August provides a window of opportunity to establish a perennial forage stand. The goal should be to get the stand seeded by the end of August. This recommendation is based on average frost dates and the time needed for forage plants to develop a root system and carbohydrate reserves that will allow it to overwinter. For example, alfalfa plants must reach the contractile growth stage, where the growing point is pulled below the soil surface, to overwinter successfully. This takes 8-10 weeks after emergence. Clover plants need to have a crown formed, and grasses should be at least in the tillering stage of development before the onset of winter.
When we have extended warm falls, forage stands have been successfully established with later planting dates, however, planting date research in Pennsylvania in the mid-1990’s showed increased dry matter forage yield loss the year after seeding for alfalfa, red clover and birdsfoot trefoil for each day planted after the recommended last planting date. Grasses were less affected by later planting dates than legumes.
In a no-till situation, minimize competition from existing weeds by applying a burndown application of glyphosate before planting. Using no-till when herbicide-resistant weeds are present creates a very difficult situation with no effective control options, so tillage is probably a better choice in those situations. Post-emergence herbicide options exist for alfalfa. Consult the 2015 Ohio and Indiana Weed Control Guide and always read the specific product label for guidelines on timing and rates before applying any product.
If tillage is used to prepare the soil for planting, a firm seedbed is needed to ensure good seed-to-soil contact. Soil should be firm enough for a footprint to sink no deeper than one-half inch. The recommended seeding depth for forages is one-quarter to one-half inch deep. It is better to err on the side of planting shallow rather than too deep.
Finally give consideration to making sure soil pH and soil fertility levels are adequate to permit good establishment, select high quality seed, use new, improved forage genetics and take time to calibrate the planter. For more information about late summer forage seeding, contact the Wayne County Extension office at 330-264-8722.