May is the month of irritation. Oops, did I say irritation? I meant irrigation.
Every spring, as the last rains finish, gardeners are busy turning on the drip irrigation timers, and running each valve, to make sure that there are no leaks, and that the water is being targeted correctly. Plants that grew larger since last year may need to have their emitters moved away from the trunk or crown of the plant. Some plants that needed irrigation when they were newly planted are old enough now to get by on their own, and the emitters can be removed completely. Plants that spread underground may actually have overwhelmed their emitters and tangled them in a mass of roots and stems. Sometimes it takes a sharp spade even to find the irrigation lines, and then oops. Now it’s time to repair the line.
This year, because of our record-breaking drought, the stakes are even higher. Almost every garden has room to trim water use.
First of all, if your garden still doesn’t have drip irrigation, now is the time. Overhead watering is so wasteful it should be illegal. Drip irrigation applies the water slowly and evenly directly into the soil, so that none is lost to evaporation or run-off. Every drop penetrates the soil and goes to the roots of the plants where it is needed. Everything you need to install your drip irrigation is available at the Urban Farmer Store, along with free public classes to help you learn what to do.
Next, it’s time to review your watering schedule. Many gardeners water too frequently, but not deeply enough. When we water our plants superficially, they develop root systems near the water, which is mostly in the top layers of the soil. To develop tougher, more drought tolerant plants, try watering deeply but infrequently, encouraging your plants to develop deep, resilient root systems.
After your irrigation has run, take a trowel and actually look... how deeply did the water penetrate? If it has penetrated deeply, and you have chosen appropriate plants, you can probably cut down on the frequency of watering. Have you been watering twice a week in previous years? Try once a week, or even every two weeks. If your soil is good and you water deeply, you may be surprised how long your garden can go between waterings. A thick layer of mulch between established plants can also help reduce the frequency of watering.
By now, most of your garden should be redesigned with plants that are adapted to summer dry soils, plants either from coastal California or from other summer-dry climates all over the world. Plants from South Africa, Australia and New Zealand, coastal Mexico and South America, and the Mediterranean region can thrive here with little or no summer water once established. By moving more to the dry side on your plant choices, you can also reduce outdoor water use. Do you have one spot where you usually plant a flowery patch of thirsty annual flowers? Maybe this year you could try a dramatic, colorful group of sedges and spurges instead.
Most gardening wisdom suggests that we should fertilize our plants after bursts of bloom, and pick off the dead flower heads to force a longer bloom cycle. Unfortunately, this practice also increases the water needs of our plants. Maybe this year it would be better to hold back on fertilizing and allow the plants to set seed after the first round of flowering. This sends a different signal to the plant. Many plants once they have set seed will ‘harden off,’ and slow down their growth or even go dormant. That way they can rest through the long dry season, until the first fall rains wake them up and start them growing again.
But if we give up on deadheading and fertilizing, what will make the garden beautiful in late summer and fall?
This is the real design challenge of summer dry landscapes. Instead of forcing a longer spring by fertilizing, deadheading, and lots of irrigation, let’s think about a beautiful late summer garden in a naturalistic way. First of all, it’s important to include summer dry plants which normally bloom later in the year. For us in California, this includes our native buckwheats, especially St. Catherine’s Lace, or Eriogonum giganteum, whose open habit, silvery foliage, and giant panicles of white flowers create a lasting focal point for the late-summer garden. Now add the tall beautiful grey-green stems of Matilija Poppy, topped by a giant flower that looks like a fried egg sunny-side up. Don’t forget Lion’s Tail, Leonotis leonurus, whose upright posture, sturdy deep green foliage and generous fuzzy orange flowers on tall stems would contrast beautifully with the previous plants. Additional interest can come from late blooming, colorful grasses, like Pennisetum rubrum, and sedges, like Carex testaceae.
Last but not least, let’s all get more buckets (the Golden State Warriors are setting a good example here). I’ve recently started saving water in buckets from baths and showers, vegetable washing and pasta boiling. I’ve chosen one section of the garden which will get no irrigation water this summer, but only reused water carried out from the house. I’ll save money on my water bill for sure, but I also won’t have to pay to join a gym! I’ll get my aerobic and weight-bearing exercise, and accomplish something important at the same time instead of jogging on a machine to nowhere.
It’s very important that we don’t let the lack of available water make us give up on plants. If we just paved the city, we would need less outdoor water in the short run. But this choice would drive climate change by making our city hotter and offsetting our carbon less. A paved city would shrug off winter rain into the sea, while a deeply planted, leafy city would absorb every drop into the water table. It would also break our hearts to pave our city. We are Californians. We think outside the box, create, invent, break old cultural norms (like lawns), and care deeply for the wild. We can create a city that is full of leaves and life, that is sustainable in a desert state, that uses the freshest thinking to slow and eventually reverse the drivers of climate change.