Tom's Blog

Tuesday, July 10, 2018

Learning about weeds: a personal account

At Pleasant Valley Conservancy we have dealt with weeds in our prairie remnants, our restored oak savannas, and in the prairies we have planted in former agricultural fields. Each situation presented different problems and required different solutions.

I admit I was surprised when Paul West told us in the summer of 1997 that hand-weeding would have to be done on the South Slope. All we had done so far was cleared and burned Kathie’s Prairie. How could there be weeds already? Not woody plants, but herbaceous ones. Weeds he specifically mentioned were wild parsnip and sweet clover. Later, mullein and thistle entered the picture.

Obviously, our restoration work had not created these weeds. They had already been there. So it was not only woody vegetation that we would have to deal with. I finally got accustomed to the idea that weeding was one of the major activities of restoration ecology. And in natural areas, weeding was often hand work, although weeds could sometimes be dealt with by mowing or spraying.

Paul West spent 6.5 hours pulling primarily wild parsnip on Kathie’s Prairie in July 1997. In July 1998 he and Pat Schrader spent 16 hours. Again, mostly wild parsnip. In 1999 the hired crew pulled no weeds as this was the year the whole South Slope was cleared, and burned, but Kathie did a lot of weeding (see below). But in the year 2000, West, Schrader, Michler, Brown, and Nate Chisholm among them worked almost 1000 hours pulling weeds, almost all on the South Slope!

Although most of the weeding in 2000 was on the South Slope, weeding was also done on the County F and Pleasant Valley Road cuts. Also at a scrubby area at the corner of PV Road and County F (Unit 14), and Toby’s Prairie (quite a bit, as this was in its second growing season).

In the early years, all the weeds were pulled by hand. This requires a strong back and strong arms and shoulders. Most of the folks pulling weeds at PVC were young and strong, and seemed to have no trouble. However, as the weeds age their root systems get larger, and eventually they get to the stage where they really can not be pulled. A strong person will end up just breaking the stem near the base. This is when you start thinking about a shovel.

Kathie’s notes on early weeding: “June 8[1999]. KMB to farm. Cleared brambles and brush above K’s Prairie—v slow work: 3 hours—will allow prairie to climb higher” [up slope]
June 10. KMB to farm—HOT; worked on more brambles and brush on K’s Prairie; 3 hours
June 14, 99 GREAT WEATHER T and K clipped brambles and brush on K’s prairie for 1.5 hour (-3 hours)

6-15 [1999] K only, 4.5 hrs; Cut clover and pull parsnips ~2 hrs. Lots of clover in middle area(s) or rocky prairie. Lots to do! Cleared patch near SE corner of K’s prairie. Should extend work from here. Also lots of clover on road cut below K’s p. ~2.5 hrs—cleared more @ top of K’s prairie

6-17[1999] K and T 4 hrs Sweet clover and Parsnips off road cut below K’s prairie…K: Cut clover, too hard to pull as so many (5-10) stems! Hope it doesn’t resprout. T: sweet clover and esp. parsnips along PV road

Aug 3, 99. K to farm. Willis here too…Most of sweet clover and parsnips now removed from whole area and Willis is pulling Q Anne's lace.

Aug 11 K to farm…Clipped brambles at base of K’s prairie and east 1.5 hrs

Broader weed activities
Kathie and I first got involved in invasive plants through our work at the Campus Natural Areas on garlic mustard. In fact, garlic mustard became a major issue for us for a while. Kathie discovered major infestations of garlic mustard in Shorewood Hills, and got a number of village residents involved. She got the Village Board to declare garlic mustard an official “noxious weed”, which led to lots of work in the village. Kathie organized volunteer work parties to control garlic mustard on village land, and she and I did lots of garlic mustard work on our own.

Then there was the very important meeting called “Plants Out of Place” (acronym POOP), held in March 2001 at Eau Claire. This meeting was held in association with meetings of The Wild Ones (the day before POOP) and The Prairie Enthusiasts (the day after POOP). With all these meetings, attendance at POOP was over 600. Kathie and I attended both the POOP meeting and the TPE meeting. I really revel in this sort of high-level meeting that provides a great summary of expert scientific information.

