Inoculum for Legumes

Inoculum for Legumes

Choose from 16 different rhizobial inoculum strains including Baptisia, Lupinus and many more. 1 bag will inoculate up to 1 pound of seed. 1/2 tablespoon of inoculum per bag.  

Most legume species harbor beneficial bacteria called rhizobia on their roots. Genus-specific strains of this bacterium called inoculum can aid in the fixation of atmospheric nitrogen and improve long-term health of native plant communities, especially in low fertility soils.

HOW TO USE: Add inoculant to dampened seed and mix thoroughly.
WHEN TO ADD: At time of cold, moist stratification, or if direct seeding, as close to planting time as possible.
SPECIAL CARE: Protect inoculated seed from sunlight or drying winds - cover seed as quickly as possible with soil or mulch.
ALTERNATIVE METHODS: Inoculant can be mixed with potting soil when planting in flats or peat pots; directly in the seed furrows along with seed at time of transplanting; or to potted plants by making a hole with a pencil. Inoculum may also be added to potting mix for container grown plants or into the bottom of a hole when transplanting container grown or bare root seedlings.

9 Questions asked on Inoculum for Legumes

Q Chris DeRhodes • April 5 It is effective to apply inoculum to seedlings that have already sprouted in indoor containers? What about something like an existing Baptisia plant growing outside that was planted in post-construction exposed subsoil of questionable quality?
A Prairie Moon • April 8 Thanks for writing, Chris. The bacteria in the inoculums that we carry for legumes typically are already present in most healthy soils. They do not affect plant germination but do establish symbiotic relationships with developing roots to enhance the formation of nodules that absorb atmospheric nitrogen. Adding inoculum to soils is an effective way to introduce or increase the population of beneficial bacteria.
Q Maggie • June 6 Hello, do you offer inoculum for Thermopsis? Thanks!
A Prairie Moon • June 6 Hi Maggie! We do! It's the same as the Baptisia Inoculum.
Q Pam • August 7 How do you choose the best type of inoculum for your soil? Are certain inoculums better for specific plants or seedlings?
A Prairie Moon • August 11 Hi Pam. You really only need to consider purchasing inoculum if you are ordering Legume species - those in the pea family. This Inoculum order page lists the various legume genus', or you can find them by typing 'legume' in the search bar.

If you have very degraded soil, perhaps all organic matter was stripped off from construction, then you could consider our Mycorrhizal Inoculum for Exposed Subsoil, sold by the lb.

Q Olivia • March 10 Does the inoculum keep well for future seasons? Due to variety of species, I’ll need to buy much more than I can use in one season.
A Prairie Moon • March 11 Hi Olivia, Good question! If kept refrigerated, the inoculum will stay viable for at least a year, probably a bit more.
Q Daniel • August 3 I have a few legume species that I would like to direct seed this fall (Amorpha, Chamaecrista, Lupinus). The soil is not the healthiest and has only been lawn. Would you recommend a separate inoculum for each species, or would one inoculum work for all?
A Prairie Moon • August 4 Hi Daniel, Different genera of legumes tend to make associations with different strains of nitrogen fixing bacteria. In most instances this bacteria will be present in the soil, but if you are worried about the quality of the soil, you should get the three appropriate strains for each genus.
Q Beverly • January 18 I wonder how to store this product when not in use, and how long, if properly stored, this product will last. Is it useful only for a single growing season, or might I expect to get several seasons' worth of use with pea plants?
A Prairie Moon • January 19 If kept in the refrigerator in a sealed container, the inoculum will be good for a year, maybe a little longer.
Q Tim • June 30 How much inoculum do you receive and how many seeds will it inoculate?
A Prairie Moon • July 1 Hello Tim, you receive a 1/2 tablespoon of inoculum and it will inoculate up to 1 lb. of seed.
Q Renee • October 24 How do I know what inoculum to buy for my seeds
A Prairie Moon • October 24 Hi Renee. Determine the genus of your species (ex: Wild Blue Indigo is Baptisia and Wild Lupine is Lupinus). Select that genus name from the "Choose Type" drop-down menu.
Q Diane • January 22 Hi, we are planning to germinate Hedysarum boreale and several milkvetches (Astragalus). We've had past success with milkvetches, not so much with the sweetvetch. Do you have any strains that are compatible with intermountain milkvetches and sweetvetch?
A Prairie Moon • January 23 Hi Diane. We do not have in-house experience determining which inoculum strains nodulate on what plant species, but if the species you are sowing is included in the exact genus listed in our inoculum (like Astragalus), we recommend that. Otherwise, our supplier has shared that the Lathyrus inoculum formed nodules "on most types of vetches." This statement may or may not have included intermountain milkvetches and sweetvetches. He also informed us that the Rhizobium in the Baptisia, Desmodium, Lespedeza, and Crotalaria inoculum tend to be less specific about which species they associate with. You may want to experiment with one - or a combination - of those inoculums as a "general inoculant."
*PLEASE NOTE: we are a mail order nursery and have no retail facilities, but you may pick up your order if prior arrangements are made. Pick up orders are subject to 7.375% MN Sales Tax.

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