Urban
Agriculture & Gardens
Environmental
landscape design involves selecting slow-growing, drought-tolerant
plants that require less water and maintenance, significantly reducing
water consumption. Native California plants and well-adapted non-native
plants can be combined in wildlife-friendly and visually attractive
landscapes suited to difficult urban conditions.
Lawns require
more water than other plants during dry periods and their use should
be minimized. Currently the City of Santa Monica restricts lawn areas
to a maximum of 20% of the landscaped area, but lower percentages
are desirable. Drought-tolerant groundcovers should be considered
as an alternative to lawn.
The following
principles guide environmental landscape design.
1. Design the
landscape based on a site’s microclimate characteristics - exposure,
wind, moisture, soil types and existing native vegetation. Southern
exposures tend to be the hottest and driest, requiring the most drought-tolerant
plant species. Northern exposures are cooler, require less water and
offer more planting options. Exposed windy areas are drier than protected
areas.
2. Test soils
to determine their nutrient content, organic matter, and necessary
soil amendments. Soils in urban environments commonly suffer from
excessive compaction and depleted organic matter. To promote healthy
plant growth, continuously mulch and compost whenever possible. When
planting in paved areas, provide a continuous soil trench with a minimum
cross-sectional area of 3 sq. yd. to ensure an adequate volume of
rooting medium.
3. A variety of
drought-tolerant native and non-native trees, shrubs, groundcovers
and perennials grow in the Santa Monica region. In most cases they
can replace non-native ornamental plants to achieve the same objectives
of color, texture, shade and seasonal interest. They have the added
benefit of providing fruit and seeds for wildlife.
4. Add mulch and
compost to soils at least once a year to continuously add nutrients
to the soil. Mulching reduces water use by reducing evaporation and
runoff by 75% to 90% over unmulched planting areas.
5. Install efficient
drip irrigation systems that deliver water directly to the root zone
in measured amounts to reduce water consumption by 50% to 70%. Use
low-volume, low-angle, pop-up sprinkler heads for lawn areas. Use
separate zones for lawn and planting areas to match watering requirements
and provide longer duration watering cycles to encourage deeper rooting.
6. Utilize permeable
paving and slope walkways toward landscaped areas wherever possible
to encourage water infiltration and air exchange, and reduce the need
for irrigation.
7. Avoid fertilizing
and pruning during dry periods, as these activities stimulate vegetative
growth and increase water needs.
Cautions
- Provide adequate
quality and quantity of soil.
- Drip irrigation
systems are essential for plants to become established.
- Expertise in
environmental landscape design and maintenance is highly recommended.
