Plants: Nitrogen Fixers for Temperate Climate Permaculture Forest Gardens

Nitrogen is a vital nutrient for plants and plant growth.  Nitrogen fixing plants are also a vital component of rebuilding soil fertility with permaculture.  These plants comprise a large part of the forest garden.


As a nitrogen fixing plant grows, it creates a symbiotic relationship with bacteria.  It is an involved process, but the bottom line is that excess nitrogen is built up in the plants tissues.  When leaves fall, roots die, or gardeners prune back leaves (and drop them on the ground to decompose) the excess nitrogen is released back into the soil.  This excess nitrogen is picked up by the other plants in the area and utilized for their own growth.


When forest gardening and rebuilding soil fertility, we can surround our one producer plant (a fruit or nut tree, bush, or vine) with many nitrogen fixing plants.  As our producer grows, we can chop leaves from the nitrogen fixing plants and mulch our producer.  This feeds our producer from the top.  Also, as we cut leaves, some of the nitrogen fixing plant's roots die back as well.  This fertilizes from underground.  And all that extra organic matter continues to build the water retaining capabilities of the soil, provides food for worms, and hiding places for beneficial insects, etc.  There are just so many benefits from this.


Here is a more in-depth discussion from Wikipedia about the process:

"Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and amino acids for proteins. Nitrogen fixation also refers to other biological conversions of nitrogen, such as its conversion to nitrogen dioxide."  (click here for the full aricle if you are really interested)

Following is a list of plants that I assembled and will continue to work on as I obtain more information.  All are nitrogen fixers that are compatible with temperate climate permaculture.  Plants are listed alphabetically by scientific name.  There are a few plants with the same common name.  Sometimes I came across multiple listings for Zones for an specific plant.  I tried to list the most common and/or reliable zone information.  Also, if only one zone is listed, then the plants are hardy to that USDA Zone.

Nitrogen Fixing Plants for Temperate Climate Permaculture

TALL TREES for Temperate Climate Permaculture
(50 feet or taller)

1. Gray Alder, Alnus incana, Zone 2-6
2. Black Locust,  Robnia pseudoacacia, Zone 3b
3. Japanese Pagoda Tree, Sophora japonica, Zone 4-8

SMALL TREES AND MEDIUM-LARGE SHRUBS for Temperate Climate Permaculture
(3-50 feet tall)

1. Prarie Acacia, Acacia angustissima, Zone 7-10
2. Silk Tree or Mimosa, Albizzia julibrisin, Zone 6
3. Alder,Italian, Alnus cordata, Zone 6
4. Alder, Speckled, Alnus rugosa, Zone 2-6
5. Alder, Smooth, Alnus serrulata, Zone 5-8
6. False Indigo, Amorpha fruticosa, Zone 3
7. Siberian Pea Shrub, Caragana arborescens, Zone 2-7
8. Russian Pea Shrub, Caragana frutex, Zone 2-7
9. Pygmy Pea Shrub, Caragana pygmaea, Zone 3-7
10. Mountain Mahogany, Cercocarpus montanus, Zone 6
11. Bladder Senna, Colutea arborescens, Zone 5-7
12. Russian Olive, Elaeagnus angustifolia, Zone 2
13. Silverberry, Elaeagnus commutata, Zone 2-6
14. Goumi, Elaeagnus multiflora, Zone 5-8
15. Autumn Olive, Elaeagnus umbellata, Zone 3
16. Elaeagnus, Elaeagnus x ebbingei, Zone 6
17. Kentucky Coffee Tree, Gymnocladus dioica, Zone 4
18. Sea Buckthorn, Hippophae rhamnoides, Zone 3-7
19. Golden-chain Tree, Laburnum anagyroides, Zone 5
20. Bush Clover, Lespedeza bicolor, Zone 4-7
21. Bush Clover, Lespedza thunbergii, Zone 5
22. Amur Maackia, Maackia amurensis, Zone 3-7
23. Southern Bayberry, Myrica cerifera, Zone 6b-9
24. Northern Bayberry, Myrica pensylvanica, Zone 2-7
25. Honeypod Mesquite, Prosopis glandulosa, Zone 7
26. Bristly Locust, Robina hispida, Zone 4-8
27. Clammy Locust, Robina viscosa, Zone 5-8
28. Buffaloberry, Shepherdia argentea, Zone 2
29. Canadian Buffaloberry, Shepherdia canadensis, Zone 2
30. Spanish Broom, Spartium junceum, Zone 8

