly soaking – lesson learned!
I had a new variety to test for Proven Winners this year: Beyond Midnight. Since it was only planted this May I did water it just twice during the entire summer but have included it here because it looks so fabulous! An abundance of blooms, healthy leaves and lots of new growth – I'm impressed. Click on the link for details
One of those 'test' shrubs from Proven Winners that I tucked into a far border and promptly forgot about! Well beyond the reach of any water source and too far away to lug a watering can, this Aphrodite sweetshrub is a real survivor! It has had blooms non-stop from May until now, has grown several feet in width and height and shows no sign of having endured a tough summer. A winner on all accounts! Details here
With many varieties in multiple locations, some planted five years ago and others just this spring, I can tell you these may actually be the most drought tolerant of all my shrubs. Not a single plant looks stressed regardless of age or location.
Like weigela, I have four unique varieties of smoke bushes (Cotinus sp.) in five different locations, ranging in maturity from two to five years in the ground. While a few lower leaves did drop, overall the shrubs look fabulous.
Pictured here are Golden Spirit, Grace, Royal Purple and Old Fashioned. Click on the links for details. Note: I coppice my mature shrubs to 2' tall in sprung to keep them to a dense shrub form, sacrificing the smoke (flowers) in favor of larger leaves.
Pearl Glam beautyberry
Another winner from Proven Winners on so many levels! While they have not put on a lot of growth this year, the two one-year-old shrubs have did bloom and berry well, and still look good without watering. Details here
I may have watered this a couple of times during the summer, but only because I happened to pass by it with hose in hand on my way to thirstier plants in the same bed! I am confident that this is a keeper as far as low-water use goes. Gro-Lo sumac (Rhus aromatica 'Gro-Lo') has outstanding fall color to look forward to also.
Other shrubs worth mentioning.
Other shrubs that did well without any water, and which are evergreen include Rheingold arborvitae, Goshiki Japanese holly, Oregon grape, abelia (mostly semi-evergreen varieties for me) and Rainbow leucothoe.
I hope these insights will help you plan for a lower maintenance and less costly summer in 2018!
Further inspiration and reading
My two books include many combinations featuring the plants mentioned here. Although neither publication focuses strictly on drought tolerance, they both indicate the watering needs of each plant.
Also explore the following titles, especially if you live in a different climate:
(Note that these affiliate links save YOU money – and earn me a few pennies too.)