Save Our Savannas

Which is worse?

buckthorn choked savanna

This?  Buckthorn-choked savanna?

Or this?

A lawn grown under the oak trees, mowed, fertilized, and watered on a regular basis.

oak savanna bad example

Well, this one certainly looks better, carefully kept, all neat and tidy.

I hope you already know the answer.  Actually, they are both terrible.  Both sites guarantee the demise of our oak trees, because neither situation allows acorns to sprout and grow into new trees.

In the top picture, shade from the buckthorn prevents the acorns that fall from the oak trees from sprouting;  In the lower picture herbicides and the lawn mower prevent germination of acorns and wild flowers.

Buckthorn and other invasive shrubs leaf out early and abscise their leaves late, thereby allowing very little light to reach the ground.  All this shade has kept oak trees from sprouting and reproducing, guaranteeing their eventual demise.   The dense cover also keeps wildflowers and sedges from germinating and growing on the woodland floor. Without a herbaceous carpet, the soil will soon erode away.  In addition, trees rely on the dense fibrous roots of sedges  to keep them adequately hydrated.

Brenda, fellow Wild Ones member, was faced with 6 acres of a buckthorn, garlic mustard  infested  Oak Savanna many years ago.

In her words:

“My property is a rolling 6 acre Oak savanna.  It primarily contains mature White Oak and Red Oak with some Shagbark Hickory, Black Walnut, various hawthorn and cherry.  I have worked actively for the last 20 years to clear a disturbed woodland thick with cherry trees and honeysuckle, with the only flower present seeming to be garlic mustard, to open the forest floor to sunlight. “   Brenda cut down and then  herbicided the stumps of Buckthorn and Honeysuckle,.

“It is now rich in a diverse blend of native plants – most of which volunteered when given sunshine.  The woods are host to many butterflies, dragonflies, bees, and various insects.  The birds visiting include rose breasted grosbeak, indigo bunting, orioles, hummingbird, scarlet tanager and woodpeckers.”

brenda savanna wild geranium

A Northern Kane County Wild Ones walk through Brenda’s savanna, last May with Shooting Star, Wild Geranium, various Trillium, Blue-eyed Grass, Sweet Cicely, and others in bloom.

Brenda front yardThe savanna wraps around the whole house.

burn 1 brenda
In addition to clearing and herbiciding, a controlled burn keeps the invasive plants from coming back.  The burn also fertilizes the plants, putting back the nutrients into the soil.

Valerie, Wild Ones member and Kane County Forest Preserve Educator had the opposite problem.  When she purchased her wooded, 2-acre lot in 1998, it was a monoculture of even-aged White Oak in a sea of manicured turf grass, similar to the 2nd photo above.

Valerie’s goal was to turn the area into what it had been before–a biologically diverse oak-hickory woodland.  Her first step was to mow the turf grass as low as possible, then over-seed it with seeds from savanna grasses, sedges, and forbs.  Acorns, buried by squirrels began to sprout and grow into trees, as will all nut trees–Shagbark Hickory (Carya ovata), Black Walnut (Juglans nigra), Butternut (Juglans cinerea), and American Hazelnut  (Corylus americana).  With weeding, some herbiciding, more seeding, and controlled burns over the years, she has been successful.

Valerie w: purple coneflower

Valerie’s savanna last August with Purple Coneflower and Joe Pye Weed in bloom.

We think of Purple Coneflower (Echinacea purpurea) as a prairie plant, but in nature it is more often found in Bur Oak savannas.  Joe Pye Weed is a denizen of woodlands, as well, and prospers especially well in woods that  have been burned.

valerie purple giant hyssop

White Oak with Purple Giant Hyssop (Agastache scrophulariaefolia).  Purple Giant Hyssop isn’t, however, purple–at it’s best, it is very pale lavender.  It has  great architectural presence: the square stems grow up to 8‘ tall, clothed with bold opposite leaves and topped with dense spikes  of tubular flowers from mid-July to mid-September.  The numerous stamens that protrude from each blossom give the spike a fringed appearance.  Butterflies love it.

In nature, it is found in open woods, especially at the edge of clearings.

Valerie savanna joe pye

Another deeper section of the woods, with more Joe Pye Weed.

Project Quercus of McHenry County Land Conservancy says that “our beloved oak trees are under stress, and if nothing changes, they may be largely gone from the local landscape within 20 years.”  20 years!

What to do?  Let’s follow the example of the two property owners above.

