In 2014, members of Team Echinacea did an experiment to test methods of removing Hawkweed. Last year Ali assessed the results of the different methods that they used: cutting the head and painting the stem with herbicide, painting the leaves with herbicide, hand pulling with and without tools, and a control treatment. You can read her post describing the experiment and with the results from 2015 update here and the original post with methods here.
I went back to the treatment plots this morning and assessed Hawkweed percent cover two years after the treatment. The plots with the lowest percent cover this year were those where they removed hawkweed by hand, with tools. These plots also had the smallest percent change from 2015 to 2016, indicating lasting effects of removal. This was in contrast to those that had been treated by painting leaves with herbicide, where plots had an average of 4x increase in Hawkweed. From now on, we’ll use this method to remove Hawkweed in P1. We’ll assess percent cover in the treatment plots and the status of other Hawkweed plants in p1 to keep track of our progress at eradicating Hawkweed from the common garden.
Here’s the percent cover data from this year:
Now that we have more evidence that digging up plants really sets back the plants, I can’t wait to dig up more hawkweed! To that end, we just bought all the garden knives in stock at the local Fleet Farm store.