Tips for gardening in the drought

Summer is here, with high temperatures and no rain, and there are more hot, dry months ahead. But that doesn’t mean you need to turn your flower beds into gravel.

We know that lush, green East Coast gardens aren’t suited for our dry Mediterranean climate, which has a regular dry season, usually from June to October. A drought, like the one we’re in, is more extreme, with insufficient rainfall for the entire year. With that in mind, we can choose plants and practices that work with our dry heat.

Here are a few ideas, plus tips to conserve and make the most of the water you use in the garden.

Don’t overwater

Most importantly, don’t overwater. The rule of thumb is that plants need about an inch of water a week. Here, where summertime temperatures can get very hot, you can make that a generous inch, but overwatering is wasting water. Sopping-wet soil is also prone to rot and mildew. And overwatering can cut the oxygen in the soil, which plant roots need to thrive.

To make the most out of every drop, think “slow.” Don’t flood an area or sprinkle the soil rapidly. You want the water to percolate down into the soil rather than flow off the surface into other areas.

By nature, plants have their feeder roots in the richest soil, which is usually the topsoil layer near the surface. The deeper roots are looking for moisture. Sprinkling the soil quickly encourages weak root systems to cluster near the surface but doesn’t force the plant to dig deeply for water.

Also, the best time to water is the morning. This gives the plants time to dry off before the night returns. Watering during the heat of the day means the heat and sun can evaporate much of the water before it gets down to the plant roots.

Irrigation

If you use sprinklers or drip irrigation, curb the flow but increase the length of time you allow the water to run. That way you can water less often but more effectively use less water. It sounds counterintuitive, but it’s not.

If you have irrigation that sprays water across swathes of lawn or gardens, set empty tuna cans or small dishes around the area being covered and see how long it takes for your irrigation system or sprinklers to fill those cans a half-inch deep. Irrigate twice a week for that amount of time each session, and you’ll be giving your plants an inch a week. Be stingy. Don’t overwater.

Or consider switching your irrigation system to a soil moisture-based control system. We now have technology that automatically measures the amount of moisture in the soil and tailors the irrigation schedule to use the minimum water most effectively. These systems usually cost $200 to $300, but they may pay for themselves quickly if your water bills are high.

There are also inexpensive soil-moisture measuring devices that can tell you the level of soil moisture in the garden. You just shove them point first into the ground, and they give you a moisture readout. They cost about $10 each but can give you a heads-up to prevent overwatering.

If you haven’t checked your irrigation system in a while, inspect the areas where it’s delivering water. You may have noticed instances where people are irrigating sidewalks and streets or water is running off lawns and down into a gutter. Adjust your irrigation equipment so water lands only on lawn or garden soil.

Use micro-irrigation whenever possible. These slender tubes, connected to your main irrigation lines, deliver water to selected trees and shrubs and keep them happy without wasting a drop.

There are many irrigation specialists in our region, and you can find them online. What they charge to do the irrigation properly can save you money in the long run.

Irrigation zones

A drought year is not the time to plant a new garden or re-landscape. But if you’re determined to plant or refurbish garden areas this spring, think about irrigation zones.

Plants with similar water needs should be planted together. Each zone represents a specific sun or shade condition which defines the kind of plants in the zone and the appropriate sprinkler or irrigation strategy for that zone.

Prioritize the plants that mean the most to you. This is the time to be ruthless. If you have plants that are water hogs and that you are lukewarm about, you may need to let them go. Direct your precious water resources to the things you care about the most or would be the most difficult to replace. Maybe your vegetable garden wins out because of the food it provides.

The Environmental Protection Agency has published an excellent booklet on how to conserve water in your landscape. You can download a copy for free at bit.ly/3noMNRz. Just type EPA Find It Flag It Fix It into your browser, and you’ll find the link as the top entry.

Another resource, specifically for Californians, is “Beyond Drought-Tolerant” by the people at Sustainable Conservation. It’s a low-water gardening guide full of good ideas and recommendations. You can download a free copy at suscon.org/landing/landing001.html.

Plants

In terms of what to plant, probably the most significant thing you can do is replace your lawn with native and/or drought-resistance plants suitable for “summer dry” climates like Sonoma County.

If you’re working with true North Coast natives, you know your garden will be largely self-maintaining once the roots are established. Ceanothus, coffeeberry, currants, gooseberries, mahonias, monkey flower, mock orange, silk tassel, toyon, wax myrtle, oceanspray and elderberry are some of the common native shrubs. Native trees range from madrone and buckeye to many oaks and pines.

It’s important to ask questions when choosing plants, said Nora Harlow, a landscape architect and author of the recent book, “Gardening in Summer-Dry Climates: Plants for a Lush, Water-Conscious Landscape.”

“People need to know much more about where a plant is from. Where is it native to? What is the soil like? ‘Mediterranean’ or ‘native’ may be what the label says, but that doesn’t tell you anything about the plant,” Harlow said.

There are many other plants that are not native but still suited to our own particular variations of summer-dry climate, including many lavenders, rosemary, artemisias, grevilleas, rockroses, eryngiums, euphorbias, agaves and ornamental bunchgrasses. Manzanita requires hardly any water.

Harlow also favors sage, good if you have a deer problem, native grapes and sugar bush, which can grow to 12 feet, so it needs a bigger garden. But it also grows fast and is deer-resistant.

You might consider adding a rainwater harvesting system. To avoid saturated soils, plant on mounds or in raised beds to guide runoff away from plants that depend on good drainage.