UGA Forage Extension Team

Considerations for Seeding Warm Season Perennials

By Jeremy Kichler
Colquitt County CEC

 This time of year, County Agents get questions about establishing warm season perennial forages from seed. Forage establishment can be expensive, especially if you have to do it twice.  Let’s discuss some things that ensure successful perennial forage establishment on the first try.

  • Fertility. Soil sampling should be done before a few months before attempting establishment. If the producer has to address soil pH issues then they need to be addressed in a timely manner. According to Southern Forges, if the area has a low soil pH then it may be advised to apply one-half of the recommended lime a few months in advance of planting and then till the field. After the tillage is completed then apply the reminder of the lime that is required. This helps distributes the lime throughout the soil profile.
  • Planting Date. Planting date plays an important role in forage establishment. Weather can delay establishment dates, which could be the difference between success and failure. The best time to plant bahiagrass is in the early spring on upland soils or in late spring on low, moist soils. Plantings made later in the summer can be successful but weed competition can be a problem. Seeded bermudagrass and bahiagrass can begin once soil temperatures reach and are expected to stay at 60 degrees.
  • Seeding Rate. Seeding cost is often a big psychological barrier in establishing forages. In the grand scheme of things, the cost of seed is trivial compared to the other costs of establishment, dealing with gaps in the stand during grow-in, and re-establishment. Seeding rate can be influenced by seeding method and seed quality. If broadcasting, seeding rates need to be increased by 20% compared to using a drill. Seeding rate recommendations are based on the assumption of high germination rates.   If germination rates or vigor is questionable then increase seeding rates accordingly. In Table 1, seeding rates are shown for three perennial forage crops in Georgia.

Table 1: Seeding Rates for Three Warm-Season Perennial Forage Crops in Georgia

Forage Seeding Rate in Pounds Per Acre Seeding Depth in Inches
Bermudagrass (Hulled) 5-8 0-1/4
Bahiagrass 12-15 ¼ – 1/2
Sericea Lespedeza 15-20 ¼ -1/2
  •  Seedbed Preparation. The seedbed should be relatively firm prior to planting. This is especially important for small seeded forages such as bermudagrass and bahiagrass. Firm the planting site with a cultipacker before seed is planted.   If your planting site has ridges or depressions then they should be smoothed out, as they encourage moisture loss and may challenge seed placement.  Footprints left by an average person on a properly prepared seedbed should not be more than ¼ inch deep.
  • Seeding the crop!! This is the hard part. A cultipacker seeder or a drill with a small seed attachment is helpful for seeding small seeded forage crops.   Drills can be challenging because of the chance of planting too deep. A good rule of thumb is that seed should be planted no deeper than eight times the thickness of the seed. If the drill places the seed too deep even after adjustment, one may need to disconnect the tubes from the small seed box from where they enter the drill’s shoes and secure the drop tubes behind the shoes or in front of the press wheels with wires or other means. This allows the small seed to be metered out on the soil surface and pressed down into the soil by the press wheels.

An issue of ensuring sufficient seed to soil contact may challenge producers if they attempt to use the broadcast method of establishment. Conventional-till seedbeds should be firmed with a cultipacker before seed is broadcasted. Broadcast seeding on a prepared seedbed should be followed with adequate firming of the seedbed with a cultipacker.  This would ensure good seed to soil contact.

If you are using a spinner seeder to broadcast small seeded forages keep in mind that the low seeding rates might cause some challenges. Seed can be mixed with coarse sand or some other inert material that is similar in size and weight.  Large volumes of smaller seeds should not be mixed with larger seeds in the hopper or seed boxes because the smaller seeds could settle to the bottom.

Once you have seeded your forage crop, table 2 below shows a check list of potential issues that producers could face.

Table 2. A Checklist of Potential Problems during Forage Establishment.  

Failure to Germinate Seed Germination but seedling did not emerge from soil Seedlings emerged but did not survive
Dry Seed Bed

Non-viable Seed

Hard or dormant seed

Unfavorable temperature

Herbicide Residue

Waterlogged Soil

Planted Too Deep

Soil crusted at surface

Poor seedling vigor

Insects or diseases

Extreme temperature – Hot or cold

Soil too acid or low fertility

Insects or diseases

Drought

Weeds

No legume nodulation

Winterkill

Heaving from freezing and     thawing soil

Sandblasting of seedlings

Grazing too early.

**Southern Forages, Fourth Edition…