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