In addition to the meetings, there was an extended discussion among the presenters and attendees of how control of invasive plants could best be accomplished. This was one of those sessions where people wrote topics on large sheets of white paper hanging around the sides of the room. One of the major “conclusions” was that a new organization was needed that dealt with invasive plants of Wisconsin.

All those interested in this idea were invited to attend an evening meeting to formalize this organization. Kathie and I attended this meeting. TNC’s Nancy Braker, who Kathie had worked with extensively, was the secretary of the meeting. I ended up sitting in the middle of the table, which led me to do a fair bit of talking. When it came time to select officers for the new group, I was asked to be President. Since Kathie and I were so heavily involved in our own restoration work, I declined, but volunteered to be Treasurer. Before the end of the evening, it was decided to call the organization the “Invasive Plants of Wisconsin” (IPAW). In order to incorporate we needed Articles of Incorporation, which were written that evening. The By-laws, needed to get non-profit status, were written later by the Board of Directors.

As Treasurer, my responsibility was to get the organization started. I took all the checks that had been written by potential members and on return to Madison made the application to incorporate with the Wisconsin Department of Financial Institutions. The fee to incorporate came from my personal checking account. IPAW was officially incorporated on March 8, 2001, just a week after POOP was over. Once I had the official name, I got a tax ID number from the IRS, started a checking account, and deposited all the checks. With a bank balance, I was now able to write checks. I rented a post office box at the Hilldale Station (Box 5274, which still exists). I checked the P.O. box for mail weekly, and was pleased to see checks coming in.

The membership list was being maintained by the Executive Director of The Wild Ones, so as checks came in, I deposited them and sent the names and addresses on to her. I wrote a thank you note to every new member. With the Board of Director’s help I put together the papers necessary for becoming a non-profit organization and sent them off to the IRS. In due course, the letter came back making us a 501-(c) 3 corporation.

The other activity I played a major role was getting a good web site for IPAW. One of the new members, Marsha Vomastic, had volunteered to set up the web site. She was an experienced web designer and she and I worked together. I wrote quite a bit of the website content. Although the design has now been updated, Marsha’s web site served IPAW well for many years.

Because I was so intimately involved in the creation of IPAW, I quickly became very familiar with the biology and control of Wisconsin’s invasive plants. With my strong scientific background it was no problem reading the scientific literature in this field. And we had our own Conservancy as a test case for control methods!

Here it is 17 years later and weeding is still necessary, although lots less than in 1998.

Weeding at Black Earth Rettenmund Prairie
Kathie and I became stewards of this fine prairie remnant in 2001. By that time we were beginning to understand sweet clover fairly well, and BE was heavily infested. In those early years, the patches were very large, and had to be mowed.

Sometime around 2009 or 2010 mowing was no longer necessary, but hand pulling is still essential. Although volunteer work parties are held regularly, the fact is that most sweet clover work at BE is done by hired help, although for about 10 years we also used paid interns.

At one time I thought we might be able to eradicate sweet clover from BE, but I no longer believe this. However, some  years it is worse than others. This year is especially bad.

Why is sweet clover so bad at BE when the prairie itself is so good? After the Nature Conservancy acquired BE Prairie, considerable effort was put into sweet clover control, but as the years went by, work focused more on brush control. In the year 2000 only 7 hours were spent on sweet clover control. If sweet clover is not eradicated, seed formation will occur, adding to the already rich seed bank. The main reason Kathie and I took over stewardship in 2001 was because we were concerned about the sweet clover problem at Rettenmund Prairie.

Contractor mowing sweet clover at Black Earth Rettenmund Prairie, July 2005

Saturday, June 30, 2018

Prairie and savanna plant species present at Pleasant Valley Conservancy before restoration

We were fortunate that in 1995-1997, before any restoration work had begun at Pleasant Valley Conservancy, several plant species lists were prepared by competent botanists. Later, after Kathie became more familiar with the property, she added more species.

