Plant Ideas for Low Water Gardening

The Hardy Plant Society of Oregon is a wonderful organization for Northwest gardeners. There are many programs, plant sales and, of course, open garden directories for its members, a treat indeed to visit a vast array of drool-worthy local gardens. This past Saturday was HPSO's annual fall plant sale and program with guest speaker Fred Weisensee of Dancing Oaks Nursery. His topic was "Preparing Gardens for Climate Change: Building Resilience from the Ground Up". 

From the HPSO website:

Our gardens are already experiencing some stressors from climate change with warmer seasons coupled with more frequent drought. The likelihood is this will only increase so it behooves us to improve our garden's resilience with appropriate plant selection and cultivation. We will explore plants from around the world with low water requirements and heat tolerance that can continue to bring beauty and interest in spite of warmer seasons. We will look at borrowing concepts from regenerative agriculture to help improve soil health and moisture retention while using fewer chemicals.

The presentation was spot-on with many great plants cited. I thought to myself how I actually am quite fortunate as I already have so many of what was on his list planted at Chickadee Gardens. I thought I'd like to share some of these plants as well as a few of my own suggestions so a wider audience may benefit from Fred's thoughtful talk. What follows is a sampling of drought-tolerant plants that will handle our hot summers with aplomb. Most are Fred's suggestions, the rest I have included as I have grown them myself and can attest to their hardiness in tough situations, mainly dry, hot summers with little to no water.

 Eryngium bourgatii, a sea holly, has beautiful variegated, deeply divided foliage that can be seen on the left. This never gets any direct water from me and has survived a move from the old Portland garden, too.

A locally native plant, Eriophyllum lanatum or Oregon sunshine. Fred listed Eriophyllum lanatum 'Takilma Gold', this is simply the straight species and is quite floriferous in spring. The basal foliage is somewhat evergreen, too.

This is Penstemon kunthii, he had P. mexciali 'Red Rocks' listed. Many penstemons, especially west coast natives are drought tolerant. This particular species is basically an evergreen shrublet for us in the Northwest, an easy-care dry garden plant that hummingbirds covet.

One of my own additions, Teucrium chamaedrys or wall germander is not only drought tolerant, but it is an evergreen sub-shrub that can be sheared to shape like boxwood. Here it is seen in full bloom.

Arctostaphylos 'Saint Helena' at about 3 years old.

Pictured is a larger A. 'Saint Helena' about 4 years old.

Foliage detail of A. 'Saint Helena'. Arctostaphylos are pretty much all adapted to our dry summers and wet winters, they are wonderful evergreen groundcovers, shrubs or trees for West Coast gardens. Fred listed A. 'Mt. San Bruno', A. nummularifolia, A. densiflora 'Lynne' and A. x 'Austin Griffiths'. Get thee an Arcto if you do not have one in your West Coast garden!

I have also included Dianthus species as drought-tolerant sun plants. Pictured is D. hispanicus, an incredibly fragrant plant in spring. Its evergreen foliage is an added bonus. Low-growing, they make fantastic edging plants.

Another I've added is Santolina. These are S. chamaecyparis (syn. S. neapolitana) 'Lemon Queen' on the left and S. rosmarinifolia (syn. S. virens) on the right. They really are drought-tolerant and have the same basic cultural conditions as lavender. Looking best after a hard haircut in late winter, they are great mounds of joy for a dry garden.

Detail of S. 'Lemon Queen'

California native Romneya coulteri loves sandy, loose soil. It is difficult to get established in heavy soils (or any soil, really) but once it takes it is reported to be indefinitely wide. Meaning it spreads. But it is lovely and pollinators do appreciate its flowers.

