Dane, Sauk, and Columbia Counties

Black Earth Rettenmund Prairie State Natural Area


Tom Brock presented a paper at the North American Prairie Conference in Winnepeg on the long-term restoration work at TPE's Black Earth Rettenmund Prairie. The paper was published in the Conference Proceedings.


This prairie was once rated among the top ten natural areas in Dane County in private ownership. It was used by plant ecologist John Curtis as an outdoor classroom and was one of his prairie sites in his classic book Vegetation of Wisconsin.. The University of Wisconsin-Madison herbarium has numerous entries of plants collected at this site, some dating back many years.

The preserve is in the drainage basin of, and is within site of, Black Earth Creek, one of the outstanding trout streams in southern Wisconsin.

See link for a detailed species list.

Although weather varies from year to year, the best time to see the wood lilies (Lilium philadelphicum) in bloom is often the third week of June. This is also a good time to see other species that flower in early summer.The best time to see the large display of butterfly milkweed and lead plant is usually early July.


Compass PlantOwnership
Black Earth Rettenmund Prairie is owned by the Prairie Enthusiasts and managed by the Empire-Sauk Chapter. Stewards are Tom and Kathie Brock.

Dane County. T8N-R6E, Section 27 SW&frac14. The site is 16 acres in size.

From the intersection of Highways 78 and KP in Black Earth, go west on KP 1.1 miles, then south on F 0.25 mile, then west on Fesenfeld Road 0.2 mile to a small parking area south of the road. If the parking lot is occupied, park on the north side of the road.

Public Access
The Prairie is open to the public for hiking throughout the year. Due to the small size of the preserve, hunting is not permitted. Stay on the marked trail (see map).

Volunteer Workdays
Work days are usually the first Saturday of the month, from 9 AM until noon, except in the fall when they are held on Sunday afternoons. For details on work days, contact Kathie Brock at 608-238-5050 or Willis Brown at 608-278-9308 or by email at kmbrock@charter.net or WEBrown3@hotmail.com. More details below.

Boy Scouts helping to pull Queen Anne's lace, an exotic invasive plant, at Black Earth Rettenmund Prairie.

Description and Significance
The site is one of the few remaining examples of a dry-mesic prairie in Wisconsin. In contrast to other prairie preserves in the Driftless Area, this site is on relatively level terrain. It has an outstanding assemblage of plants including several rare and uncommon species. Because of its proximity to Madison, and its easy access, the preserve has great educational value.

Black Earth Rettenmund Prairie is located on a low knob and ridge. It is characterized as dry-mesic with areas ranging from dry to nearly mesic. It harbors a rich flora of over 130 native prairie plant species. It is predominantly a forbs-rich prairie. The forbs are very diverse and include such showy species as pasque flower, lead plant, shooting star, compass plant, blazing star, purple and white prairie clover, wood lily, wood betony, false toadflax, butterfly milkweed, coneflower, black-eyed Susan, sunflowers, asters, and goldenrods. Of significance is the occurrence of pomme-de-prairie (Pediomelum esculentum), white camas lily(Zigadenus glaucus), Carex richardsonii, rough-stemmed false foxglove (Agalinis gattingeri), and a rare aster hybrid. At one time there was Hill's thistle (Cirsium hilli) but this has not been seen recently. Grasses are dominated by big and little blue stem, Indian grass, needle grass, and prairie dropseed. See link for a detailed species list.

Flowers of Black Earth Rettenmund Prairie: Photo gallery

In addition to these rare plants, a threatened butterfly, the regal fritillary (Speyeria idalia) has been observed, as well as striped hairstreak (Satyrium lipdrops).


Lead Plant with Butterfly

Land Use History and Permanent Protection

Based on the original land surveyor records, the presettlement vegetation of the preserve was probably treeless prairie, except in the southwest corner where it graded into oak savanna or open woodland.

The preserve was once part of the William Rettenmund farm but it was probably never plowed. The owner, William Rettenmund, preserved this prairie for over 40 years. Mr. Rettenmund granted conservationists permission to study the prairie and to conduct management activities, including controlled burns. The first plant survey was done in 1969. However, Mr. Rettenmund had observed the marked "decline" in the prairie during his ownership and both he and his wife had a genuine interest in seeing it preserved and managed. It was because of Mr. Rettenmund's deep concern in seeing the prairie preserved that he sold the land to the Nature Conservancy at below market value.

Initial contact with Mr. and Mrs. Rettenmund was made by the State Natural Areas office in 1981, and serious discussions about purchase were made in 1984. At that time, about half of the site had been taken over by shrubs, aspen, and other trees. The property was acquired by the Nature Conservancy in 1986, using funds provided by Madison Audubon Society. Later the same year it was dedicated as a State Natural Area, insuring its continued protection.

