Switchgrass has been well-researched in Ohio (Van Keuren, 1985). Switchgrass should be grazed prior to heading (about May 25) for good animal acceptance and performance; grazing should be completed by July 1. If regrowth is stimulated, grazing may remain good for two or three weeks or regrowth can be grazed later in the season.
If lime is needed, apply it before the soil is tilled. Apply phosphorus and potassium according to soil-test recommendations. Do not apply nitrogen fertilizer at seeding. Nitrogen would stimulate weed competition. Some nitrogen can be applied about July after the grasses have started growing. Till soil in the spring at least a month before grasses are to be planted. A light surface tillage at seeding time will kill newly emerged weeds.
The best time to seed warm-season grasses in southern Ohio is May or early June. These grasses need warm soils to speed up germination and establishment. Seedings made in late June or early July can be successful if good soil moisture is present at seeding time.
Switchgrass can be seeded with a conventional drill into a prepared seed bed or with a no-till drill into killed sod. Drilling is recommended because it requires less seed than broadcasting and is usually more successful. Drill at 8-10 lbs. per acre pure live seed (% germination + % dormant x % pure seed) or 10-15 lbs. per acre via broadcasting. Pure live seed per acre is important, because average-quality commercial seed of native grasses tends to have lower germination than the seed of cool-season grasses. Drills are available that are specially equipped to handle this type of seed. Using such drills is the best option if they are available. Check with Ohio State University Extension or the Natural Resources Conservation Service for availability of these drills.
It is also possible to use hulled seed of some species in the legume box of a standard drill. Drop the seed on the soil surface and press it in with the packer wheels. Small, light seed may be mixed with ground corn if more bulk is needed for good spreading. Adjust the drills to place the seed one-quarter of an inch deep.
You can also mix the seed with fertilizer and seed it with a gravity-flow fertilizer spreader. First seed the field in one direction and then again in a perpendicular direction to ensure uniform coverage. Then firm the soil with a corrugated roller (cultipacker). Avoid using spinner type fertilizer equipment if possible.
Mowing is needed during the first summer to control weeds. Mow in July, clipping high enough to avoid mowing off the switchgrass seedlings (about six inches). It may be necessary to clip twice during the first summer, but do not clip the field after the end of August. Do not graze during the first year to avoid damaging the stand.
The native grasses germinate and develop more slowly than the cool season perennial grasses. What may appear to be an unsatisfactory stand of a native grass may actually be a good stand. Wait until the following summer before abandoning the seeding.
Switchgrass is suited to rotational grazing systems. Begin grazing at 12-18 inches and don't graze shorter than six inches. Stop grazing mid-September. Do not graze warm-season grasses until after seed maturity the first year.
The warm-season grasses work well in systems containing cool-season grasses and legumes in other fields. An example: