Editor's note: This is the second in a three-part series on how to plan, design and plant a waterwise garden or landscape in the Rim country.
by Barb Bourscheidt
If you're starting a garden plan with a vacant lot, you're only limited by your imagination and your resources.
Most gardeners, however, don't start with a clean slate. They've bought a home from someone who had their own ideas about landscaping and gardening.
Or, perhaps, their own gardening philosophy has changed and the garden design they created in the past is now ready for updating.
Whatever the case, the key to any successful low-water-use garden is a six-step process that starts with planning and design and is followed by soil preparation, plant selection, water system installation, mulching and maintenance.
Begin by assessing your property. Use a sketchpad, graph paper, pencil, ruler and measuring tape to make a rough drawing of your lot. Outline your house, note compass directions and existing features such as a pond, trees and patio.
Which areas are sunny, shady, windy, naturally wet?
Next, think about how you use your outdoor living space. What are your needs? Vegetable garden? Hammock? Dog run? Barbecue and outdoor dining area?
Where are the best locations for these activities? Which areas need landscape plants? What are the planting area conditions? Note soil type, number of hours of sunshine each day, and established plants with which new plantings will share space.
Is a lawn really necessary, or will alternative types of surfacing work just as well? Where will ground covers work?
Create zones for water use.
1. Use the plants that are most important to you and that may require the highest amount of water near the house. This is called the "oasis." By harvesting water runoff from the roof, and utilizing the cooler north and east exposures, plants that would naturally grow in shadier or more sheltered environments will thrive.
Deciduous trees planted on the south and west will shade your house in summer and allow the warmth of the sun in winter. This practice saves not only water but also other precious resources such as gas and electricity.
2. In the transition zone at the outer edge of the oasis, create an intermediate-water-use zone. Use plants here that require infrequent supplemental watering -- less than once a week. If you need a large lawn area, consider planting buffalo grass or other native grasses here.
3. At the outer edge of your planting area, create an arid zone using drought-tolerant vegetation. Once these plants are established, there should be no need for additional watering. If you have a native plant buffer on the perimeter of your property, leave it in place, or plant natives from this climate zone.
Remember, however, that just because a plant occurs here naturally, it may not be suited for the place you've selected for it. Find out if it naturally grows in a wet place or on a hot rocky slope, for instance.
Watering zones are most successful with the use of low-pressure drip irrigation systems. A separate water supply line should serve each of your plant zones. This will provide even watering for all of your plant types.
Trees are usually best placed on their own water supply line because they need to be watered longer than other plants. You can control the amount of water each plant receives by using adjustable-rate emitters or by adding drip emitters to the planting.
Modern irrigation timers are sophisticated enough to adjust for most other contingencies.
Take care to adjust watering times and amounts according to the seasons and climate conditions.
Over-watering a waterwise landscape is one of the most serious mistakes inexperienced gardeners make.
Next, design your "Hardscape." This concept includes driveways, pathways patios, decks, garden structures, boulders, ponds, etc. Each of these elements provides an opportunity for additional harvesting of run-off, and will add interest and function to your overall landscape.
Design planting areas by defining borders, deciding whether to use border material, raised beds and stepping stones. Note the location of hose bibs for your watering system, and electrical access for timer installation.
The theme here is to use waterwise techniques and pick plants and other features that will create a natural look. By using plants that are suited to this climate zone, we can all help preserve our environment.
Next week: "Plants for the water-wise garden."