Rettenmund Prairie
Many descendants of William and Agnes Rettenmund still live in the area. Members of the family pose next to the State Natural Area sign at the 2005 field trip.

Early Management Activities

Soon after acquisition, restoration work was undertaken by the Nature Conservancy. Controlled burns were carried out at regular intervals. Hand pulling of weeds and cutting of aspen, sumac, honeysuckle, and buckthorn was carried out. Trees along the perimeter of the preserve were cut and the stumps treated with Garlon 4. Cherry trees, honeysuckle, and buckthorn on neighboring land have also been cut with the owners permission. The fence along the neighbor's pasture running east-west was rebuilt by the Nature Conservancy.

In the late 1990s, modest volunteer work parties were carried out, once or twice a year. These involved primarily brush clearing, with herbicide treatment. However, these minimal volunteer activities were insufficient to control woody growth. By the end of the 1990s, brush and tree growth on the south part of the preserve had become excessive, and prairie vegetation was being crowded out. Work on this end of the preserve was initiated again in 2000. Using support from the Savanna Oak Foundation, Inc., private contractors were hired to cut and treat vegetation. Between this work, monthly volunteer work parties, and annual controlled burns, prairie vegetation responded well and thrives.

Management Activities by the Prairie Enthusiasts

Beginning in 2003, management was taken over by the Prairie Enthusiasts under an agreement with the Nature Conservancy. At this time, more intensive restoration work was undertaken, under the guidance of Kathie and Tom Brock and with financial support from the Savanna Oak Foundation, Inc. Ownership (title) to the Prairie was transferred by the Nature Conservancy to the Prairie Enthusiasts in August 2007.

White sweet clover (Melilotus alba) This species remains the most serious problem. Its seeds are able to remain viable in the soil for many years. It is a peculiar characteristic of prescribed burns that fire actually "stimulates" seed germination. Thus, burns without associated sweet clover control will exacerbate the problem. It is probably for this reason that sweet clover has been historically widespread throughout the preserve.

Initially sweet clover infestations were so heavy that they had to be mowed, with hand pulling of any outliers. Prairie Enthusiasts workdays were held throughout the sweet clover season(June-August), with additional weekly workdays on Friday evenings in July. Since 2006 only hand pulling has been needed, but as much as 300 worker-hours (both volunteers and paid contractors) have been needed to control the problem. Summer workdays are scheduled by the Prairie Enthusiasts as needed.

Brush control Extensive work over the past 25 years has reduced the woody vegetation problem to a lower level. The principal problem at present is smooth sumac, and continual work by volunteers and paid employees is effective. The goal is complete eradication of this seriously invasive plant.

Controlled burns An annual controlled burn is carried out by the Prairie Enthusiasts, usually in late March or early April. The preserve has been divided into three burn units (north, saddle, south). The saddle is burned on alternate years, together with either the north or south unit.

Burn Photo

Burn Photo
What the well-dressed burner wears. Two-way radios are used to keep in constant communication with the line boss and the burn boss.

Gateway Prairie Near the entrance to the preserve is a small area that had at one time been plowed and through the years had developed into a field primarily of smooth brome grass (Bromus inermis). When the Prairie Enthusiasts began managing the preserve, restoration of this field began. With careful use of herbicides and planting with native species collected elsewhere on the site, this field has now been turned into a good prairie, and it is managed primarily by fire.

Seed collecting The rich flora of Black Earth Rettenmund Prairie makes seed collecting a delight. The seeds collected are planted in the Gateway Prairie and in areas of the South Unit where brush control had been carried out. Seed collecting is the principal activity in the fall work parties. In addition to regularly scheduled seed collecting days, special days are scheduled as needed.

See link for a detailed species list.

Volunteers assembling to collect seeds on an early fall day.

Volunteers Needed

Workdays are scheduled for the first Saturday morning of the month, throughout the year, except in the fall when they are held on Sunday afternoons. There may also be occasional special nonscheduled days when the need is present. However, modifications of the schedule are made if the Saturday comes on a holiday weekend. An email notification list is maintained, and those interested are invited to submit their email addresses. To get on the list, send an email to Tom Brock at tdbrock@charter.net (Email addresses are never given to others.) Always call the leader before coming to a workday, as weather or other factors may make it necessary to cancel the workday.

Work day leaders:
Kathie Brock: 238-5050 (kmbrock@charter.net)
Willis Brown: 278-9308 (WEBrown3@hotmail.com)

Prescribed burns are another major volunteer activity. Our prescribed burn is usually held at the end of March or early April. Call Tom Brock in late March at 608-238-5050 for information. Volunteers are welcome either as participants or observers.

