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Technical Elements

Replacing Ice Plant

Years ago, Freeway iceplant (Carpobrotus edulis) wastouted as the perfect solution for fire safety. Planted on

hillsides of thousands of homes in San Diego, it hassince crawled off the original site and into neighboringOpen Space parks, endangering unique plants bysmothering them. Iceplant provides little habitat valuecompared to the plant community that it is replacing.Compared to the native shrubs, Iceplant has veryshallow roots that do not hold soil well; closeinspection often reveals gullies underneath the twistedmat of vines. After rain, Iceplant engorges with water,substantially increasing its weight. As a result, Iceplantcan cause the deterioration of steep hillsides byencouraging slumping potentially endangering the

house above.

PROCEDURE:

First, remove the iceplant. Then add native containerplants, leaving the dead iceplant to act as mulch whilethe container plants become established. Keep an eyeout for volunteers of native plants, which may returnonce the iceplant is removed.1. Remove the Iceplant:

Because of its shallow roots, iceplant can be easilypulled, piled up and left to dry out (which will takeseveral months).If erosion on a steep hillside is a concern, iceplant can

be killed in place by spraying with 2% (finalconcentration) of Roundup. Choose a low-wind day.Check the label for precise directions on use. Theactive ingredient, glyphosate, is essentially non-toxic

California Native Plant Society - San Diego Chapter

c/o San Diego Natural History Museum - P.O. Box 121390,San Diego, CA 92112-1390 - gardening@cnpssd.org

Thanks to Carrie Schneider and BruceHanson for their ideas and botanica

knowledge in the preparation of thisbrochure

to humans and other animals its target is an enzymespecific to plants; it does not bioaccumulate and i

breaks down over time. It binds tightly to soil particlesand is therefore unlikely to wash from the site. Roundupwill not kill seeds, but it will kill desirable plants, whichmay be covered while one sprays. It will take severaweeks for sprayed plants to start yellowing. A goodschedule to follow is: treat in the spring or summer, thenplant or sow seed in the late fall.2. Plant container plants

First, decide what plants are appropriate, figure ouwhere to get them, and then plant them.

Plant Choice

First, there may be a viable native seed bank, so keepan eye out for volunteers of native plants, which wilreturn once the shade by the Iceplant is removed. Nextchoose plants based on the habitat type that originallyexisted on your hillside. If possible, find a nearby areawith native vegetation, and study the slopes that havethe orientation as yours (for example, south-facing onorth-facing). The native plants growing there are theones that will be successful on your hillside with theleast maintenance.

The plants in the table below are chosen because theyare easy to grow plants, are distributed widely on

hillsides around San Diego, and are consistent witheasy fire-zone management, because their foliageresists ignition, or they can be pruned easily to reducefire risk. Many other native plants fit these criteria.

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Appropriate Plants

Trees or tree-like shrubsHeteromeles arbutifoliaToyon

Quercus dumosaScrub OakQuercus agrifoliaCoast Live Oak

Quercus engelmanniiEngelmann Oak

Rhus integrifoliaLemonadeberry - use sparingly, plants become quite large.

Broad-leaf shrubs

Ceanothussp. California Lilac

Isomeris arboreaBladderpod

Lonicera subspicataChaparral Honeysuckle

Malosma laurinaLaurel Sumac

Prunus illicifolia ssp. illicifoliaHollyleaf Cherry

Rhamnus californicaCoffeeberry

Rhamnus croceaRedberry

Ribes speciosumFuschia-flowered Gooseberry

Simmondsia chinensisJojoba

Groundcovers

Sisyrinchium bellumBlue-eyed Grass (a perennial bulb that spreads)

Artemisia douglasianaDouglas Sage

Epilobium (formerly Zauschneria) California Fuchsia

Eriogonumspp. Buckwheat

Solidago californicaCalifornia Goldenrod

Iva hayesianaIva

Succulents, Cactus, Yucca

These can be easily propagated without irrigation, and they provide substantial habitat benefits. There are a number of

species - find the one that is native to your area.

Cylindropuntiasp. Cholla species (e.g. Opuntia prolifera)

Cylindropuntiasp. Prickly-pear species (e.g. Opuntia littoralis)

Dudleyasp. Dudleya species (e.g. Dudleya pulverulenta)

Yucca schidigeraMojave Yucca

used with permission of www.laspilitas.com

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