A Selection of Manzanitas

Large Shrubs or Trees

Arctostaphylos glauca, bigberry manzanita

A.manzanita, Parry manzanita

Medium Shrubs

A. bakeri ‘Louis Edmunds’, Louis Edmunds manzanita

A. ‘Howard McMinn’, Howard McMinn manzanita

A. ‘John Dourley’, John Dourley manzanita

A. ‘Sentinel’, Sentinel manzanita

A. ‘Sunset’, Sunset manzanita

A. pajaroensis ‘Paradise’, Paradise manzanita

Low Shrubs and Groundcovers

A. ‘Pacific Mist’, Pacific Mist manzanita

A. edmundsii, Edmunds manzanita

A. edmundsii ‘Carmel Sur’, Carmel Sur manzanita

A. pumila, sandmat manzanita

Planting on Slopes for Erosion Control

  1. Although plants do retain topsoil, they cannot be counted on to provide structural support to unstable slopes. Unstable slopes may require significant grading or slope modification by a qualified engineer.
  2. Create small terraces to hold water and soil while plants are becoming established and root systems are developing. Place new plants toward the outside of the slope so that debris from the slope does not collect around the plant crown or stem resulting in crown rot.
  3. Plant selection:
  • Cover slope with both rapid-growing short-lived, and slow-growing long-lived plants.
  • Select plants with extensive, wide spreading root systems.
  • Use a variety of plants. Large shrubs with extensive root systems should be given adequate space to develop. Smaller plants and low groundcovers can be placed between larger plants to further reduce soil erosion. Include plants with taps roots and those with fibrous roots.
  1. Supplemental irrigation is usually needed during the establishment period. The watering practice should assist deep rooting - water in short periods with intervals between watering to facilitate percolation and reduce runoff. The time periods for and between the application of water will vary depending on the type, texture and composition of the soil. Careful observation will allow you to establish effective watering schedules. Remember that upper slope areas will dry more quickly, while lower slope sections may become over-saturated.
  2. Jute netting tacked down on exposed slopes will help reduce erosion and keep plants in place as their roots develop. Mulch is not much help since much of it washes off during rains.
  3. If you have fire concerns, be sure to consult other references for plant selection and proper horticultural practices aimed at reducing fire risk.

 

Short list of easy-to-grow California native plants for use on slopes*

* For fire concerns, consult your fire department and plant lists specifically addressing fire safety issues.

Achillea millefolium (common yarrow)

Adenostoma fasciculatum (dwarf chamise)

Arctostaphylos edmundsii (big sur manzanita)

Arctostaphylos hookeri (Hooker manzanita)

Atriplex lentiformis brewerii (quail brush)

Baccharis pilularis (coyote brush)

Baccharis pilularis ‘Pigeon Point’ (dwarf coyote brush)

Baccharis pilularis ‘Twin Peaks 2’ (dwarf coyote brush)

Ceanothus spp. (wild lilac)

Encelia californica (coast sunflower)

Eriogonum fasciculatum (California buckwheat)

Heteromeles arbutifolia (toyon)

Iva hayesiana (San Diego marsh-elder)

Keckiella antirhinoides (yellow penstemon)

Malosma laurina (laurel sumac)

Rhus ovata (sugar bush)

Rhus integrifolia (lemonadeberry)

Salvia leucophylla (purple sage)

Salvia leucophylla ‘Pt. Sal Spreader’ (purple sage)

Salvia mellifera (black sage)

Salvia mellifera ‘Terra Seca’ (dwarf black sage)

Yucca whipplei (chaparral yucca)

Native Plants for Clay and Heavy Soils

Amending clay soil can be a difficult process. If it is not done properly, it can make growing conditions worse. Too little sand added to clay can result in a decrease in permeability (clay plus sand equals concrete). Sometimes amending heavy soil can lead to difficult drainage problems at the interface of the amended soil and the native soil. Water can collect in this area further aggravating poor drainage.

Because of this we recommend using plants that are adapted to your native soil and being especially careful with your gardening practices. Heavy soils often have poor aeration and a high water-holding capacity. For success with these conditions, water carefully. Watering too often will lead to root rot problems. Water well and slowly, allowing the water to fully permeate the soil without running off. Be sure to allow the soil to dry, though it is best not to let it become bone dry since this condition will pull water from the plants and can result in crusting and cracking of the soil.

The following is a list of native plants that can grow in soils with less than excellent drainage.  

Plant Names

Common Names

Chlorogalum pomeridianum

Coreopsis maritima

Dichelostemma pulchellum

Epilobium canum

Erigeron sp.