Black Earth Creek Watershed

Black Earth Rettenmund Prairie is in the watershed of Black Earth Creek, a Class I trout stream that is highly productive and a popular recreation area.
Black Earth Creek has been called one of the top 100 trout streams in the United States. It is a beautiful classic, coldwater, spring-fed trout stream. The Creek is the focus of extensive protective management activities, and is recognized as a fragile but beautiful watercourse. Increasing urbanization of the area west of Madison and Middleton has raised concerns about the fate of Black Earth Creek. The Black Earth Creek Watershed Association is a nonprofit membership-based organization whose goal is the protection of this important trout stream.

Map of the Black Earth Rettenmund Prairie (Download a PDF version)

Species list compiled by R.A. Henderson in the 1990s
  Latin name Common name
1 Acer negundo Box elder
2 Actaea alba White baneberry
3 Allium tricoccum Wild leek
4 Ambrosia artemisiifolia Common ragweed
5 Amorpha canescens Lead-plant
6 Andropogon gerardii Big bluestem
7 Anemone cylindrica Thimbleweed
8 Anemone patens Pasque flower
9 Anemone quinquefolia Wood anemone
10 Anemone virginiana Tall anemone
11 Antennaria neglecta Field pussytoes
12 Antennaria plantaginifolia Plantain-leaved pussytoes
13 Apocynum androsaemifolium Spreading dogbane
14 Apocynum cannabinum Indian hemp
15 Aquilegia canadensis Wild columbine
16 Arabis lyrata Sand cress
17 Arctium minus Common burdock **
18 Arenaria stricta Stiff sandwort
19 Arisaema triphyllum Jack-in-the-pulpit
20 Artemisia caudata Beach wormwood
21 Asclepias syriaca Common milkweed
22 Asclepias tuberosa Butterfly weed
23 Asclepias verticillata Whorled milkweed
24 Asclepias viridiflora Short green milkweed
25 Asparagus officinalis Asparagus **
26 Aster ericoides Heath aster
27 Aster laevis Smooth blue aster
28 Aster oolentangiensis Sky-blue aster
29 Aster pilosus Hairy aster
30 Aster sericeus Silky aster
31 Bouteloua curtipendula Side oats grama
32 Brachyelytrum erectum Long-awned wood grass
33 Bromus inermis Smooth brome **
34 Bromus kalmii Prairie brome
35 Campanula rotundifolia Harebell
36 Capsella bursa-pastoris Shepherds purse **
37 Carduus acanthoides Plumeless thistle **
38 Carex foenea Foen's sedge
39 Carex meadii Mead's sedge
40 Carex richardsonii Richardson's sedge [Concern]
41 Carex umbellata Sedge
42 Caulophyllum thalictroides Blue cohosh
43 Chenopodium album Lamb's quarters **
44 Circaea quadrisulcata Enchanter's nightshade
45 Cirsium discolor Pasture thistle
46 Cirsium hillii Prairie thistle [Threatened]
47 Comandra umbellata False toadflax
48 Convolvulus speium Hedge bindweed ??
49 Convolvulus spithameus Low bindweed
50 Coreopsis palmata Prairie tickseed
51 Cornlus racemosa Gray dogwood
52 Dalea candida White prairie clover
53 Dalea purpureum Purple prairie clover
54 Dodecatheon meadia Shooting star
55 Elytrigia repens Quackgrass
56 Eragrostis spectabilis Purple lovegrass ??
57 Erigeron pulchellus Robin's plantain
58 Erigeron strigosus Daisy fleabane
59 Eryngium yuccifolium Rattlesnake master
60 Euphorbia corollata Flowering spurge
61 Euthamnia graminifolia Grass-leaved goldenrod
62 Fragaria virginiana Wild strawberry
63 Galium spp Bedstraw
64 Gentiana puberulenta Downy gentian
65 Gentianella quinquefolia Stiff gentian
66 Geum triflorum Prairie smoke
67 Hedoma hispida Rough pennyroyal
68 Helianthus grosseserratus Sawtooth sunflower
69 Helianthus laetiflorus rigidus Prairie sunflower
70 Helianthus occidentalis Western sunflower
71 Helianthus strumosus Pale-leaved sunflower
72 Heuchera richardsonii Prairie alum-root
73 Hieracilum longipilum Hairy hawkweed ??
74 Hypoxis hirsuta Yellow star-grass
75 Koeleria macrantha June grass
76 Kuhnia eupatorioides False boneset
77 Lactuca canadensis Wild lettuce
78 Leonurus cardiaca Motherwort **
79 Liatris aspera Rough blazing star
80 Liatris cylindracea Dwarf blazing star