I put these lists together and added quite a few other species that had been missed because they were in remote parts of the property or would not have been visible at the time of year when the original observations were made.

There were 307 species that were present before any restoration or seeding, which is impressive. Also, quite a few of these species are very desirable, with high Coefficients of Conservation (C values).

As part of my work on the history of PVC, I was interested to see where these species had been originally found, thinking that may give some idea of how they were able to hang on without human help. The table shows the principal locations, and lists the most interesting species.

In the very high quality 1990 air photo shown here the locations of the two largest prairies can be seen. Also there are quite a few smaller areas that had not (yet) brushed in.

County F road bank
Mostly savanna; a few also found in prairies, lots of golden Alexanders; important collecting site, especially for savanna species
North Woods
Large populations of Trillium grandiflora and large lady slipper orchid
Toby’s Annex
Flowering spurge, Missouri goldenrod, Showy goldenrod, little bluestem, Indian grass
Unplowed north side of what is now Toby’s Prairie
Large population of Baptisia alba
Kathie’s Prairie (Unit 1)
Lead plant, sky-blue aster, purple prairie clover, small yellow flax, fringed puccoon, short green milkweed, Agalinis gattingeri, violet wood sorel, small skullcap, blue-eyed grass, gray goldenrod, prairie dropseed, bird’s foot violet
Tom’s Prairie (Unit 4)
Lead plant, sky-blue aster, fringed and hoary puccoon, violet wood sorrel, prairie turnip, blue-eyed grass, prairie dropseed, bird’s foot violet, prairie violet
Remnant area of Unit 11A
Lead plant, New Jersey tea
White Oak Savanna
Large population of shooting star
Unit 18
Virginia wild rye, spiderwort, white baneberry,  red baneberry,
No seeding has been done; sweet Indian plantain, glade mallow, swamp milkweed
Oak savanna areas
poke milkweed, purple milkweed, spikenard, wild sarsaparilla,

In addition to these larger sites, a number of smaller prairie remnants existed at Pleasant Valley Conservancy at the time restoration work began. Most of these were areas that had not been plowed, or had been too far from the barn for much grazing. Some of these remnants were important because they were the sources of seeds of particular prairie or savanna species.

Seeing this summary makes one realize that there is good hope for many other so-called degraded sites!

A detailed study of the 1990 air photo is interesting. Many south-facing hillsides like this one had at this date been completely covered with red cedar, which is very invasive and spreads rapidly. Why is this slope still fairly open?
The photo was taken before leaf-on, so the only green seen are conifers. However, almost all of these conifers were red pines that had been planted by a former owner. There were a few red cedars, but only scattered. I think the presence of the pines had kept the cedars from taking hold. And the rest of the vegetation on the south-facing slope was deciduous, either shrubs or trees.

We began clearing this hillside in the winter of 1997-1998 and finished it in 1999-2000. Now with many burns and extensive seeding, it is a highly diverse tallgrass prairie!

Air photo taken April 13, 1990 (from Dane County Regional Planning Commission)

Thursday, June 28, 2018

Baltimore checkerspots at Pleasant Valley Conservancy

The Southern Wisconsin Butterfly Association has had its June fieldtrip at PVC for the past seven years. One of the attractions has been the chance to see the Baltimore checkerspot, a small colorful butterfly which is not very common. (In Maryland, where it is the State butterfly, it is considered very rare.)

This year at PVC was no exception, and 23 checkerspots were counted. There were probably a lot more than this count. In fact, they seemed to be all over, even “puddling” in the barn’s dirty gravel apron. (I saw 5 there three days later!)

The whole butterfly trip was great this year, with an exceptional show of butterflies. Checkout the SWBA website for the complete report.

We seem to have the right habitat for checkerspots. Their primary host plant is turtlehead (Chelone glabra), an attractive wetland plant. Our wetland apparently is good habitat for this plant. I should emphasize that we burn the wetland frequently, which may help. In fact, after Fish & Wildlife Service first burned it in 2005 we saw over 100 turtlehead plants in flower!

