Tom Karwin, On Gardening | Locating garden plants – Santa Cruz Sentinel

Take care of your garden

We are now continuing the seasonal focus on garden development, taking into account the timely installation of new plants at the beginning of the rainy season (after a long wait).

The basics of garden development are plant selection and plant placement. Let’s focus on the placement.


An overview perspective concerns the distance. Some gardeners prefer spaces between plants so that each plant can develop its unique properties. This approach can be particularly useful for a collection of varieties within a single genus, e.g. A rose bed, can be effective for showing differences between plants. The spaces between plants can be filled with mulch or a low ground cover to limit weed growth.

Alternatively, aesthetically pleasing design and effective weed control can be provided by providing just enough space for each plant to reach its mature latitude. Tight spaces require more plants per square foot than open spaces. It also requires learning the final size of each plant and patiently waiting for it to grow in order to achieve the intended design.

An open spacing error could occur when the gardener tries to contain costs by “filling” an area with a limited number of plants that are not growing large enough to produce a good effect. A better approach to planting seeds or beginnings of annual flowering plants to complement smaller perennials or shrubs as they grow.

Natural grouping

Another important aspect of plant placement concerns the relationships between plants.

The natural grouping of plants includes colonies and companions. Plants form colonies by multiplying by falling seeds; Spreading of runners; Creating offsets; and increasing bulbs, rhizomes, tubers, etc. Plant colonies are usually closely grouped close to the parents, but when seeds are dispersed by wind, birds, or animals, the results can be widespread or isolated plants.

Companion plants in nature are simply those that develop close together in a particular habitat, which can be forest, forest, grassland, or desert. The larger concept, a biotic community, is a group of plants and other organisms that live together and interact with one another within an environment or habitat. To put it in a nutshell, the even bigger concept that encompasses the physical environment is an ecosystem.

The ecological design of your garden (a topic too extensive for this column) includes considering wildlife as well as your plants.

The gardener could closely group plants according to natural guidelines by grouping multiple specimens of a selected plant. The usual practice is to create groups with an odd number of plants: three, five, seven, etc.

To simulate naturally occurring large plant spacing, the gardener could install drifts or replicas of a selected plant. Repeated placements should be close enough to one another to suggest the spread of the plants through nature.

Following nature’s accompanying plant model could require the gardener to study the chosen habitat, as plant hunters do, as we can observe in a few webinars. (Last week’s webinar with Kelly Griffins “Oaxaca Meanderings in Search of Succulents” was an example of this.)

A simpler approach is to delve into the literature of the chosen habitat. One strategy available for California native plants is to visit the California Native Plant Society website:, which provides the Calscape Garden Planner to find “Plants Unique to Your Zip Code and Design Ideas for a Range of Landscape Styles.” to find. Remember that habitats contain microclimates, so all plants growing within a particular zip code are not necessarily natural companions.

Aesthetic grouping

Rather than following nature’s guidelines, the gardener could place plants in such a way that they offer aesthetic pleasure, or at least interest. The main variables include plant size, leaf shape and color, and flower color.

Plant size groupings generally follow the basic rule of “larger plants in the back”, but openly structured plants, e.g. B. in the foreground. To learn more about such a grouping, visit

When grouping plants by leaf shape, it is common to include contrasting shapes or colors. While grouping plants with similar leaf shapes or colors may be pleasant, it is difficult to imagine three red-leaved trees in a group. However, it can be attractive to combine evergreen dwarf shrubs with similar needles but different shades of green.

Plant groupings based on flower color could highlight a single color, e.g. Sissinghurst Castle’s famous white garden, or use the color wheel to create analog, complementary, triadic or tetradic color combinations.

Many plants can be grouped aesthetically. The success of the design depends on the viewer, so pursue your vision. While we never say never and a bold design might be a worthy experiment, grouping plants from different habitats might disappoint. For example, the combination of a rose and a cactus may not win a design competition.

Enrich your garden days

A good project in your garden would be evaluating current plant locations or planning new groups in a developing garden. If you find that some existing plants could be grouped differently for better effect, the current time of year is a good time to rearrange plants or add plants to create an appealing display.

Enjoy your garden!

Tom Karwin is past President of Friends of the UC Santa Cruz Arboretum, Monterey Bay Area Cactus & Succulent Society, and Monterey Bay Iris Society, and a Lifetime UC Master Gardener (Certified 1999-2009). Today he is a board member and garden coach of the Santa Cruz Hostel Society. To view photos from his garden daily, To search an archive of previous On Gardening columns, visit Contact him with comments or questions at [email protected]

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