This summer really got me thinking. Should summers like that of 2015 become frequent, just how much yard am I interested in watering? I let some areas go dry this year, out of sheer exhaustion combined with a sense that it’s inappropriate, with all of Oregon in a state of drought, to have sprinklers going all the time. Some areas I placed on a regular but restricted water regimen. It has been interesting to see what survived and what did best.
Not all surviving plants survive for the same reason. Some may simply have been in the ground longer than plants that bit the dust. In my garden, a few have undoubtedly reached unseen reserves of moisture underground. Shade preserved some plants that would not have survived in full sun.
Others, though, appear to be genuinely drought resistant. This has got me wondering — what kind of a garden could I achieve if I watered just a few times a summer, or not at all? My native patch, despite a few casualties, looked rather attractive in premature autumnal shades of tan and brown and has even had something in bloom at all times, but we do worry that it may be a fire hazard.
Close to the house I’d prefer something greener and a little more controlled, with a smaller volume of tinder-dry biomass. I’ve begun to list some principles and strategies for a yard that would significantly cut down on watering but would look alive and well in all seasons.
It is easy enough to have a spectacular spring garden. Many of the bulbs we grow in gardens originate in the Mediterranean and Middle East, and they actually prefer dry conditions in summer. The same is true of our own Pacific Northwest native bulbs. Collectively, bulbous plants bloom from January through October or November, and individually have a green and growing period some time from October through June. Most are dormant through the height of summer. Other plants with a pronounced summer dormancy include certain hardy geraniums, Oriental poppies, bleeding heart, false Solomon seal and Siebold’s primrose.
So here’s a strategy: Combine summer-dormant bulbs and other plants that bloom in spring and fall with strategically placed, drought-tolerant shrubs and perennials. A low-water regimen should make it easier to grow the many shrubs and perennials that are adapted to dry summers. That includes ceanothus, manzanita, PNW iris, penstemon and some of the hardier natives from Australia and New Zealand.
Plant and divide in fall, and do your weeding fall through late winter, while the soil is moist. When plants go dormant in early summer, clean up desiccated foliage and mulch neatly. Await the arrival of fall-blooming bulbs such as hardy cyclamen, belladonna lily, colchicum and true fall crocus.
Some annuals (love-in-a-mist, for example) complete their life cycle by early summer, and their dried stems and seed pods are attractive for months. Put summer flower power where you most need it and where it is convenient to provide water.
Summer-blooming annuals and lush foliage plants may be confined to strategically placed containers. It’s also worth noting that, while all actively growing container plants need regular water, some are content to dry out in between waterings. Geraniums (pelargoniums, that is) don’t mind it, nor do penstemon and agapanthus (lily of the Nile). I’m sure there are many more.
Leaky hoses or drip lines, preferably underneath a mulch, can sustain perennial food plants — fruit trees and bushes, rhubarb, sorrel and herbs — in areas you don’t otherwise irrigate. You will need to experiment to find the duration and frequency of watering that’s best for your soil and your crops. (Strawberries get by with less water than I expected; blueberries need all the water you can give them. Fruit trees need a lot.)
Come September, fallow areas between irrigated plants can be perfect for sowing small fall and winter greens as the weather cools, or for those extra starts of broccoli and kale. Give summer-dry areas a good soak in early September before you attempt to cultivate the soil.
I’m currently planning a new kind of perennial border that omits water guzzlers but still provides a colorful show in summer. Penstemon, agastache and sedum, along with some torch lilies, salvias and asters, will get by with the occasional deep soak. For more ideas, mine the internet. I especially recommend xeraplants.com, the website of Paul Bonine’s excellent Portland nursery. It provides helpful lists of no-water and low-water plants. Just remember that all plants need regular water until they become established.