When it comes to nitrogen in your soil there are only a few ways to get it. Since nitrogen does not stay put as a mineral in the soil, a gardener has to figure out how to get it out of the air or be forced to go to the store to get a bag of it. The great thing about this is that it is easy and cheap to entice nitrogen from the air!

Nitrogen Fixers

Of course, if you know much about gardening, you know that I am cheating a bit. It is well known that plants like peas and beans have a relationship with bacteria that colonize their roots and fix nitrogen out of the air. What is lesser know is the shear number of plant that can do this, and some of them are not related to beans at all. Those that are in the bean family are generally called legumes. The others are spread out amongst a number of other families and there doesn’t seem to be much of a pattern for those that live in the temperate zones.

Nature’s Seed has a great collection of nitrogen fixing plants for you. Let’s start by looking at a list of the nitrogen fixing plants from our wildflower collection:

• Arizona Lupine, Lupinus arizonicus, Annual
• Arroyo Lupine, Lupinus succulentus, Annual
• Desert Lupine, Lupinus sparsiflorus, Annual
• Desert Senna, Senna covesii, Perennial
• Miniature Lupine, Lupinus bicolor, Annual
• Mountain Lupine, Lupinus argenteus ssp. rubricaulis, Perennial
• Purple Prairie Clover, Dalea purpurea, Perennial
• Silverleaf Lupine, Lupinus argenteus, Perennial
• Utah Sweetvetch, Hedysarum boreale, Perennial
• Wild Lupine, Lupinus perennis, Perennial

Nitrogen fixing plants are also common in our pasture seed collection. They help provide protein to animals and strengthen other pasture plants by providing nitrogen to the other species nearby:

• Alfalfa, Medicago sativa, Perennial
• Alsike Clover, Trifolium hybridum, Perennial
• Birdsfoot Trefoil, Lotus corniculatus, Perennial
• Cicer Milkvetch, Astragalus cicer, Perennial
• Crimson Clover, Trifolium incarnatum, Annual
• Field Pea, Pisum sativum ssp. arvense, Annual
• Hairy Vetch, Vicia villosa, Annual
• Indian Ricegrass, Achnatherum hymenoides, Perennial
• Red Clover, Trifolium pratense. Perennial
• Sainfoin, Onobrychis viciifolia, Perennial
• White Clover, Trifolium repens, Perennial
• White Sweet Clover, Melilotus alba, Biennial
• Yellow Sweet Clover, Melilotus officinalis, Biennial

Many of our wildflower, pasture, and honeybee blends also contain healthy amounts of nitrogen fixing plants. These blends are a great way to go for those that have either general or specific needs. I recommend you check them out for convenience and versatility. If you are looking for the most nitrogen bang for your buck, alfalfa, hairy vetch, crimson clover, alsike clover, white clover, red clover, sainfoin, yellow sweet clover, and white sweet clover are your best choices as they are all noted for great nitrogen production.

Nitrogen is the most commonly needed nutrient of most plants. With a little bit of thought and planning you can use some of the above plants to improve nitrogen access in your annual and perennial plantings. Keep an eye out in the near future and I will be talking a little more about the specifics of how to design and maintain a nitrogen producing planting.

Manana!