Another interesting tidbit is that we had turtleheads and checkerspots here even before any restoration work was done. In 1995 we had hired Brian Pruka as an early consultant on our restoration work. He wrote the following analysis of our wetland:

“This Driftless Area wetland is…fed by groundwater from the adjacent bluff. Thus it has fen character to some degree….I tried to locate as many fen-loving species as possible and was delighted to find Turtlehead…which blossoms in late August and early September….Equally exciting was when I sighted a Baltimore Checkerspot butterfly. The Baltimore is one of Wisconsin’s most exotically patterned butterflies….The caterpillar…feeds exclusively on Turtlehead; thus it too is a fen-dependent species.” Wisconsin Wetlands Association Newsletter 1995.

I have compiled a list of over 300 plant species that were present at PVC before any restoration work had begun. The bulk of the species on this list came from Brian Pruka.

Thursday, June 7, 2018

10th anniversary of Pleasant Valley Conservancy State Natural Area

Although Pleasant Valley Conservancy State Natural Area was actually created when Governor Jim Doyle signed the official document in 2007, the dedication ceremony was not held until 2008. Today is the 10th anniversary of that ceremony.


June 7, 2008
1:00 PM-1:30 PM
Pleasant Valley Conservancy State Natural Area
Town of Vermont, Dane County, Wisconsin

Evanne Hunt, President, The Prairie Enthusiasts

Signe L. Holtz, Director, Bureau of Endangered Resources, Wisconsin Department of Natural Resources

Mark Martin, Natural Areas Specialist, WDNR

Richard Henderson, Vice President, The Prairie Enthusiasts and President, Empire-Sauk Chapter, Prairie Enthusiasts

Darcy Kind, Landowner Incentive Program Conservation Biologist, WDNR

Kathie and Tom Brock, Landowners, The Savanna Oak Foundation, Inc.

Field Trips
1:30-3:30 PM

Prairies and Savannas at Pleasant Valley Conservancy: Rich Henderson

Wetlands and Reed Canary Grass Research at Pleasant Valley Conservancy: Craig Annen, Integrated Restorations, Inc.

Birds: Dave Sample, Research Scientist, WDNR

How the Restoration Work Was Carried Out, Willis Brown, Michler and Brown, LLC

How We Got Started: Kathie and Tom Brock

Refreshments After the Tours

Exhibits and Refreshments in the Barn

See Over for Public Trail Map

 We had sent out invitations to various mailing lists, and the event was announced in the local papers. We set up a registration table under a shade tree, and provided name tags. The count (I still have the sign-up sheets) was 118, and there were probably some who did not register.

Anticipating a good turnout, we set up several field trips, some short, some long. The trips are shown on the program.

Kathie and I chose Saturday June 7 as the dedication date because the Conservancy would be looking fresh and lush, and the weather was likely to be good. We had had a very successful spring burn season. Unfortunately, the weather made a wild change in mid-afternoon, ushering in a weekend of heavy rainfall. We missed the line of tornadoes that streamed across northern Illinois but not the “historic” flooding that inundated southern Wisconsin. This was the weekend that Lake Delton disappeared and Lake Mendota overflowed its banks.

Fortunately, most of the “events” occurred before the rains came, although most of the field trip participants got soaked, and moved eagerly into the barn where the refreshments were laid out. Those significant numbers who came on bicycles had a little trouble getting home.

Photos by Jim Hess

Registration table

Tom and Kathie

The "ceremony" took place near the cabin


Rich Henderson's field trip was well attended

After the deluge

National Weather Service
Historic Flooding of June 7- 8, 2008
2008 blog post on the flooding.

The next day
As it happened, on Sunday morning June 8 Kathie and I and Roma Lenehan were scheduled to lead a birds and wildflower trip for the Natural Resources Foundation. Despite the threatening weather, 20 people showed up for the trip to start at 9:00 AM. The heavens opened up at 8:55 AM and blinding rain occurred until 11 AM. The three leaders lectured in the barn, using the exhibits that were still standing from the day before, until the rain stopped. When we finally could hike we even saw some birds!

Thursday, May 10, 2018

Invasive plants: Complete eradication is important!

