Native Plant Gardening: Getting Started

By Nancy Heuler, MLA

Have Space, Dirt, Water – Now What?

Creating a home garden with California native plants can be fun and rewarding, while bringing wildlife and an authentic sense of place to your garden. Also, including certain drought-adapted plant communities can result in water savings and lawn replacement has become a growing trend throughout the state. But once the lawn is gone, then what? Here is a crash course in garden design. The same principles can be used with any design, but with locally adapted California natives, we pay special attention to appropriate soils, watering regimes and plant communities.

Here is a crash course in garden design

First analyze the existing site: Determine if the soil texture from a 4”-6” depth is sand, silt, or clay or a combination.(Loam is an equal combination of all three.) If a moist sample sticks together when squeezed, it contains more clay; if it falls apart, it contains more sand. Soil texture affects drainage rates, water needs, oxygen availability and fertility. To determine the drainage rate, dig a hole, fill it with water and see how long it takes to drain. Clay takes longer to drain, while sand drains fastest.

On a diagram, note slopes, views that could be screened, borrowed or framed, shade/sun patterns as they change throughout the year, human uses and circulation requirements, legal setbacks and codes, and existing trees to keep. If near wildland, the landscape elements will have to conform to local fire codes (e.g. flammable invasive vs. fire-resistant non-invasive plant species, spacing guidelines, fire-resistant structures) and irrigated ‘defensible space’ may need to be part of the design.

Here are some non-plant elements to consider as part of the ‘bones’ of the site:

• Create a visual hierarchy (dominant to subordinate elements) within the overall design. Avoid a jumbled mish-mash “one of everything” look. Instead, use both variation and repetition with scale, texture, color, rhythm and massing. For example, when using different species, repetition of color can help create a visual sense of unity. You may want to screen, frame or borrow certain views. Divide the space or leave it open. During the design process, imagine how your experience would change as you move through the space.
• Terraforming and drainage: If the soil has poor drainage, consider mounds, berms or raised planters or choose plants that are adapted. Capture runoff with rain gardens in low spots or seasonal creek-beds. Slopes can be terraced for easier access, erosion control and visual interest.
• Consider openings for paths, sitting areas, water features, sculpture, bare soil for native bees, gravel or mulch, or animal feeders. Be sure to plan enough open space for plants to grow to full size.
• Harmonize hardscape materials with existing building materials, styles and soil colors. Consider using local stone if available. Paint colors may complement or offset adjacent vegetation.
• Include hardscape elements to visually offset vegetation, divide space and add interest: Boulders, walls, steps, a pergola/arbor, swing, furniture, footbridge, raised planters, a water feature, patio, and potted plants are examples. Try to avoid a cluttered look by keeping it simple and maintaining a visual hierarchy.
• Lighting: Again, keep it simple. Path and step safety are priorities. Patio lighting for entertaining is also useful. Use low voltage, solar, LED, or lanterns and avoid glare at eye level.
• Hydrozones: If using automatic irrigation, lay out irrigation valves so that all of the plants on one valve (station) have the same water requirements. This is easier if they are all from the same plant community. Or just drag the hose until the plants are established.

Vegetation elements to consider:

• Group similar plant communities that are locally adapted: This has both practical and aesthetic advantages. Plants from the same plant community have similar soil and water needs and similar mycorrhizal associations. Microclimates to
  accommodate riparian, chaparral or other plant communities can be created. Visually, these related plants naturally appear to belong together and reflect an authentic ‘sense of place’. For best success, pick plants that do well in the type of soil, drainage, sun/shade and water existing on the site and start with a weed-free site before planting.
• Structural “bones”: Woody evergreen foundation shrubs and trees or an interesting deciduous tree will create a year-round visual framework. You may want varied heights, with an overstory, and understory, or you may prefer all groundcovers, depending on the desired effect. Either way, lead the eye with a ‘visual hierarchy’ of focus, using massing or repetition, color and leaf texture. Avoid a jumbled ‘one of everything’ look. Concentrate interest near the entrance or wherever you want the eye to end up. Once the basic framework is set up, fill in with annuals, herbaceous perennials, bulbs or other plants that need to be cut back for part of the year.
• Texture: Leaves can appear coarse, medium or fine-textured. Create gradual transitions, then add variety with accents or trees. Fine textures may appear farther away while coarse textures may appear closer. This illusion can be manipulated to make a space look larger or smaller.
• Accents and contrast: Examples of accent plants could be a large plant or tree, bright color, sculptural shape (e.g. agave), textural contrast, and bold grasses. Placing a light plant against a dark background or combining gray foliage with green foliage also creates contrast.
• For seasonal interest, include flowers that bloom in different seasons, berries, seedpods, leaf colors, and the outlines of deciduous trees & shrubs.
• Pay attention to leaf and bark colors, not just flower colors: dark green, yellow-green, gray-green, silver gray, bronze and fall colors. Transition the colors and then add accents (e.g. gray). Some shrubs can be pruned up to showed off handsome bark.
• Create rhythm with repetition and massing, This does not mean planting a mono-culture, but planting a row of trees or massing shrubs in odd-numbered groups such as 3, 5, 7 etc. is often pleasing.