Cover Crop Planting in Full Swing

Posted: September 2, 2014

The window for fall cover crop establishment depends on where you live. We are rapidly moving beyond that window for some cover crops.

Slow development of corn and soybeans is delaying harvest 7-10 days in much of Pennsylvania and this is creating some challenges with timely planting of cover crops. We are only 20 days from the average first frost in northern and 50 days from first frost in southern PA. However, some winter-killed cool-season cover crops such as oats and forage radish will grow until the mercury dips below 17F, so we still have some time to grow provided adequate soil fertility is present. To expect a fall harvest of oats after corn silage, however, is probably too much to ask at this point. Some other cover crops survive the winter if they store enough reserves before they go into winter dormancy. Although a tad bit late, oats and radish can still be planted this week in the southern portion of the state, and there is still opportunity to plant annual ryegrass, crimson clover, hairy vetch and rape until September 15 in that region. In central Pennsylvania, oats and forage radish are questionable and this is about the last week to plant annual ryegrass, crimson clover, hairy vetch and rape there. In northern Pennsylvania, the window of opportunity for annual ryegrass, crimson clover, rape, barley, spring oats and forage radish has already closed. Our traditional workhorses, cereal rye and wheat can still be planted without danger of winterkill in all of the state, while barley can be planted until mid-September and early October in the central and southern sections of the state, respectively. If using mixtures, these guidelines can be used to decide which species to include. As a reminder, the following table provides planting deadline recommendations:

Table. General cover crop planting deadlines based on growing region. These dates will vary somewhat from year to year depending on late fall temperatures and the severity of the winter.

Sole seeding rate (lb/A) Northern PA Central PA Southeastern PA
Annual ryegrass 20 15-Aug 1-Sep 15-Sep
Crimson clover 12 Not recommended 1-Sep 15-Sep
Hairy vetch 20 15-Aug 1-Sep 15-Sep
Rape 10 15-Aug 1-Sep 15-Sep
Barley 120 15-Aug 15-Sep 1-Oct
Wheat 120 15-Sep 1-Oct 15-Oct
Triticale 120 1-Oct 1-Oct 15-Oct
Cereal rye 112 1-Oct 1-Oct 15-Oct
Spring oats* 100 1-Aug 15-Aug 1-Sep
Forage radish* 10 1-Aug 15-Aug 1-Sep
* Will winterkill throughout Pennsylvania

Contact Information

Sjoerd Willem Duiker
  • Associate Professor of Soil Management and Applied Soil Physics
Phone: 814-863-7637