81 Liatris pycnostachya Prairie blazing star
82 Lilium philadelphicum andinum Prairie lily
83 Lithospermum canescens Hoary puccoon
84 Lithospermum incisum Fringed puccoon
85 Lobelia spicata Pale spiked lobelia
86 Lonicera tatarica Tartarian honeysuckle **
87 Lychnis alba White campion **
88 Medicago sativa Alfalfa **
89 Melilotus alba White sweet clover **
90 Monarda fistulosa Wild bergamot
91 Muhlenbergia racemosa Upland wild timothy
92 Oenothera biennis Common evening-primrose
93 Oenothera rhombipetala Sand primrose ??
94 Orobanche uniflora One-flowered broom-rape [Concern]
95 Osmorhiza longistylis Smooth sweet cicely
96 Oxalis stricta Tall wood-sorrel
97 Oxalis violacea Violet wood-sorrel
98 Panicum depauperatum Starved panic-grass ??
99 Panicum leibergii Prairie panic-grass
100 Panicum oligosanthes Few-flowered panic-grass
101 Panicum perlongum Long-stalked panic-grass
102 Panicum praecocius Early panic-grass
103 Parthenocissus sp Creeper
104 Pastinaca sativa Wild parsnip **
105 Pedicularis canadensis Wood betony
106 Pediomelum esculentum Pomme-de-prairie [Concern]
107 Phalaris arundinacea Reed canary-grass
108 Phlox pilosa Prairie phlox
109 Physalis heterophylla Clammy ground-cherry
110 Physalis virginiana Lance-leaved ground-cherry
111 Plantago major Common plantain **
112 Poa compressa Canada bluegrass
113 Poa pratensis Kentucky bluegrass **
114 Podophyllum peltatum May-apple
115 Polygala senega Seneca snakeroot
116 Polygonatum biflorum Smooth Solomon's seal
117 Polygonum convolvulus Black bindweed **
118 Potentilla arguta Prairie cinquefoil
119 Prenanthes racemosa Glaucous white lettuce
120 Prunus americana Wild plum
121 Prunus pensylvanica Pin cherry
122 Prunus pumila Sand cherry
123 Prunus serotina Wild black cherry
124 Pycnanthemum virginianum Common mountain mint
125 Pyrus ioensis Iowa crab
126 Ranunculus abortivus Small-flowered buttercup
127 Ratibida pinnata Yellow coneflower
128 Rhamnus cathartica Common buckthorn **
129 Rhus glabra Smooth sumac
130 Rosa carolina Pasture rose ??
131 Rosa sp. Rose
132 Rubus occidentalis Black raspberry
133 Rubus spp Raspberry, blackberry
134 Rudbeckia hirta Black-eyed Susan
135 Salix humilis Prairie willow
136 Schizachyrium scoparium Little bluestem
137 Scrophularia lanceolata Early figwort
138 Silphium integrifolium Rosinweed
139 Silphium laciniatum Compass plant
140 Sisyrinchium campestre Prairie blue-eyed grass
141 Smilacina racemosa False Solomon's seal
142 Smilax lasioneura Common carrion flower
143 Solanum dulcamara Deadly nightshade ??
144 Solanum nigrum Black nightshade
145 Solidago canadensis Common goldenrod
146 Solidago gigantea Late goldenrod
147 Solidago juncea Early goldenrod
148 Solidago missouriensis Missouri goldenrod
149 Solidago nemoralis Gray goldenrod
150 Solidago ptarmicoides Stiff aster
151 Solidago rigida Stiff goldenrod
152 Solidago speciosa Showy goldenrod
153 Sorghastrum nutans Indian grass
154 Spiraea alba Meadowsweet
155 Spiranthes cernua Nodding ladies' tresses
156 Sporobolus asper Rough dropseed
157 Sporobolus heterolepis Prairie dropseed
158 Stipa spartea Needle grass
159 Taraxacum officinale Common dandelion **
160 Thalictrum dasycarpum Purple meadow-rue
161 Toxicodendron radicans Poison ivy
162 Tradescantia ohiensis Common spiderwort
163 Tragopogon dubius Sand goat's beard **
164 Trifolium pratense Red clover **
165 Trillium grandiflorum Large-flowered trillium
166 Triosteum perfoliatum Tinker's weed
167 Uvularia grandiflora Bellwort
168 Verbascum thapsus Common mullein **
169 Verbena stricta Hoary vervain
170 Veronicastrum virginicum Culver's root
171 Viola palmata Wood violet
172 Viola pedata Bird's foot violet
173 Viola pedatifida Prairie violet
174 Vitis riparia Riverbank grape
175 Xanthoxylum americanum Prickly ash
176 Zigadenus elegans glaucus White camas lily
177 Zizia aptera Heart-leaved golden alexander
  ** Nonnative  


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