How important is it to eradicate "all" the bad guys? I posted on this some years ago, but it deserves repeating.

One important part of restoration work is planning brush and weed removal. The question often arises: how important is it to get rid of "all" of the invasives? Eradication is expensive; do we really need to eliminate every last sweet clover sprig or buckthorn stem?

If one is thinking of the long term, the answer to this question is "Yes". The reason? Because annual stewardship cannot be assured. All sorts of reasons might arise that would prevent continued restoration on a preserve. Money problems first come to mind, but passing on or moving away of key personnel may be more important. What happens if work is stopped on a site before it is completely cleared of bad stuff? In a few years, bad plants will start to appear, and in a few more years there will be more.

At first these "stragglers" may seem acceptable, but this is just what microbiologists call the "lag" phase. Eventually the "log" phase is reached, and the site will suddenly "explode" with invasive plants. With exponential growth, it is the last doubling that turns the site from tolerable to hopeless. One year the site may look more or less OK and the next year it is ruined. That final point where everything suddenly becomes ruined is sometimes called the “tipping point”.

However, if the bad stuff has been completely eradicated, then the site should be able to stand some neglect, with perhaps just an annual or biennial prescribed burn. (But don't count on burns to get rid of new invaders! This won't happen.)

Even more important: if all invaders have been eradicated, it becomes a very inexpensive process to remove the few new ones that move in from outside. One or two passes through this blissful preserve may be all that is necessary each year.

Thinking of the budgetary and personnel problems, which is more important? A smaller area completely restored, or a larger area partly restored? The answer to this interesting question may depend to a great extent on the goals.

For instance, if the goal is to provide habitat for grassland birds, then large open areas are critical, but they may not need to be completely weed free. Indeed, some grassland bird species seem to be reasonably happy with a field of Queen Anne’s lace or even an alfalfa field, as long as it isn’t mowed too early.

But if the goal is preservation of plant diversity, then smaller sites with high botanical quality will be more important.

The ideal time to canvas a fully restored site for new invaders is mid-October, when the native vegetation has senesced. Exotic invaders such as buckthorn and honeysuckle keep their green leaves longer, and the occasional straggler (or new invader) really stands out. Carry a backpack sprayer filled with aqueous Garlon 3A or glyphosate (foliar spray concentration) and spray the green leaves. The senesced native vegetation will not be hurt, and the invader will be killed.

Honeysuckle green among the senesced native vegetation. Perfect time to spray.

Even a single buckthorn plant can be found hidden among the native vegetation!

Wednesday, May 2, 2018

Plant ecology and soil characteristics of a Midwestern bluff prairie

 What we call the South Slope is a classic Midwestern bluff prairie. A few years ago (2014) Peter Hartman and crew from the USDA-NRCS came and studied our South Slope as part of their work to develop a “site description” for bluff prairies.

Our South Slope is part of what the NRCS calls the Northern Mississippi Valley Loess Hills, a region which includes parts of four states: Wisconsin, Iowa, Minnesota, and Illinois. Two other terms sometime used are the “Driftless Area” and the “Paleozoic Plateau”. The latter term is used because the bedrock formations are from the Paleozoic Era, sedimentary dolomites and sandstones from the Ordovician and Cambrian Periods.

The soils were formed during the 450-500 million years since the rocks were first laid down, and then were followed during the last (Wisconsin) glaciation by a layer of fine silt (loess). This loess layer was laid down during a xeric period after the glacier had receded (10-15,000 years ago).

Most importantly, the steep bluffs are covered by colluvium, a term which describes the loose rocky fragments that move downslope either by rainfall or by slow down-slope “creep”.  These extremely rocky soils are called sometimes called flaggy (like being derived from flagstone), channery (with flat coarse fragments) or cobbly (rounded stones). These are more refined terms for soils I have always just called “rocky”.

The rocks and other fragments derived from bedrock are especially obvious after a burn.

I had always assumed that if our soils were so rocky that bedrock was right below the surface, so there was essentially no soil at all. Wrong! The soil layer is many feet thick!

