By Clara Barton
Hello, my name is Clara Barton, I am the new Invasive Plant Monitoring Technician for Nachusa Grasslands. I recently received my master’s degree in ecology with a dissertation focused on studying the spatial biodiversity of grasslands. I worked as a seasonal restoration technician on the crew here at Nachusa in 2023 and 2024. Before that I was a restoration technician intern for the Missouri Botanical Garden’s Litzinger Road Ecology Center. Through my work, education, and research experiences, grasslands have become a cornerstone of my life. Spending time in prairies has taught me so much and given me a great appreciation for the amount of work required to maintain these absolutely gorgeous ecosystems. Having a background in research and restoration has set me up well for this new position at Nachusa.
As the Invasive Plant Monitoring Technician my job is to run experiments to evaluate the methods we are using to manage invasive plant species at Nachusa Grasslands. I will be looking into many weeds including Honeysuckle (Lonicera maackii), Birdsfoot trefoil (Lotus corniculatus), yellow and white sweet clover (Melilotus officianalis, Melilotus alba), Sericea lespedeza (Lespedeza cuneata), and more. I will be focused on which herbicides are effective, mowing practices and timing, and if treated plants are still producing seeds.
The goal of these experiments is to make sure the measures we are taking to control an invasive species are working, as well as finding out if there are any treatments that would be more effective. I intend to make blog posts here about each experiment I conduct. Sharing what I learn here will hopefully benefit many other restorations that may be struggling with the same invasives.
Some of the questions I am currently working on right now include:
- What herbicide works best for Butter and eggs (Linaria vulgaris)
- Do mowed sweet clover stems resprout?
- Do mowed sweet clovers still produce seed?
- At what stage in seed development does Wild parsnip need to be hauled off after spading?
- What herbicide is best for treating bouncing bet (Saponaria officianalis) and how much surfactant is effective?
- What works better for Crown Vetch? Transline or Milestone?
- What herbicide is most effective for foliar treating honeysuckle resprouts?
- Is the Carpet wick effective at killing unwanted woody plants?
I work together with Bill to come up with the questions that need answering to best help us with our work. If you have any questions about invasive plant management, feel free to put them in the comments. We are always looking for more questions to investigate to help with the greater effort of restoration.
I look forward to sharing what I find!
grassland restoration network 
You are exactly what the restoration community needs & your experiment list is a good one.
The sweet clover experiment should include plants with stems that originate at or below ground (at or just above the root crown). The question is whether such plants will reflower no matter how low they are cut. Also what bloom stage at cutting will ensure no viable seed will develop on the cut stems. For the last point, the same applies to parsnip.
Crown vetch experiments should include various adjuvants with the goal of finding a method that only requires a year or 2 to kill the root. For example, there are reports that Dyne-amic surfactant combined with a sticker worked well with Transline but we need a more detailed test.
I’m currently experimenting with dogwood reduction combining cut stump herbiciding with burning & cutting. This is a very complex issue that will require several long term experimental treatments.
Thank you for this comment. It sounds like you are experienced in investigating these issues.
The timing for sweet clover really makes or breaks success with mowing is what I have always heard. I am monitoring some yellow sweet clover that was mowed in the spring and watching the resprouts carefully to see how they mature. Your point about stems originating at or below the root crown is a good one, and I will keep an eye out for those plants specifically to see whether they are able to reflower regardless of cutting height. Might use some white sweet clovers to investigate it separately. I also have some pots with the clippings from the mower/ spaded plants to see if any viable seed is produced.
I will look into the adjuvants for crown vetch, right now my experiment is looking at transline vs milestone to treat it. Both with MSO to increase the absorption. There is plenty of crown vetch blooming around right now and I could absolutely try some other adjuvants. Great suggestion.
I see Bill has given you my email. I look forward to hearing about the experiments you have been working on, and what you are finding with your dogwood experiment. Hearing people’s observations is the first steppingstone in setting up these experiments.
I look forward to hearing your results for all these invasives! I am battling them all. In addition we have some Canada thistle patches. I am having better luck with those by doing multiple cuttings within two to three weeks windows. But I would like to know:
if you cut thistle when it is blooming, do you need to haul it away? At what point does it still produce viable seed, and what percentage of the seed is viable?
Thank you for your commitment to prairies!
Peggy Timmerman
Lone Rock, WI
It is good to know that multiple cutbacks are working for you with the thistle. We have few thistle patches here, so I haven’t had much opportunity to work with this weed.
My understanding is that for most plants the risk of viable seed production depends heavily on the flowering stage when the plant is cut. If flowers are just opening, the risk is lower than if seed heads are already developing, but I don’t know exactly where that threshold occurs or what percentage of seed remains viable after cutting.
I am currently running an experiment where I have collected parsnip and sweet clover at different flowering and seed-development stages to determine when it is safe to leave the cut plants in place versus when they should be removed. I suspect the same methods could be adapted to answer this question for Canada thistle as well.
Thank you for your comment!
This is very exciting news! I will be following along with this blog. I too work on the invasives here in Austin. We use fire regimes to help combat certain species. I know Nachusa has used prescribed fire as well, so I will be curious if you see some good results after any of those burns. We find a good summer burn helps knock back KR bluestem Bothriochloa ischaemum var. songarica . I am about to try my first stab at tackling huge swaths of Johnson grass, Sorghum halepense.
Good luck with the new project!
Leslie Uppinghouse
Leslie Uppinghouse (She/ They)
Land Steward, ISA Certified Arborist
Lady Bird Johnson Wildflower Center
The University of Texas at Austin
wildflower.orghttp://www.wildflower.org/
Inspiring the conservation and cultivation of native plants
I forgot to include this in my post but I would like to extend a special thanks to our retired steward Gerald McDermott for helping make my position possible!
Hi Clara, I think I might have met you a year or 2 ago at Skokie Lagoons birding at the end of the day? Either way, congrats on your new job! One thing I was thinking about, and I did recently see someone might be looking into this already, is is it best to burn buckthorn after cutting it down (or others)? It releases a lot of smoke and can also damage the ground, so why do it?
Suzanne
Congrats Clara!I’d be interested in knowing at what point is Milestone is no longer effective in preventing production of viable seeds of Birdsfoot trefoil seed: when the pods are full-size but green is it too late to herbicide? Presumably when the pods have turned black it’s too late?
I may write up a smaller blog post about this. I had an experiment on Birdsfoot trefoil using different herbicide mixtures that I applied late June. The plants were only flowering when I applied the herbicides (Transline, Milestone, etc) and they still ended up going to seed. I am not sure how viable the seed is. I may collect some and see if it fully matures. This would likely be more of an observational insight post, a more organized and formal study on this topic would be really helpful. I will definitely be looking into this idea further, thank you!