by Bill Kleiman
You likely don’t know invasive Lespedeza daurica. I will tell you why in a bit. But it is similar to the invasive Lespedeza cuneata, but more likely found prostrate like the specimen I put in the pot above. This was years ago, when my daughter and Jay would tell stories and laugh. They are still good buddies.
Lespedeza daurica above. We had made a purchase of a native seed mix from a seed nursery and had ordered Lespedeza virginica, slender bush clover. It appears that this nursery was wild harvesting from the only site in the state with L daurica and sold it to us by error. The occurrence of this invasive legume matches perfectly with all the places we planted that seed mix. The correct Lespedeza is nowhere to be found in those plantings. I informed the nursery once we figured this out, but the damage was done.
We kept trying to key out this Lespedeza to what we ordered, but it would not go there. Nor would it key to anything else. So we sent a specimen to the Illinois herbarium and another expert looked at a specimen. We had half a dozen top botanists view specimens. We were kindly informed that we appear to be one of the few occurrences in the state of this invasive. Such an honor.
This was back in September of 2007. We started to go after this species with vigor. Above, a young Josh Clark is cutting and barreling the plant. We applied herbicide to the cut stems. Today on cut stems we use basal bark mix or concentrated glyphosate. We hauled many barrels away. For foliar spray we use a tryclopyr. Transline does not kill Lespedeza. Plants are hard to dig up but it is possible when soils are soft.
Four of the infected plantings are still here. We dropped the occurrences to a scattering of plants but finding those needles in the prairie stack is an annual challenge. One large planting that was full of this weed we boom sprayed back then, and continue to boom spray. We do this to lower the threat of spreading. That field has been reduced to a sad collection of grass and monocots.
Fourteen years later and we are still doing our annual L daurica weed sweep. We gps locations and we keep pushing. My wife and I were just out at sunset checking a patch. We found about a dozen. Snip, spray, and bucket.
Caveat emptor – let the buyer beware.
I had a similar issue when buying Echinacea augustifolia. We ended up getting a mix of E. augustifolia and E. purpurea. Not only is purpurea not native to our area, but it is actually far less expensive than augustifolia, which we paid market price for. So along with an unwanted plant in our reconstruction we did not get out full money’s worth. Suffice it to say we have not bought from that supplier in a long time.
Wow, yes good advice. Any ideas on how to avoid issues like this? Such as planting in pots before sowing? I assume it’s probably too hard on a big area like you have.
Knowing your supplier very well. Visiting their premises. Looking at who they hire. I don’t know. Nothing easy.