I'd welcome corrections and additions to this list of nitrogen-fixing trees and plants that will grow in coastal California.  Permaculturist Geoff Lawton recommends in his new video on how to create a food forest that we plant nitrogen-fixers between the fruit and nut trees and then "chop and drop" the trimmings around the food trees.  He even recommends planting large trees but keeping them pollarded (radically cut back) so they keep putting out shoots you can use for this purpose.

 

Linda

 

NITROGEN-FIXING PLANTS FOR COASTAL CALIFORNIA

 

In your food forest, plant nitrogen-fixing trees and plants between your fruit and nut trees, pruning them (sometimes severely) in a “chop and drop” fashion to feed your food-bearing trees. The plants in bold below grow easily in Santa Barbara.

 

Acacia

Albizia (Silk Tree, Mimosa). Rapid growth to 40.’ Fluffy pink flowers in summer.

Alder. According to Western Sunset Gardens, Italian Alder and Black Alder will grow in Zone 24 (us).

Alfalfa

Beans

Casuarina equisetifolia (Horsetail Tree). Fast grower to 40-60 feet.

Calliandra (Pink Powder Puff) Native to Bolivia.

Ceanothus. California native. Shrub and groundcover forms.

Clover

Cycads

Erythrina (coral tree) berteroana and poeppigiana

Glircidia

Gorse (Ulex europaeus), a native of Europe, now a serious pest along the coasts of Oregon, Washington and California. Gorse forms impenetrable stands due to its dense, thorny growth.

Gunnera

Inga Edulis (Ice Cream Bean tree) Native to riverbanks of Amazon region, so needs water.  Tropical. To 60’. Used for shade in coffee and cacao plantations.

Lab-lab bean

Leucaena (Golden Ball Lead Tree). Shrub or tree. Native to Texas, northern Mexico. 12-20’

Locust (Robinia) Black Locust, Desert Locust. Fast growing, adapted to hot, dry climate. Clusters of white or pink sweetpea shaped flowers bloom midspring to early summer. Bark, leaves and seeds are poisonous if ingested. Thorny plant.

Lupin, including Lupinus arboreus, native to California

Mesquite

Myrica californica (Pacific Wax Myrtle). Evergreen shrub or tree. Aromatic foliage, plus attractive purplish fruits attractive to birds. Native to California coast.

Peanuts

Peas

Pongamia. Indian beech tree. Deciduous, leguminous, drought-tolerant. Showy, fragrant pink-white flowers. People are experimenting with the seed oil as feedstock for biodiesel. Plant parts are toxic if eaten. Many other uses. Oil is antiseptic.

Russian olive (doesn’t do well here)

Scot's broom (Cytisus scoparius), a widespread “pest” plant of the Pacific coast where it was introduced as an ornamental.

Tagasaste. Small drought-tolerant, evergreen leguminous shrub 12’ – 15.’ Grown in Australia for animal fodder as it provides 23 – 27% protein.

Tamarind. Tropical leguminous tree that yields date-like fruit.

Tipuana Tipu. From South America. 25-40’ tall. Blooms late spring to early summer, apricot to yellow, sweet pea shaped flowers. Dislikes strongly alkaline soil. Flowers best away from ocean influence.

Vetch