Prepare, plant and water All native seed—individual species or mixes--establishes best if planted on areas that have no green vegetation at time of seeding. For eradication of existing vegetation, herbiciding with glyphosate (e.g., "Roundup") gives dependable results, especially if two applications are used. The area should have four to six inches of active growth so spring and fall applications are best. For tougher weeds, or areas near water, contact your local Farm Services agent for product recommendations and application rates. Tilling the soil is not advised on small sites of three acres or less since soil tilling can stir up dormant weed seeds and create extra work in the maintenance phase before your native plants are established. Larger acreages can be approached as an agricultural site with tilling, herbiciding, planting of a cover crop or a combination of strategies. After herbiciding, dead thatch should be burned or mowed and raked so the seed will be able to make contact with the soil. Pressing the seeds into the surface is acceptable, but covering them will reduce germination rate. Firm the seedbed by rolling or packing the surface. The best time to apply native grass seed is early spring until mid-May or early June. Native grass seeds germinate best when soil temperatures warm to at least 65 degrees F. Early spring is preferred to take advantage of spring rains. Plant debearded native grass seed with a no-till drill. When the grass is about an inch tall, decrease the frequency and increase the depth of watering. You can stop adding water once the grass is established.
Cover Crops and Soil Amendments If you're ready to take action before the proper time to plant your native seed, or the site's soil is depleted, plant a cover crop of inexpensive cereal rye grain or oats. This is entirely different than rye grass for lawns. Traditionally, farmers used cover crops before chemical fertilizers came along. These economical, non-invasive crops offer erosion control and, the following spring, can be plowed under to add nutrients and rebuild soil which has been depleted. Using cover crops to build soil takes some extra time, but is more effective and lasting than adding chemical fertilizers or mycorrhizal inoculants. Sow your cover crop at 60-95 pounds per acre between July 15 and September 5. A hard fall freeze will kill the oats before they set seed. Hand seed your native seed mix into the standing oats in late October. Do not rake or drag the seed into the soil. Frost action will help the native seed work into the soil. The dead oat plants will provide mulch that both aids spring germination and helps prevent soil erosion. Areas larger than one acre can be planted into the standing oats using a seed drill with a no-till attachment.
Weedlings, Seedlings and Maintenance Native grasses planted from seed spend the first year or two sinking their extensive root systems into the soil. For this reason, you might not see a lot of top growth right away when starting from seed. Be patient. These large root systems are what sustain the plants through drought and harsh winters. The best maintenance of your native planted areas is to burn the old top growth every year or two. To encourage native wildflowers, burn plots in fall; to encourage native grasses, burn plots in early spring, around late February to early March. It may be two or three years before the tracts have adequate fuel to have a productive burn. Burning helps control invasion of weeds or unwanted woody vegetation and also releases valuable nitrogen into the soil. If you cannot, or choose not to burn, the areas can be mowed on the same schedule. During your second growing season, one mowing at a height of six to 12 inches in late spring or early summer will control weeds and should be the last weed control mowing needed. The mowed refuse must either be removed or adequately mulched to prevent the refuse from smothering new seedlings. Mowing also helps reduce the possibility of accidental grass fires. If the site has any recurring problem weeds, hand weeding of the wildflower plots will make a big difference. Other control options are clipping weeds near the ground with pruning shears, carefully spot-applying herbicide to individual weeds or a controlled burn.