One of my additions, Caryopteris or bluebeard is a semi-woody sub-shrub that leafs out late in the season and also blooms late, as in late summer into autumn. The flowers attract bumble bees (and other pollinators) and its care is minimal. Needing little water once established, I am always so happy to have this in the garden this time of year. Pictured is Caryopteris × clandonensis 'Dark Knight'

Zauschneria or Epilobium 'Bowman'. From the Xera Plants website:

Possibly our second most popular California Fuchsia cultivar as it is more upright but also a free and early bloomer. To 20″ tall the fine green leaves that line the stems make the brilliant orange tubular flowers stand out. Blooms early August to October and spreading underground by stolons to form expanding colonies. To several feet wide- give it room. Ideal in full sun, well drained soil- or on a slope which will further assist in drainage. Brilliant flowers are a beacon to Hummingbirds. Completely drought adapted and requires little if any summer water. Long blooming western native perennial.

An Epilobium that Fred listed was 'Everett's Choice', but just about all of them have similar cultural conditions.

Another of my selections, this is Atriplex halimus. This thing gets the gold star for zero water. But wait, there's more. It's evergreen, it's edible (common name salt bush), it can be cut back to control its large size, and it needs no supplemental water. Oh, and it's gorgeous. After adding it to my garden in 2016 I read that Beth Chatto's garden has them in the dry garden, too. Always pay attention to Beth's amazing dry garden, I say.

On to Ceanothus. Fred listed 'Centennial' and C. cuneatus var ramulosus 'Rodeo Lagoon', while all are similar in their cultural requirements which is full sun, good drainage, un-amended soil. Some are prostrate such as this one, C. gloriosus 'Point Reyes'. Ceanothus fix nitrogen in the soil, a subject Fred touched on. It means that other plants surrounding a nitrogen fixer benefit from being its neighbor. 

A much larger shrub, C. 'Italian Skies' has lovely blue flowers in late spring. There is a Ceanothus for every size requirement and if you can give it full sun and good drainage, I highly recommend these plants.

Cistus, Halimium, and Halmiocistus are a group of related plants that Fred touched on. They are evergreen shrubs with flowers in white or pink (Cistus sp.) or yellows (Halimium) that bloom in spring. They are said to be short-lived, but I find that if they have lean soil and little summer water they last a very long time. They are available in many sizes from ground covers to 8' tall shrubs. It's great that they are an evergreen presence in the garden.

Halimium x pauanum

Halimium 'Sandling'

From the Joy Creek Nursery website:

We have grown Halimium lasianthum 'Sandling' for a decade in one of our no-water borders. It has out-performed almost all of the shrubs growing in that particular border. This mid-sized shrub has evergreen leaves that have silver undersides, Because of the angle that the leaves are held on the stem, the shrub often appears silver. Many gardeners do not like the color yellow in the garden, but the yellow of the flowers of 'Sandling' is so pure and bright it would be hard to dislike it. Each of the five petals that compose the flowers is adorned with a dark red blotch at its base - an eye-catching accent.

May to June.  5 ft. x 3 ft., Yellow flowers, Sun  Zones 8, 9, 10 

Salvia reptans 'Autumn Sapphire' from High Country Gardens is a lovely garden plant blooming beginning in September. Preferring a dry site, it is great for late-season color mixing well with structural plants such as yucca or agave. Fred listed Salvia reptans 'Blue Willow', a very similar plant with the same basic requirements of full sun and good drainage.

Baptisia 'Purple Smoke' and B. bracteata var. leucophaea were two plants Fred listed as great low-maintenance plants for sun. They are also nitrogen fixers like ceanothus. They don't like disturbance, so plant them where you want them and then leave them to establish and you will have a long-lived, carefree plant.

Fred listed Aster ericoides var. prostrata 'Snow Flurry', this is Aster e. 'First Snow'. Asters are amazing late-season color and are wonderful for pollinators. They are easy care and drought-tolerant when established. This one is among my favorites, having a heath like texture, hence the name.

Solidago 'Fireworks' is a very important late season pollinator plant. If you have room for it, it will reach 4' high, straight up, then branch out horizontally like fireworks. You can hear the bees on it as you walk by when it is in full bloom. It stays standing for me through winter and I never *never* water it.

One of my selections, Marrubium incanum or horehound. This is another no water plant that is super easy in full hot sun.