Erigeron glaucus

Eriophyllum confertiflorum

Eriophyllum nevinii 'Canyon Silver'

Fragaria chiloensis

Grindelia robusta

Heuchera maxima

Heuchera micrantha 'Martha Roderick'

Iris douglasiana

Iris douglasiana 'Canyon Snow'

Iris longipetala

Juncus patens

Keckiella cordifolia

Lilium humboldtii

Mimulus aurantiacus

Mimulus cardinalis

Nolina parryi

Oenothera hookeri

Oxalis oregana

Penstemon centranthifolius

Penstemon heterophyllus

Penstemon spectabilis

Polypodium californicum

Potentilla glandulosa

Ranunculus californicus

Salvia spathacea

Satureja douglasii

Sisyrinchium bellum

Solidago californica

Tanacetum camphoratum

Tellima grandiflora

Thalictrum fendleri var. polycarpum

Triteleia laxa

Woodwardia fimbriata

Yucca whipplei

 

Woody Shrubs and Trees

Acer macrophyllum

Alnus rhombifolia

Berberis fremontii

Calocedrus decurrens

Cercis occidentalis

Cercocarpus betuloides

Chamaecyparis lawsoniana

Chilopsis linearis

Cupressocyparis leylandii

Cupressus forbesii

Forestiera pubescens

Fraxinus dipetala

Isomeris arborea

Juniperus californica

Lavatera assurgentiflora

Lithocarpus densiflorus

Lonicera interrupta

Lonicera involucrata

Mahonia 'Golden Abundance'

Mahonia 'Skylark'

Mahonia aquifolium

Mahonia nevinii

Mahonia pinnata

Mahonia repens

Pinus attenuata

Pinus coulteri

Pinus sabiniana

Pinus torreyana

Potentilla fruticosa

Quercus agrifolia

Quercus chrysolepis

Quercus lobata

Rhamnus californica

Rosa californica

Washingtonia filifera

soap plant

sea dahlia

blue dicks

California fuchsia

fleabane

seaside daisy

golden yarrow

Canyon Silver island snowflake

beach strawberry

gum plant

island alum root

Martha Roderick alum root

Douglas iris

Canyon Snow Douglas iris

coast iris

wire grass

heartleaf keckiella

Humboldt lily

bush monkeyflower

scarlet monkeyflower

Parry beargrass

Hooker’s evening primrose

redwood sorrel

scarlet bugler

foothill penstemon

showy penstemon

California polypody

sticky cinquefoil

buttercup

hummingbird sage

yerba buena

blue-eyed grass

California goldenrod

dune tansy

Forest Frost fringe cup

meadow rue

brodiaea

giant chain fern

chaparral yucca

 

 

big-leaf maple

white alder

Fremont barberry

incense cedar

western redbud

birch-leaf mountain-mahogany

Lawson cypress

desert willow

Leyland cypress

Tecate cypress

desert olive

California ash

bladderpod

California juniper

tree mallow

cutleaf tanbark oak

chaparral honeysuckle

twinberry

Golden Abundance barberry (RSABG Introduction)

Skylark barberry

Oregon grape

Nevin’s barberry

creeping barberry

creeping barberry

knobcone pine

Coulter pine

foothill pine

Torrey pine

shrubby cinquefoil

coast live oak

canyon live oak

valley oak

coffeeberry

California rose

California fan palm  

Soil Amendments

The best horticultural practice when transplanting trees or shrubs, native or non-native, is to use existing soil as backfill for the planting hole.

Roots tend to stay in planting holes with amended soil rather than growing out of the hole to form an extensive and healthy root system. In fact they can encircle the planting hole, just as they do when they outgrow a container, further hindering root establishment.

Amending the soil in the planting hole can result in poor water mobility between the planting hole and the surrounding native soil. During winter when there is rain, water in the planting hole will not migrate out to the surrounding soil, resulting in excessive moisture around the roots and crown. In the summer, the plant quickly uses up the water in the planting hole, while at the same time the surrounding soil is drawing this water away from the hole. The plant will need frequent irrigation, and may rot from excessive heat and moisture.

Organic amendments decompose. If they comprise much of the soil in the planting hole, the plant can sink or pockets can form, further exacerbating drainage problems near the plant.

Rather than modifying your garden, select plants that are adapted to your conditions. Native plants clearly are well-adapted to their local setting. Gardens, though, represent a great disturbance to the natural environment. Select native plants that accept disturbance, while you work towards creating a more stable system. Forego soil amendments, fertilizers, irrigation, and physical disturbance to the soil. Not only will your native plants appreciate this, it is far easier on your back and wallet!