Tom's Blog

Monday, July 14, 2014

Turning an abandoned house site into prairie

The farm house near our cabin was burned down by a former landowner. The land under and around the house was ignored until we removed the debris about 15 years ago. By the time we started restoration work here, the land had become a major weed patch. Wherever there weren’t conventional weeds, day lilies had run amok.

Once we started, it took us 12 years to eradicate all the bad plants and to get a lush, diverse prairie established. Although not a Superfund site, the legacy of the house structure undoubtedly made this restoration difficult. Our experiences might be useful for those trying to establish natural areas in urban areas.

Before planting, the herbaceous vegetation and the brush were treated with 2-3% glyphosate (foliar back-pack sprayers) and the dead vegetation burned off. In November 2002 the site was planted with a prairie mix suitable for dry-mesic to mesic conditions.

Although prairie plants became established, there still remained a lot of undesirable vegetation. The principal undesirables were day lilies, brambles (mainly black raspberries) and sumac, with occasional honeysuckle.

We got started with serious eradication work in 2006 and finally, in 2014, we seem to be finished. Although this seems a long time, I suspect it is typical of what one can expect when restoring such a very bad site. Since it was a small site (less than 1 acre), complete canvassing the site could be done, ensuring that no invasive plant was missed.

We burn this site every year, usually in mid- to late-March. As soon as the invaders started to appear they were sprayed, several times during the early growing season. The goal was to have all the invaders sprayed before prairie vegetation got too big. Further details are given below.

Day lilies. There were lots of these, and they had spread all through the site, as well as into other areas nearby. Because this is a monocot, glyphosate was used. Fortunately, these plants show early so we could kill them before “good” species got too big. However, day lilies have a deep, persistent rhizome system, making them difficult to kill. We discovered that for success we needed to use a high concentration of glyphosate (8%).

Brambles. These generally don’t begin to appear until early May, but continue to show throughout most of the month. We attempted to catch these at the rosette stage, using a foliar spray of 3-4% Garlon 3A. Any plants that were missed in the May sprayings were allowed to grow until they were several feet tall (so we could sure we weren’t missing any), and then killed by basal bark treatment with 20% Garlon 4 in oil. Complete eradication took so long presumably because of the extensive rhizome system.

Sumac. This shrub also has an extensive rhizome system, but has the additional problem that it root suckers extensively. Thus, after the above-ground plants are killed with Garlon, root suckers form and will continue to appear until late summer. Those shoots appearing in early June can be sprayed with Garlon but those missed or arising later are best allowed to wait until they are large enough so that they can be treated by Garlon 4 basal bark. Like brambles, eradication of sumac took quite a few years.

Even though the prairie plants had become well established over the first 3-5 years after seeding, it took at least 10 years to eradicate day lilies, brambles, and sumac.

Ragweed and other annuals were hand pulled before flowering, generally by mid-summer.

Because this site was small and was near the cabin, it could be monitored easily, which was a real advantage.

The photo shows what the site looks like now.

Part of the Cabin Prairie that was planted on the old house site.
A diverse flora has been established, including both forbs and grasses


Blogger Kari Cedergren said...

Hi Tom,
I was wondering if I could talk to you about restoration of oak savannah? 320-267-5159
Kind Regards,
Kari Cedergren
Benton County Master Gardener

July 23, 2014 at 7:24 PM  

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