July 19, 2023 | Vol. 15 : No. 7-B

Seed an ‘Annual’ Pasture Within a ‘Perennial’ Pasture

Add oats and brassicas to stands that are thin.

Producers looking for ways to grow forages during drought might consider planting an “annual pasture within a perennial pasture,” says University of Missouri Extension State Forage Specialist Harley Naumann. Naumann says this is a good year to add cool-season annual grass seed to perennial pastures. Cool-season grasses can extend the growing season, provide excellent nutritive value and complement thin pastures.

While he might not recommend this strategy in years with normal precipitation, back-to-back drought years in most of the state led Naumann to suggest new ways to grow grass. He notes that all suggestions come with the caveat that it takes rain to bring seeds out of dormancy.

“We can add annuals to perennial pastures this year because our perennial base is so thin right now,” he says. By drilling or broadcasting cool-season grasses into existing perennial stands, producers will get a much-needed pop of vigorous growth.

Naumann says spring oats are ideal for producing quick growth. It may sound confusing, he says, but you seed spring oats in late summer to get fall forages. Seeding can begin in late July to early August and, at times, even as late as September.

The key is to have seed on hand and ready to go into the ground when rain is in the forecast.

Naumann recommends late-maturing seed varieties of spring oats, which produce quality forage throughout fall and into winter.

Like any forage, the longer you let it grow without grazing it, the more forage produced. Patience rewards the producer with more tonnage. A Wisconsin study showed that yield quadrupled when harvest was delayed from September to November on August-planted oats.

As a rule of thumb, allow 60 days between planting and grazing, Naumann says. This means delaying grazing until October or early November on pastures seeded in late July to early August.

Brassicas such as turnip, radish and rapeseed can be drilled, or broadcast and harrowed in, as a companion forage to oats before anticipated rainfall. Brassica seeds are small and easily broadcast. Broadcast 2-5 pounds (lb.) of seed per acre for an expected 3-5 tons of forage per acre, says Naumann.

He urges caution when grazing brassicas. They can have low mineral content, low fiber and high nitrate levels. They also can cause bloat, among other issues. Supplement brassicas with minerals and dilute with other forages to mitigate these downsides.

Naumann says another option in drought is to add cool-season small grains like cereal rye, wheat, triticale and barley to pasture stands that are thin in September to October.

Small grains won’t provide feed until late winter to early spring. Grazing these forages can begin in the southern part of the state as early as late February and by mid-March in the northern part of Missouri.

“The value of these annuals is they give you forage before fescue is ready to be grazed, and they will complement thin fescue yield,” says Naumann.

Editor’s note: News release provided by University of Missouri. For more drought resources, visit