Johnsongrass (Sorghum halepense), is an exotic (non-native and invasive) grass which can kill livestock if eaten just after a freeze.
There are some real important do’s and don’ts about preparing the land. And they are d—- important to your project. There’s so much more to be said on this topic than we can give you here, but we thought we should get this bit to you in time for you to act on it. We’ll just have to cover equipment later. It’s important, also. We do cover several important issues. The editor had a long talk with Arnold Davis, retired Soil Conservation Service Plant Materials Center Director and prairie restorationist, and also excerpted sections from an article he had previously written. This information is important. Take it to heart.
For the real lowdown on this crucial preparation for your restoration project, you’ve really just got to call the experts. Bill Neiman (214-539-9883) does this for a living and has experience you will wish to benefit from. Call and get a consultation. It is easy to blow your project and waste your financial investment of seed and equipment ... and time. If this sounds like a commercial, too bad. So, you want to restore a prairie? Here’s a bit of what you’re in for.
Don’t Disc Deeply (unless you’ve got Johnsongrass). ” A common mistake is to till the soil too deeply and leave it loose and uncompacted. The correct procedure is to till the seedbed to a depth of 2-3 inches, remove the debris left from construction and trashy weeds, and smooth and let settle or firm with a packer.
“Try to complete the final grading well in advance of the projected seeding date; then the soil will have had time to mellow and weather out…. Many of the common weed seeds geminate March through May…it sometimes pays to destroy the first weed sprouts with a shallow tillage before planting .... This often saves a lot of work and problems later.”
OK, So You’ve Got Johnsongrass. Here’s what you can do. Arnold Davis says till it deeply 10 to 15 inches down to expose and dry the roots in the early summer. Use a shovel to figure out how deeply on your site. there will be some regrowth after the fall rains in September from rhizomes which which survived the first tilling. If you’ve no great aversion to pesticides, this is a great time to hit ‘em with Round-up. Hit ‘em again with a tilling after the first freeze. (As you can see, we are serious about the need to get this stuff out of your prairie before you plant. This quality of your prairie depends on your taking this seriously too.) Now leave the land alone till February. Now, you may proceed safely with your final smoothing of the seedbed by leveling it with a harrow. This will get rid of those winter weeds.
If you still see Johnson grass resprouting in the spring, use an herbicide then. If you don’t take these steps - at least the tillages - you will live with Johnsongrass dominating your prairie for at least a few years. It rather takes the fun out of it.
You’ve got K-R Bluestem? Plow deeply enough to turn the roots up in the early summer. Do everything you can in the early summer to kill those roots. If you get fall germination of K-R, till your land two inches deep. Don’t ever go below this two inch depth. If you go more deeply, you’ll just be bringing up more seed. The minute you see any germination at all, use a spring tooth harrow or a section harrow, but never below two inches.
Bank on at least one more germination occurring. Get them too. You won’t be planting your prairie until May. But live with that fact. Get the seed to germinate, then kill them with tillage or herbicide. This exotic seeds well, is aggressive, and spreads under conditions of grazing and mowing.
No Exotics to Hassle with? You May Go to Winter Cover Crops
“If preparation of the seeded area is completed in the late summer or fall, a temporary cover of cereal rye (not ryegrass) or wheat can be established to control erosion during winter. This temporary cover crop will promote seedbed settling and to some extent will retard winter weed growth. Plant the cereal small grain at double the usual seeding rate for grain production: use about two bushels per acre.
“Excessive growth of the cover crop should be controlled, if needed, by mowing during the winter months. Start mowing or shredding at about a four inch height and lower the blade at each subsequent mowing until the last cutting, about mid-March, is at ground level. If this cover crop is not killed by this time, you should apply an herbicide that will destroy the existing vegetation. Be careful not to use an herbicide that has a pre-emergent grass-killing action, for that would harm the seedlings later.”