I am considering Lespedeza thunbergii for my shrub border, and I found a document on internet that says:

Lespedeza thunbergii is a legume, so you must obtain the appropriate fresh, viable inoculant.

How to obtain the inoculant for Lespedeza thunbergii? Why do I need an inoculant at all? And, by the way, what is an inoculant?

  • I went to look you up again. I think gardening was a bit of an odd choice for you yet PERFECT. Quite the spectrum of styles...interesting VividD. – stormy Jan 5 '18 at 21:52
  • And now I am remembering your property with the neighbors and Stone Pines? Living on a hillside with a basement full of moisture? This would be a super plant as long as it is planted with great drainage. No wet feet. Actually, very nice plant for your slopes and walls. Oh I would get at least 5 or 7 plants. Can't believe I've forgotten your property. I would also get a shovel and dig at least one trench from your foundation, down to the footing and slope this excavation so that you are able to see the water that is affecting your foundation. Just an idea... – stormy Jan 6 '18 at 1:14

all about innoculation of soil for legumes

Hey there Vivid! Great question, I had to go look this up because the information in my head about legumes was pretty dusty.

Legumes are able to take Nitrogen out of the air and fix it in the plant's 'body'. This is similar to the process of photosynthesis where plants actually 'fix' the Carbon from atmospheric CO2 and give off O2 and H2O.

For Legumes to 'fix' Nitrogen there is a very special 'bacterial innoculant' for the soil that works together with the plant to fix Nitrogen. It is commonly found in most soils but they advise you to coat your seeds before planting or add it to your soil when planting legume starts/plants.

Beautiful plant though a bit wild. I would plant this where it has lots of room to grow. Space these shrubs 5 to 10 feet apart; have each shrub be the point of an Scalene Triangle. No sides equal in length. Perfect spot would have coniferous shrubs in the back ground, evergreen ground cover in front. Winter, you'll be pruning these to the ground so think about the hole that will be left in the landscape all winter long.

Drainage, doesn't like wet feet, the crappiest soil would be just fine. This guy grows fast and the more room you give it the bigger and faster it will grow. But you still want a group of these, at least 3 in a group and one on the other side of the landscape all by itself. Where you can see all 4 from most views.

Otherwise, this plant would do well solo.

Why I have not associated you with a spot on this planet yet is frustrating. Take a picture where you want to plant these shrubs...I love this vase/arching form. Also, are you allergic to bees?

This is a product to innoculate the soil for legumes. innoculate for soil of legumes

Found this article that explains the chemistry and process and plant fairly well. I am seeing that adding just a little of the proper bacteria to the soil (under 10 bucks) will ensure the health of a legume. Specific bacterium for different legume plants. This I did not know.

What this means is that you have to be careful adding fertilizer. The plant is making its own nitrogen. Adding too much nitrogen will actually stop the nitrification process. Adding too much nitrogen will also inhibit any flowering or pea making for us to eat. Extremely low nitrogen in proportion to phosphorus and potassium.

I get the feeling that adding the inoculant and holding back the nitrogen fertilizer would be best for the health (and sanity?) of your shrubs. Inoculants are used to enhance commercial growth of legumes and reduce costs. I found a site talking about just this plant you want to grow which is an ornamental not an agricultural product and they went out of their way to talk about adding inoculant. I think your plant will grow just fine without...heck, I never added inoculant except for my veggie gardens and the ornamental legumes grew and looked...fine. I am perplexed that inoculants would be recommended for legume ornamentals. I am intrigued big time. I would definitely try use of an inoculant. Let us talk about the place you are thinking to plant this rather breath taking super hardy easy care plant. Okay?

specifics with legumes and inoculants

more information about inoculant


You don't need an inoculant to grow it, it will grow perfectly well and flower well without one. The only reason to use an inoculant is to promote and strengthen its nitrogen fixing root nodules, usually with the intention of improving the fertility of the soil they're planted in when planted as a cover crop or crop. The plant produces these root nodules anyway, though likely their ability to fix nitrogen is exacerbated by using an inoculant. If you just want to grow it as an ornamental shrub, you do not need to get an inoculant.

Considered invasive in some areas, hardy down to between -15/-10 deg C, information on growing as an ornamental plant here https://www.rhs.org.uk/Plants/73337/Lespedeza-thunbergii/Details

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    He wanted to know what an inoculate was, did, how used, why recommended...the health of a legume adds a new dimension to a plant's needs. To be able to do its nitrogen fixing gig it has to have at least some of the proper bacteria to do the job. It is cheap to purchase. Educational about the proper bacteria for the proper legume for sure (I didn't know about the compatibility issue). I am unsure about the health of a legume that is unable to do the nitrogen fixing process because of the lack of bacteria necessary for the job. Oh, I am just now remembering his property! Wet. Large... – stormy Jan 6 '18 at 1:05
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    @stormy - yes, but I'm more interested in where that quote about inoculant came from - probably from something about growing it as a cover crop or just a crop, because there's no 'must' about it if grown ornamentally, so I suspect its out of context, since the person wants to use it in a shrub border, not as a crop. But nothing wrong with answering the question literally, as you did, its interesting information anyway, my answer's not meant as a criticism of yours – Bamboo Jan 6 '18 at 1:09
  • No problem at all Bamboo...I am getting conflicting info as well; he looked up this plant which is ONLY used for ornamental purposes. I thought the inoculant for seeds had to be commercial. I think I sent a site that specifically discussed this ornamental almost weed legume needed an inoculant. Like ALL legumes need this...so I am out looking to see if there is a problem for legumes in terms of health to not be able to do nitrogen fixing...something I've never thought about...weird that they would give these directions for an ornamental legume. – stormy Jan 6 '18 at 1:18
  • @stormy not if the plant is being grown as a cover crop... you know, where the topgrowth is cut down at the end of the growing season, but the roots and their nodules left in situ... you'd get more nitrogen in more nodules if you used an inoculant I imagine – Bamboo Jan 6 '18 at 1:21
  • @stormy Check out 'cultivation and uses' in this link for Lespedeza generally en.m.wikipedia.org/wiki/Lespedeza#Cultivation_and_uses – Bamboo Jan 6 '18 at 1:26

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