The photo shows the site crew at work. Note the tall thin rod with a handle at the top. One of the crew members actually inserted that rod into the bluff all the way up to the hilt, five feet. Indeed, according to the site description, these soils are 4-5 feet thick.

Peter Hartman and his NRCS crew working on the South Slope (Unit 1) on June 3, 2014. Note the long rod with handle, standing to the right. This rod was later pushed vertically right up to the handle.

The rocky soil after a burn. Most of the rock fragments are derived from the dolomite bedrock up-slope. Not all the surface is this thick with rocks. The thick soil layer can be found below and between the rocks. Grasses like little bluestem and forbs can grow between the rocks, sending their roots deep into the soil. March 26, 2010

Little bluestem bunches just starting to grow, South Slope (Unit 5), April 11, 2016.
The Slope was burned on March 11, 2016.
Late summer lush little bluestem bunches growing out of the rocky South Slope soil. Sept 27, 2016.
Cross section of part of a typical bluff prairie habitat. The South Slope bluff at Pleasant Valley Conservancy has another layer (Tunnel City Sandstone) below the St. Lawrence Dolomite.

When walking uphill across the South Slope, one crosses over four bedrock layers. Because it is at the top of the hill, the dolomite layer is the most important. In fact, dolomite rock fragments can eventually find there way all the way down the hill. Although loamy (from the loess), they may contain more than 35% rock fragments. These soils are excessively well-drained, so there is never a zone where water is saturated.

“Typically, on these dolomite sites, the loess and dolomite rock fragments are thoroughly mixed.” The soil is generally alkaline (pH greater than 7). At PVC I have found soil pH values as high as pH 8-8.5

Typical plants on the dolomite slope.
Consistent with the general description by the NRCS, our South Slope is covered by large, open prairie. Breaks in the slope, due to changes in the underlying bedrock, may alter the species. The most common species are little bluestem and Indian grass, with scattered forbs across the site.

It is well established that the vegetation of these bluff prairies depends strongly on frequent fire. Without fire the sites gradually become brushed in and/or covered with red cedar. The bluff prairie plants cannot tolerate shade, especially that from the dense red cedar cover, and quickly disappear.

Historically, these dolomite slopes were burned frequently, which maintained the prairie and prevented the invasion by woody plants. Out restored South Slope is burned annually.

Although prairie grass predominates, there are always flowering forbs on the South Slope. Unit 3, Aug 9-2011.

Early fall view of the South Slope. Depending on the amount of summer rain, the grass may be either little bluestem (dry years) or Indian grass (moister years). Unit 3/3A 9-22-2014

Wednesday, April 25, 2018

Finally: Good weather for controlled burns

We’ve been burning so much this spring under marginalweather conditions,  that it was a surprise yesterday to have ideal weather for our burns. Not only did we complete our regularly planned burns, but we were able to re-burn many of the units that had not burned well in the February and March burns. As Amanda said: “The day everything burned REALLY well”.  At 10 AM the temperature was over 50 F and the R.H. was 42%. By mid afternoon it was 70 F with RH around 30%.

Of course it was April 24, very late for us to be burning, but you have to take what you are given. Fortunately (?), the very cold April kept almost all of the plants underground, so they were protected from fires. The few species that had already shown a few shoots above ground should have no trouble re-growing from dormant root-stock.

Why do we burn with marginal weather? Most of our burns involve oak savannas or woodlands where burn conditions are often iffy. However, it is so important to get these burns done that we do them when we can. The idea is that we can create reasonable peripheral black lines and get as much of the interior burned as possible. Then, if better conditions arise later, we can go back and re-light areas that did not burn well. And this is what we did yesterday.

Unit 10 savanna burn of Feb 27-2018. Although black, there is a lot of unburned thatch. 

The same savanna after the re-burn on Apr 24, 2018.
Complete combustion, as shown by the white ash

In contrast to savannas, prairie burns can generally be very successful in marginal weather conditions, provided the fuel is fully cured and the dead fuel moisture low enough. The same day that our savanna burn was not very successful, the nearby prairie burned very well.

No thatch left after this burn of Feb 27, 2018