Sumac control at Black Earth Rettenmund Prairie

Despite biennial burns, sumac has remained a significant problem at Black Earth Rettenmund Prairie. We now know how to get rid of it (basal bark with triclopyr). But we need to know where it is, and find the time to work on it.

Today I made a survey of the whole site, looking for sumac clones. This is an ideal time to do this, as all the clones stand out as bright red patches, especially in this nice sunny weather .

I used my GPS to mark the clones, and then transferred the resultant Excel file to ArcGIS. We'll use the resultant map to plot out a strategy for the spraying work.

We divide Black Earth Rettenmund Prairie into four separate units: North, Saddle, Narrows, and South. The North unit is the largest, and is the area that was in the best shape when the Nature Conservancy acquired the property in 1987. In keeping with a widely accepted control strategy, we thus worked on that unit first, and this year sumac is now fairly well controlled. A few volunteer work parties helped, but the main control work was by one of our interns (Lauren), plus some other paid help.

The Saddle has some major clones, especially on the east side near the service lane, and on the west side along the stone wall that separates the Prairie from the adjacent private land. We have already started work here and will try to finish here before the snows come.

The biggest clones are in the Narrows, especially along the fence line. This isn't surprising, since the fence line had been quite wooded when TNC acquired the Prairie, and real restoration work did not get started here until Kathie and I took over management about 8 years ago. (Since our efforts have mainly been invested in sweet clover control, it is not surprising that the sumac has remained a problem.)

There is also a large clone along the fence line in the South Unit, as well as several smaller clones. Again, these clones are in areas that had been wooded.

If we have a light snow year, we might be able to finish the whole site. The nice thing about basal bark treatment is that it can be done any time of the year.

However, our research has shown that you can't eradicate sumac by a single pass. There are always root suckers, so this work will have to continue into 2011 (and beyond...?).