My beloved Muhlenbergia rigens or deer grass, a West Coast native evergreen grass with superb spiky flowers in late summer. This, when lit from behind by the sun, is, in a word, stunning.

Another drought grass is Nassella tenuissima (syn Stipa tenuissima) or Mexican feather grass. Its movement in the breeze is unsurpassed, it's easy, it seeds around but is super easy to pull out if needed and it needs little water.

Festuca glauca 'Beyond Blue' is a sparkling evergreen presence in my garden, especially appreciated in winter. 

Eryngium giganteum or Miss Wilmott's Ghost' is another sea holly that looks great in all its stages. Even after the bloom fades, it turns white then brown but continues to be a sculptural presence for a long period.

I think creeping thymes should be added to the list - so many are great evergreen and drought-tolerant ground covers that smell good, can handle a bit of foot traffic and are edible. Plus, the flowers attract honeybees like crazy. Pictured is Thymus 'Foxley'.

Fremontodendron californicum or flannel bush. A native of California, it is an evergreen shrub that wants absolutely no summer irrigation. Mine has struggled in its new home but I'm determined to get it going. I mean look at those flowers! It's worth it. They get big, though, up to 20' or so I am told. Full sun and good drainage.

Cotinus 'Pink Champagne', Teucrium chamaedrys, Sedum (no i.d.) and Ozothamnus 'Silver Jubilee' are all completely drought-tolerant in a really dry site that receives virtually no summer water and they all look fantastic.

Brunnera 'Garden Candy Sea Heart' has an odd name but is a great dry shade plant. Fred listed Brunnera 'Silver Heart', a similar plant I suspect.

Leptospermum lanigerum 'Silver Form', another of my suggestions, is a drought-tolerant evergreen shrub with silvery leaves and these bonus pretty spring flowers.

Callistemon pityoides 'Mt. Kosciuszko Form' is a small callistemon at only 4' or so high at maturity. An evergreen shrub, this too is a no-water shrub that is just super tough.

Spiraea betulifolia var. lucida, our native spiraea is a deciduous small shrub that in addition to these sweet spring flowers has amazing fall color. Drought-tolerant once established, they are lovely.

Lastly another one of my suggestions, Dorycnium hirsutum or hairy canary clover is a super boisterous ground cover that blooms with these sweet clover like flowers. Its soft gray foliage is a clue that it too is a drought tolerant plant. It is super easy in full sun.

Others that I have from Fred's list but are not pictured include Monardella villosa, Eucomis, Iris foetidissima 'Variegata', Parrotia, Osmanthus rotundifolius, Actaea rubra, Hesperaloe parviflora, and several coreopsis species. 

While I have focused on plant choices that fit with low-water gardening, the talk also included resources about improving your soil, another key point to the presentation. Poor, overly-tilled soil cannot support life, nor does it absorb water like healthy soil full of microbes, fungi and countless other organisms. The key to keeping water in your soil is to have healthy soil. To have healthy soil, pesticides, herbicides, chemical fertilizers and tilling should be avoided and mulches and organic material should be encouraged.

There is much more to this discussion than what I have listed here, for more information here are the resources Fred cited for additional reading and research:

Gabe Brown, (2018), Dirt to Soil - this was the key resource that sparked Fred's interest and this talk

Linda Chalker-Scott (2015) How Plants Work

David C. Johnson. PhDA, Greener Revolution and a No-Regrets Carbon Capture Mechanism for New Mexico

You Tube Videos:

Gabe Brown. (2220), Treating the Farm as an Ecosystem Part 1 the 5 Tenets of Soil Health

Soil Carbon Cowboys

Gaining Ground: Successful No-Till Farmers Tell Their Stories

A Regenerative Secret - Kiss the Ground

Gregory, Phil, The Magic of Soil

The Soil Solution: The Soil/Carbon Connection

Whew, that's a lot of information! It's a great place to start, though, to think about climate change and gardening and how we can positively impact the environment through gardening.

That's a wrap for this week at Chickadee Gardens. Thank you so much for reading and commenting, and happy gardening!