Watering Strategies from South Bay Botanic Garden

by Susan Krzywicki

Eddie Munguia, Horticultural Lab Technician South Bay Botanic Garden

Eddie Munguia, Horticultural Lab Technician South Bay Botanic Garden – Photo by Susan Krzywicki

After so much debate about how to water native plant gardens, you’d think it had all been said. Let me add some tips and techniques from Eddie Munguia, who is the Horticultural Lab Technician at the South Bay Botanic Garden, located on the campus of Southwestern College in Chula Vista. Eddie installed a native garden over four years ago and one of the key objectives of the botanic garden is to do just this sort of closely observed research and analysis.

Split Cycle Watering – preventing root zone waterlogging
Last July, after attending a professional workshop, Eddie decided to experiment with split cycling – taking the duration of watering proposed, and dividing it into two segments with a two hour gap in between. For example, instead of running a sprinkler zone for 10 minutes, he runs the zone for 5 minutes, in the early morning hours. This allows for absorption by the soil, while avoiding swamping the plant, which can lead to disease and plant death. Eddie has decided that his clear mandate is to “imitate rainfall” by providing supplemental irrigation that looks more like our natural pattern: gentle, sparse summer rains, not heavy storms. During Santa Anas, he recommends 2 minute spritz to cool the plants off. If the plant is suffering from summer stress, he doesn’t dump a lot of water on it, he just refreshes it.

The garden, which is well over 5,000 square feet, is mostly Diablo clay with native hybrid species originating in San Diego county and the Channel Islands.

A view of South Bay Botanic Garden

A view of South Bay Botanic Garden – Photo by Susan Krzywicki

Results: longer bloom times, good growth
Within two weeks of implementing this strategy in July, everything was flourishing. Coast sunflower (Encelia californica) now blooms two months longer. Bladderpod (Isomeris arborea) now produces flower for him all year round. Showy penstemon (Penstemon spectabilis) is blooming later in the year. Bush poppy (Dendromecon rigida) species doubled in size. The garden stay a little greener into summer. And Eddie even observed a third flowering cycle for San Miguel Island buckwheat (Eriogonum grande rubescens).

Advice: Experiment and adjust
Eddie says, “Don’t be afraid to experiment with your watering cycles. As long as you are not bogging them down, or the root zone is getting drenched, they will do OK.” He says he got lucky on the first try with his split-cycle low-impact changes. So, if you follow his method, note garden changes over at least a month, then adjust again.

Would you consider this for your native garden? Please let us know your thoughts, and, if you try this method, please do keep us up-to-date with your progress and observations.

This article was first published in the San Diego Horticultural Society October 2016 newsletter.

Susan Krzywicki is a native plant landscape designer in San Diego. She has been the first Horticulture Program Director for the California Native Plant Society, as well as chair of the San Diego Surfrider Foundation Ocean Friendly Gardens Committee, and is on the Port of San Diego BCDC for the Chula Vista Bayfront.

A Wild Cyclamen from California

by Carol Bornstein

This article, first published in the January/February 2011 issue of The American Gardener, is reprinted with permission of the American Horticultural Society.

Since leaving Michigan almost 30 years ago, I have made the acquaintance of many fine California native plants. My list of favorites keeps changing but Cleveland’s shooting star (Dodecatheon clevelandii, now called Primula clevelandii) is always among them.

dylan-neubauer-dodecatheon-clevelandii-ssp-insulare

Primula clevelandii ssp. insulare – Photo by Dylan Neubauer

SHOOTING STARS
California is home to eight of the dozen or so species in the genus Dodecatheon, which is predominantly native to western North America. The lone representative of the eastern United States is eastern shooting star (D. meadia).

The genus possesses a list of evocative common names: American cowslip, rooster combs, bird-bills, mosquito-bills, mad violets, sailor caps, prairie pointers, and wild cyclamen. The last is particularly apt, because cyclamen are the Asian and European relatives of Dodecatheon.

In California, shooting stars comprise two basic categories: high-elevation species that bloom in the late spring or summer and occur in moist habitats, and lowland species that bloom in late winter or spring and grow in the winter-wet, summer-dry Mediterranean climate regions of the state. They share easily recognizable flowers, whose slightly askew, reflexed petals are indeed reminiscent of cyclamen. Borne in loose umbels, the nodding white to magenta flowers seem to dance atop leafless stalks, stealing the show from the rather plain basal foliage.

Cleveland’s shooting star (D. clevelandii, USDA Zones 6-9, AHS Zones 9-5) is one of the most appealing members of the genus. Found throughout much of California’s Mediterranean core, this clove-scented perennial grows wild on grassy slopes and flaps in chaparral, foothill woodland, and valley grassland communities from central California south into Baja California, Mexico. The most commonly cultivated form, D. clevelandii ssp. insulare, is found in southern California and the offshore Channel Islands.

Emerging in fall, shortly after the rainy season begins, the plant’s light green, somewhat succulent leaves signal the end of its summer dormancy period.

Soon thereafter, the flower stalk elongates, reaching eight to 16 inches tall. Once the buds open, the upswept petals of lilac, rose, magenta, or white appear poised for flight. Later, the ripening seeds within the tan seed capsules rattle in the slightest breeze.

GROWING REQUIREMENTS
Although widespread in nature, Cleveland’s shooting star isn’t as easy to find in commerce. Yet gardeners who successfully track down seeds or plants will be amply rewarded if they follow a few simple guidelines. Place them in a sunny or partly shaded location and keep them well watered from autumn through spring. Then allow them to dry out completely in summer, otherwise their delicate, fleshy roots will rot. The succulent leaves and roots attract snails, slugs, and gophers, so protect the plants from these pests. Seeds germinate fairly easily and plants reach flowering size in about three years.

There are many ways to appreciate shooting stars in the garden. Growing them in containers is the most reliable method, whether nestled into established plantings while in flower and whisked away as the foliage yellows, or combined with other compatible plants in a trough garden. Rock gardeners can tuck a few among bulbs, succulents, and other diminutive companions.

For a captivating effect, plant drifts in a grassy meadow or beneath the dappled shade of trees or tall shrubs such as redbuds or manzanitas (Arctostaphylos ssp.). Be sure to retain the showy, dried inflorescences long enough to release the next generation of shooting star seeds.

Carol Bornstein is Director of the Nature Gardens at the Natural History Museum of Los Angeles County. She co-authored California Native Plants for the Garden and Reimagining the California Lawn. For 28 years, she was a horticulturist at the Santa Barbara Botanic Garden.