NOTE: Asterisk indicates plant is combustible and may need extra maintenance.
KEYS TO FLOWER COLOR: B = Blue; V = Violet/Purple; R = Red; 0 = Orange; G = Green; W = White; P = Pink; Y = Yellow
Groundcovers (for surface soil retention)
- *Achillea millefolium, Yarrow P/R/W - full sun or part shade; spreads
- Baccharis pilularis ‘Twin Peaks' or ‘Pigeon Point', Dwarf Coyote Brush W
- Ceanothus griseus horizontalis ‘Yankee Point' B
- Grasses with tough fibrous root systems (many choices)
- Mimulus spp., Monkey Flower O/P/R/Y
- Salvia spp., Groundcover Sage Varieties such as ‘Gracias,' ‘Pt. Sal,' ‘Bees Bliss'
- Epilobium canum and E. canum latifolia, California Fuchsia P/R/W (white form requires some shade) Small Shrubs (for soil retention and limited hillside stabilization)
- *Artemisia californica, Coastal Sagebrush G/Y - aromatic, super-tough plant for dry spots
- Brickellia grandiflora, Brickell Bush W - easy to grow and tough; good for partially shaded dry spot
- Encelia californica, California Bush Sunflower Y - fast-growing and easy; reseeds; seeds appeal to birds
- *Eriogonum spp., Buckwheat P/W - especially E. fasciculatum, California Buckwheat
- Fallugia paradoxa, Apache Plume W/Y - tough plant with lovely tufted seedheads
- Isocoma menziesii, Coast Goldenbush Y - cheerful fall bloomer
- Isomeris arborea, Bladderpod Y -bright yellow flowers attract hummers and bumblebees; interesting seed pods
- Iva hayesiana, San Diego Marsh Elder - crisp green color, soft texture; spreads, takes sun or shade
- Romneya coulteri, Matilija Poppy W/Y - tough root system spreads by rhizomes
- Salvia spp., Sages B/P/R/V/W - shrubs such as Black and White Sages, Cleveland Sage, San Miguel Mtn. Sage
- Trichostema lanatum, Wooly Blue Curls B/V - likes a dry sunny spot with excellent drainage
- Yucca whipplei, Our Lord's Candle W
Large Shrubs And Trees (for hillside stabilization)
- *Adenostoma fasciculatum, Chamise W - tough-as-nails, with striking white flower clusters in spring
- Aesculus californica, California Buckeye W - one of the most ornamental native shrubs/trees
- Arctostaphylos spp., Manzanita P/W - very deep root system; many stump-sprout after fire
- Ceanothus spp., California Lilac B/V/W - especially local species; hybrids best with a little afternoon shade
- Cephalanthus occidentalis, Button Willow W - ornamental ball-shaped flowers; deciduous; likes water
- Heteromeles arbutifolia, Toyon W - excellent for screen or bird habitat; adaptable to wet or dry, sun or shade
- Juglans californica, Southern California Walnut - excellent small- to medium-sized shade tree; edible nuts
- Rhus spp.: *Laurel Sumac, Lemonadeberry, Sugar Bush P/W -- drought-resistant, aromatic, attaining large size
- *Pinus coulteri, Coulter Pine; at higher elevations: P. jeffreyi, Jeffrey Pine or P. ponderosa, Ponderosa Pine
- Quercus spp. (Oak) such as Q. agrifolia, Coast Live Oak; Q. dumosa, Scrub Oak; Q. wislizenii, Interior Live Oak
- Sambucus mexicana, Elderberry W/Y - pretty flower clusters and berries; takes moisture or drought Shrubs And Trees For Erosion Control In Dry Or Moist Shade
- Alnus spp., Alder - moisture to get established
- Brickellia grandiflora, Brickell Bush W - dry
- Calycanthus occidentalis, Spice Bush R - dry or moist
- Cercis occidentalis, Western Redbud P - dry
- Cornus spp., Dogwood W - moist
- Euonymus occidentalis, Burning Bush P - moist
- Iva hayesiana, San Diego Marsh Elder - dry or moist
- Quercus chrysolepis, Canyon Live Oak - dry or moist
- Ribes spp., Currants and Gooseberries - dry or moist
- Rosa californica, Wild Rose P - moist; tolerates dry
- Salix spp., Willow - moist or wet
- Spiraea douglasii, Spiraea P - moist
- Symphoricarpos mollis, Snowberry P - dry or moist
- Umbellularia californica, CA Laurel W - dry or moist
Notes: The listed species of yarrow, sagebrush, buckwheat and grasses have fine foliage or flowers which, when dry, are easily ignitable. These species should not be planted unless you can commit to extra maintenance - regularly remove spent flowers and any dead material, train plant as a low groundcover, and keep a clear buffer zone around the patch.
Chamise is on most fire-prevention agencies' lists of fire-hazardous plants, so it is best to avoid planting it within 200' of any structure. If it is already growing in your yard and serving a good erosion-control function, just maintain it assiduously free of any dead or dying material and leaf litter, well-pruned into a light, open form, or trained low as a groundcover, and isolated from other potential fuels.
The same advice goes for laurel sumac - if it is thriving on your hillside, retain enough of it to keep serving your erosion control needs, but maintain it "lean, clean and green", as described above for chamise. If you are replacing a laurel sumac bush, try one of the other "Rhus" species listed - lemonadeberry or sugarbush, which are less resinous than the sumac.
Pines are also on most lists of fire-prone trees, and they are not well-adapted to Monrovia's warmth and dryness. Many cities and individuals are currently spending large amounts of money to remove pines that have become overgrown, so it is not recommended that you plant a pine. To maintain an existing pine, keep the pine needles cleaned up and limb the tree up to at least 6' from the ground (but no more than 1/3 of the tree's height) to prevent a fire ladder and prune away any branches that come within 10 feet of a structure.