HERBACEOUS PLANTS AND SMALL SHRUBS for Temperate Climate Permaculture
(Typically under 3 feet)

1. Dwarf Prarie Acacia, Acacia angustissima hirta, Zone 7-10
2. Leadplant, Amorpha canescens, Zone 3
3. Fragrant False Indigo, Amorpha nana, Zone 3-6
4. Canadian Milkvetch, Astragalus canadensis, Zone 3-8
5. Groundplum Milkvetch, Astragalus crassicarpus, Zone 3-8
6. Milkvetch, Astragalus glycyphyllos, Zone 4-8
7. Huang-Qi, Astragalus membranaceous, Zone 5
8. Painted milkvetch, Astragalus pictus-filifolius, Zone 5
9. Wild Blue Indigo, Baptisia australis, Zone 4-8
10. Wild Yellow Indigo, Baptisia tinctoria, Zone 4-9
11. New Jersey Tea, Ceanothus americanus, Zone 3b
12. Mahala Mat, Ceanothus prostatus, Zone 7-10
13. Sweetfern, Comptonia peregrina, Zone 2-6
14. Prostate Broom, Cytisus decumbens, Zone 6-8
15. Showy Tick Trefoil, Desmodium canadense, Zone 3-6
16. Pointed-Leaved Tick Trefoil, Desmodium glutinosum, Zone 3-9
17. Mountain Avens, Dryas octopetala, Zone 2-4
18. Silky-Leaf Woodowaxen, Genista pilosa, Zone 6-8
19. Trailing Silky-Leaf Woodwaxen, Genista pilosa procumbens, Zone 6-8
20. Arrow Broom, Genista sagittalis, Zone 3-8
21. Dryer's Greenwood, Genista tinctoria, Zone 4-7
22. American Licorice, Glycyrrhiza lepidota, Zone 3-8
23. European Licorice, Glycyrrhiza glabra, Zone 6/7
24. Chinese Licorice, Glycyrrhiza uralensis, Zone 5-9
25. Sweet Vetch, Hedysarum boreale, Zone 3
26. Sea Buckthorn "Dorana Dwarf", Hippophae rhamnoides cv., Zone 3-7
27. Chinese Indigo, Indigofera decora, Zone 5
28. Round-Headed Bush Clover, Lespedeza capitata, Zone 4-8
29. Prostate Bird's-Foot Trefoil 'Plena', Lotus corniculatus cv., Zone 5
30. Lupine, Lupinus species., Zone 3-9
31. Alfalfa, Medicago sativa, Zone 3
32. Sweet Gale, Myrica gale, Zone 1-6
33. Breadroot (Prarie Turnip), Psoralea esculenta, Zone 3-7
34. Two-Flowered Pencil Flower, Stylosanthes biflora, Zone 5
35. Carolina Bush Pea, Thermopsis villosa, Zone 5-8
36. Red Clover, Trifolium pratense, Zone 3
37. White Clover, Trifolium repens, Zone 4

VINES AND CLIMBERS for Temperate Climate Permaculture

1. Hog Peanut, Amphicarpeaea bracteata, Zone 3-9
2. Groundnut, Apios americana, Zone 3
3. Fortune's Groundnut, Apios fortunei, Zone ?
4. Price's Groundnut, Apios priceana, Zone 6
5. Butterfly Pea, Clitoria mariana, Zone 6-9
6. Beach Pea, Lathyrus japonicus maritima, Zone 3b-7
7. Perenial (Everlasting) Pea, Lathyrus latifolius, Zone 4-9
8. Bitter Vetch, Lathyrus linifolius var. montanus, Zone 6b
9. Earth-Nut Pea, Lathyrus tuberosus, Zone 6b
10. Scarlet Runner Bean, Phaseolus coccineus, Zone 9 or Annual plant
11. Wild Bean, Phaseolus polystachios, Zone 6-10
12. Pea, Pisum sativum, Annual plant
13. Wild Bean, Stophostyles umbellata, Zone 6-9
14. American Vetch, Vicia americana, Zone 3-7
15. Wood Vetch, Vicia caroliniana, Zone 3-9
16. Tufted Vetch, Vicia cracca, Zone 6
17. Japanese Wisteria, Wisteria floribunda, Zone 4-9
18. American Wisteria, Wisteria frutescens, Zone 5
19. Kentucky Wisteria, Wisteria macrostachya, Zone 5-9

Most information for this page from Gaia's Garden and Edible Forest Gardens.