Seven Principles of Xeric Landscaping
1. Water Conservation.
The fundamental element of Xeric landscape design is water conservation. Landscape designers constantly look for ways to reduce the amount of costly applied water and to maximize the use of natural precipitation.
Before setting pencil to paper, familiarize yourself with the Seven Principles of Xeriscaping and take a tour of your local nurseries to see what drought-resistant plantings are available locally. A good way to begin is to use 1/4" graph paper, and using 1/4" = 1 ft, draw an aerial view of your property and begin your plan with the following considerations:
• Start by orienting the land by marking down north, south, east and west on the paper. Include any limiting features such as trees, fences, walkways or structures, power poles, etc. Also note the areas of sun and shade, which will help you establish zones of differing water needs as well as sun exposure. It helps to group plants with similar watering needs for most efficient water use, for example, shrubs that need water once a week for 30 minutes.
• Study the natural contours and drainage patterns of the land. These contours can be easily developed into terraces, which add visual interest and help reduce soil loss and erosion due to rain or irrigation. Terraces can be as little as 3" and still offer visual appeal; terraces over 12" will require considerable support, such as rock walls or timbers reinforced with steel stakes.
• Consider the planned use of each area within the plot. Are there some areas for seating, walkways, visual barriers, dining or play--all should be defined and incorporated into your plan. These can be cloud-like areas on your map, just to note the usage.
• Areas to be left as turf should be designed to be accessible and easily mowed. Curved swaths are usually better than straight runs with sharp turns. From a watering standpoint, narrow swaths can be difficult and wasteful to water with conventional sprinklers.
• Larger plantings, such as shrubs and trees, can be positioned to provide natural heating and cooling opportunities for adjacent buildings.
2. Soil Improvement.
The ideal soil in a water-conserving landscape does two things simultaneously: it drains quickly and stores water at the same time. This is typically achieved by increasing the amount of organic material in your soil and keeping it well aerated. Compost is the ideal organic additive, unless your xeriscape contains many succulents and cacti. These species prefer lean soil.
We suggest you begin your project buy having your soil tested at a garden center or by using a home test kit. Most Western US soils tend to be alkaline (high pH) and low in phosphorous. Adding bone-meal and rock phosphate can help.
3. Create Limited Turf Areas
Depending on where you are from, the standard lawns is a Kentucky Blue Grass, water hungry lawn. Consider reducing the size of turf areas as much as possible, while retaining some turf for open space, functionality and visual appeal. When planting new turf, or reseeding existing lawns, ask at your garden center for water-saving species adapted to this area.
4. Use Appropriate Plants
For best results, select plants that are native to your region.
• Use drought-resistant, or tolerant plants. In general, these plants have leaves which are small, thick, glossy, silver-grey or fuzzy - all characteristics which help them save water in a dry climate.
•Select plants for their ultimate size. This reduces pruning maintenance. They may seem small in a 1- 5 Gallon container, but they will grow larger, so plan for the future.
• For hot, dry areas with southern and western exposures, use plants which need only a minimum of water. Along north and east-facing slopes and walls, choose plants that like more moisture, and don't need as much full sun. Most importantly, don't mix plants with high and low-watering needs in the same planting area.
• Trees help to reduce evaporation by blocking wind and shading the soil. Plant now, because years down the road you'll be glad you did.
Cover the soil's surface around plants with a mulch, such as leaves, coarse compost, pine needles, wood chips, bark or gravel. Mulch helps retain soil moisture and temperature, prevent erosion and blocks out competing weeds. Organic mulch will slowly incorporate with the soil, and will need more applied, "top-dressed", from time to time. To be effective, mulch needs to be several inches thick. There should be no areas of bare soil.
Water conservation is the goal, so avoid overwatering. Soaker hoses and drip-irrigation systems offer the easiest and most efficient watering for xeriscapes because they deliver water directly to the base of the plant. This reduces moisture loss from evaporation. They also deliver the water at a slow rate which encourages root absorption and reduces pooling and erosion. In general, it's best to water deeply and less frequently.
7. Maintain your landscape
Low-maintenance is one of the benefits of Xeriscaping. Keeping the weeds from growing up through the mulch may require some attention. Thickening the layer of mulch will help. Turf areas should not be cut too short - taller grass is a natural mulch which shades the roots and helps retain moisture. Avoid over-fertilizing. Ideally, you should be able to enjoy more time relaxing in your yard, and less time taking care of it.