by Owen E. Dell
It’s a remarkable moment in the history of landscaping. People are beginning to look at the impact of their gardens and are realizing that they can have a beautiful landscape without making excessive demands on the environment. You might call it the “Post-Xeriscape Era,” since we’ve come to understand that there’s more to having a low-impact landscape than just saving water.
Today, we look at the things that flow into and out of a landscape and try to minimize their use. For example, a typical garden requires a number of resources for its construction – concrete, lumber, plants, compost, PVC irrigation pipe and so forth. There will be additional inputs needed for the maintenance of the garden, such as water, fertilizer, fuel to operate power equipment, pesticides and herbicides, to name a few. A garden also generates materials that may be harmful to the environment, such as lawn clippings, tree and shrub prunings (collectively referred to as “greenwaste”), polluted runoff of chemical-laden water and others. The idea behind sustainable landscaping is to develop ways to reduce these inputs and outputs without sacrificing beauty, economy and ease of maintenance.
As you’ll see in this article, a sustainable landscape can actually be less costly and easier to maintain, because it’s designed correctly. Far from being a sacrifice, developing a sustainable landscape can bring you rich rewards and beauty you may not have thought was possible. Enjoy this brief introduction to sustainable landscaping and please call if you have any questions.
When selecting materials for the construction of your landscaping, first consider re-using things such as railroad ties, broken concrete for walls and other cast-offs. Use your imagination and remember that rustic materials often look great in an outdoor environment.
Next, think about recycled products. One of the interesting new materials available is plastic “lumber” made from recycled milk and soda bottles; it’s attractive and durable and comes in a number of colors.
Where you must use new materials, make renewable resources your first choice. Even natural materials can be a problem. For instance, decomposed granite is strip-mined from natural or formerly natural areas. Remember too that even renewable materials come from somewhere – using redwood lumber means trees had to be cut down.
Reduce the use of decks made from redwood, high-tech patio furniture and other consumptive goods.
Always ask yourself, “Where did this come from?” If you don’t know the source of something, ask questions.
Whatever you use, be sure it will be durable. Build to last. It’s better to use more materials doing something right than to cut corners and have to re-do your work in a few years.
Select from among the hundreds of varieties of attractive water-efficient plants, many of which have become available only in the past few years. Use native species whenever possible, or plants from other Mediterranean climates.
Plant less densely – don’t try to fill up every square inch with plants. This will balance the biomass – the quantity of water-using vegetation – with the available rainfall. Reduce lawn areas to just what you’ll actually use. One thousand square feet of lawn or less is adequate for most families. Beware of claims about “drought-tolerant” or “low water-use” lawn grasses – there’s no such thing. Hybrid bermuda grass is the lowest water-use turfgrass variety on the market, but it still needs quite a bit of water, compared to water-efficient landscaping. Considerturf a luxury best used in moderation.
When you plant, incorporate organic material into your soil to improve its water-holding capacity. Your own compost is best, but there’s rarely enough to go around. Buy the best quality compost and make sure it’s nitrolized to prevent damage to your new plants. Avoid wood shavings, sawdust, fresh manures or mushroom compost.
Most controllers make you water every week or two and that’s too much for many drought-tolerant plantings. There are valves available that can be set manually and will shut off after delivering a set amount of water – this is often a better approach for drip.
After planting, be sure to apply a mulch on top of the soil. You can use bark, crushed rock or other attractive materials. Mulch helps keep the soil from drying out, discourages water-stealing weeds, hides drip tubing, keeps the dust down in summer, provides a safe walking surface and looks better than bare ground.
‘Be sure your irrigation system is efficient – design your lawn sprinklers so they don’t apply water faster than your soil can soak it up. Place sprinkler heads so they will water only the lawn, with a minimum of overspray. Use drip for everything but lawn areas. Avoid planting sheets of herbaceous ground cover that must be sprinkled; use individual plants and a drip system instead. Drip systems use a tiny fraction of the water that sprinklers do.
Use a controller for the lawns – it can be cycled to prevent runoff and save you the trouble of turning valves on and off all the time. For the drip system, think about whether you want a controller or not.
To conserve rainfall, use permeable paving or slope paved areas towards planted areas. Consider grading to allow rainwater to pond and soak in (make sure this won’t cause erosion problems).
Finally, don’t overwater. Check soil moisture before irrigating and apply only what the plants actually need.
Choose plants that don’t require a lot of fertilizer to keep them healthy, and that are naturally resistant to pests and diseases. This will reduce the need to feed and spray. When you do feed, use organic fertilizers or, even better, compost produced from your own trimmings. Use safe pesticides or biological control methods such as beneficial insects that prey on pests.
Fossil fuels are used to deliver materials to the site, to transport workers (including gardeners) to and from the job, to operate power equipment such as mowers and chainsaws and to haul away refuse. A less obvious use of fossil fuels is in the production of fertilizer and many garden chemicals. Sustainable landscaping reduces these demands.
Landscaping can also reduce energy use inside the home. Properly located shade trees can provide climate control, reducing heating and cooling costs. Trees and shrubs used as windbreaks can also moderate the microclimate in and around the home.
Landscaping can provide or enhance habitat for wildlife by supplying food, shelter and nesting materials. (Remember to preserve natural areas whenever possible.)
Finally, landscaping can mitigate fire hazards by providing greenbelts of low-fuel vegetation around homes.
Sustainable landscaping is based on common sense and good design. It’s about stability – creating something that works because it’s in harmony with the local environment and has an internal system of checks and balances. It’s not perfect – you’ll still need to use resources, but in a much more sensible way. Done right, landscaping can be a part of the solution, not part of the problem.