If you want to save water, planting the proper plants is only part of the solution. The real keys to water savings are where you place your plants and how you water them.
Plants should be grouped together in “zones” that take into account their water needs, the light conditions and the soil type. Xeriscapes can include low-, moderate- and high-water zones. Each zone should be watered separately according to those needs.
When zoning your landscape, keep in mind how one zone can affect another. High-water plants like Kentucky bluegrass, bellflowers or black-eyed Susans can be planted next to a moderate-water zone of turf-type tall fescue, potentilla or rock cress. Don’t place them beside a low-water zone. Watering the high-water zone will produce overspray that can be used by moderate-water plants. But overspraying into a low-water zone encourages weeds and may even harm the desired plants.
Don’t place a high-water zone next to a sunny sidewalk. This leads to over-watering, because plants are stressed by reflected heat and dry soil. Instead, border your sunny sidewalks with low-water plants.
Zoning can even improve water efficiency for a landscape designed entirely with low-water plants. For instance, on the north side of a house or under trees, choose shade-loving, low-water plants. Put the sun worshippers on a south-facing slope. The two locations will require different approaches to watering.
Want to know exactly which plants fit into the three zones? Visit the Garden Centers of Colorado website, xratedgardening.com. It’s not pornographic petunias or scandalous salvia. The “X-Rated Xeriscape Gardening” program identifies all sorts of plants, from annuals to trees, rating high-water varieties with a single X. Double X plants are for moderate-water zones. The triple X goes to the low-water plants. Ask about the rating system the next time you are in a garden center.
Choose the right plant for the proper zone. Water it according to its needs, and water savings will be yours.
David Winger is a water-conservation specialist with Denver Water.
Xeriscape plants
Looking for low-water plants? You’ll find scads of them in the Xeriscape section of the 57th annual Plant Sale at Denver Botanic Gardens, 1005 York St. The sale is today from 10 a.m. to 6 p.m. and Sunday from 10 a.m. to 4 p.m. Admission is free.
