Reform a guzzler garden

Credit: iStock/ ChrisSteer

Carol Pope:

How does a gardener “reform” a guzzler garden? Are there quick fixes or is the gardener required to rip everything up and start from scratch?

Mary Ann Newcomer:
Paul put it very succinctly when he said its all about plant selection and soil preparation.

I am in the process of doing this in my garden. I believe a careful, well thought out approach is generally the best approach.

Generally, the single biggest water guzzler is the turf, particularly Kentucky blue grass lawns. I am removing one section of mine per year/growing season. I am replacing the turf with garden beds and wide, well-draining pathways (four feet wide).

The remaining sections of turf, I aerate once or twice a year, top dress with a fine layer of organic compost and monitor the sprinkler heads for efficiency. This is very affordable.

When I am designing gardens for clients, if they insist on a section of turf, I insist they use one of the patented varieties developed specifically for our region (Boise, Idaho): deep-rooted, waterwise varieties, with the ability to withstand our summer temps of 100+° F (38+° C).

Start replacing water-hogging plant material a little at a time, but as much as you can afford. Check with your local nurseries for recommendations of waterwise plant material. You may be surprised to discover some of the most romantic, old fashioned heirloom plants are extremely drought tolerant: tall German bearded iris, old and antique roses, daylilies and tigerlilies, just to name a few.

I also tell folks to pick up a couple of bags of compost (great if they make their own) and top dress/add to their gardens beds as often as possible.

Paul J. Tukey:
That’s a difficult question for a general answer. One would have to first evaluate the plants and the soil. In general, however, there are some techniques and products that can allow a landscape to transition rather than be completely overhauled. I like to use compost as a mulch each year, which will eventually incorporate itself into the soil to create the “sponge” factor that allows the soil to hold on to water. Drenches of compost tea or liquid extracts of humates or seaweed will also increase the “cation exchange,” allowing the soil to hold on to water and nutrients.

Beyond that, one would need to go plant by plant to evaluate the water needs of each. Beds of annual petunias, for example, are going to require a lot of water—even in rich, fertile soil. Sedums, daylilies and Shasta daises, on the other hand, will do quite well with minimal water once established.

In general, gardeners will be amazed how much a blanket of organic matter will do for their waterwise gardens.

Nan Sterman:
I teach a class I developed here in San Diego for the Water Conservation Garden called Bye Bye Grass. It is about how to get rid of lawn and what to replace it with. It is extremely popular. At the start of every class, I ask people why they came and what inspired them to get rid of their lawn, and they always say “to save water.”

A few quick fixes:

• Stop watering. Most people way way overwater just because they expect that if a little is good, a lot is better. Nothing could be further from the truth. I tell people to turn their water off, zone by zone, and wait until they see the first plant start to look droopy. That time, minus a day or two, tells you how long that zone can go without water (of course, it changes from season to season). Usually, people are shocked by how long a time that is.
• Tune up your irrigation system. Flush the lines, be sure the spray heads are working properly and aimed properly, replace popped drip heads, fix the leaks, etc.
• Finally, my mantra is “mulch, mulch, mulch.” Mulch is the one silver bullet in the garden. It does wonders for the soil, supports beneficial microbes, keeps the weeds down and insulates the soil from water loss. My garden has a “no bare dirt” policy. Yours should, too.

Mary Ann Newcomer:
Paul, I have a question for you. I read somewhere that increasing the organic matter in your soil by X amount increases its water retention capabilities by X amount. Do you know those general numbers?

Paul J. Tukey:
I believe I’ve read exact numbers like that, too. I can try to find them. The addition of organic matter will have a dramatic effect in sandy or silty soils when it comes to water retention. If a soil is predominantly clay already, though, the organic matter may actually help the soil shed water more readily—which in some cases is a good thing.

Mary Ann Newcomer: Yes, even a small percentage increase in organic matter in your soil will result in a substantial increase in your soil’s ability to retain water.