Late fall and winter are the perfect time to cut out the brush that is choking our savannas and woodlands.  Cut the shrubs to the ground and paint the stump with Brush-Be-Gone or Garlon.  If you don’t want to use chemicals, you can cover the stump with black plastic and, given time, it will die.  Or you can girdle the tree trunk by removing a section of the bark encircling the tree.  Best time to do this is early spring before the tree leafs out.

If you have scattered oak trees situated in turf, interseeding is the best way to turn it into a savanna.  Either mow or burn the existing turf grass, then sow seed either in spring or fall.  Plant grasses and sedges such as Penn Sedge (Carex pensylvanica), Grass Sedge (C. jamesii), Common Wood Sedge (C. blanda),  Hairy Wood Sedge (C. hirtifolia), Woodland Brome (Bromus pubescens),  Bottlebrush Grass (Hystrix patula); add forbs such as Wild Geranium (Geranium maculatum), Virginia Waterleaf (Hydrophyllum virginianum), False Solomon’s Seal (Smilacina racemosa), Short’s Aster (Aster shortii), and Zig-zag Goldenrod (Solidago flexicaulis).

Set the mower high and mow the turf grass when necessary to keep it from over-shading the new emerging plants.

This is just an outline–I suggest you read The Tallgrass Restoration Handbook for Prairies, Savanna, and Woodlands by Stephen Packard and Cornelia F. Mutel.

Let this be the year.

 

 

 

, , ,

9 Responses to Save Our Savannas

  1. Mary Alice Masonick November 16, 2014 at 5:57 pm #

    Love oak savannas!

    Our neighborhood, Wildwood Valley, is an oak savanna that dates back to presettlement times. One bur oak may be approaching 300 years old, judging by its measured circumference.

    In our neighborhood, we’ve planted young oaks in all four cul-de-sacs. In our yard, which is relatively low and wet, we’ve planted bur oak and swamp white oak saplings. They are all thriving!

    • Pat Hill November 17, 2014 at 10:17 am #

      I’ve seen what you have done, Mary Alice. Keep up the good work!

  2. mike weis November 16, 2014 at 6:21 pm #

    fantastic!! I’m reading an incredible book right now by Joel Greenberg called A Natural History of the Chicago Region and there’s a great chapter on Oak Savannas and woodlands. Are you familiar with this book?

    • Pat Hill November 17, 2014 at 10:21 am #

      Yes, Mike. A Natural History of the Chicago Region is one of my all time favorite books and I highly recommend it to everyone. Would make a great Christmas gift. Our area has suffered irreplaceable losses, but hopefully, we’ll hold onto what we still have.

  3. Mark Allen November 17, 2014 at 7:05 am #

    Batavia’s Fermi Lab has 40 yrs of restoration of savanna’s and prairies. Each week are opportunities to assist with seed collection, sorting and application of our preciousness resource. Witnessing 500 acres go up in smoke is a treat too. As a federal institution lots of research and publications on birds, butterflies, mammals, grasses,and sedge’s.

    http://www.fermilabnaturalareas.org/

    • Pat Hill November 17, 2014 at 10:40 am #

      I was there many years ago and I highly recommend that everyone visit there. Robert Betz, PhD, the person who made it happen, has also written a book, called The Prairie of the Illinois Country, published privately, posthumously, in 2011. Getting involved in group restorations not only helps the natural world but one makes a lot of triendships, as well.

  4. Pat Sullivan-Schroyer November 17, 2014 at 6:13 pm #

    Wow! What a great essay on restoring savannahs giving us a very simple way to approach a very significant effort. Plus, now I know why purple joe pey weed is absolutely thriving in our front yard—the periodic burns we do. Wish everyone would plant an oak in their yard!

  5. Suzanne Massion November 21, 2014 at 7:51 pm #

    So much valuable information, Pat. Brenda’s success is encouraging to us. Our biggest challenge right now are Buck thorns, full grown, saplings, and sprouts. Of course there seems to be a never-ending seed bed of these trees in our woods. We haven’t been able to burn through portions of the savannah in several years (wet springs). A burn would help. The best oak tree planters? Squirrels! Their efforts have resulted in the replacement oaks we see at the woods’ edge. These young oaks are thriving.

    • PatHill November 23, 2014 at 12:47 pm #

      Have you ever thought of fall burning? Here’s a paper by Jerry Wilhelm on the subject:

      Timberhill Savanna—Assessment of Landscape Management, by Gerould Wilhelm and Laura Rericha, 2007

Leave a Reply

*

Powered by WordPress. Designed by WooThemes