Seeding Depth - Considerations for Success

    Soil variability can place new seedlings in an uphill battle. It’s critical that growers do everything possible to achieve proper planting depth. Here are 5 reminders to ensure proper seeding depth and maximum germination:

       
    1
    Seeds of different sizes normally require different seeding depths. Most forage grass and legume seeds are smaller, and require a shallow depth of ¼” - ½”. Traditionally, seeding depth should be ~3-5 times the diameter of the seeds being sown.
     
    2
    Soil texture impacts proper seeding depth (i.e. sandier soils tolerate deeper seed placement). As a rule, the same forage seed planted at 3/8” on clay soils should be placed between ½” to 5/8” on sand. Emergence declines significantly if forage seeds are planted too deep on clay, and seeds too shallow on sand risk lack of moisture.
     
    3
    When planting a mix of several species, find an appropriate seeding depth most acceptable for the majority of species with similar seed size in the mix. If this isn’t possible, planting equipment with a separate seed box is needed.
     
    4
    In uneven fields, consistent seeding depth is more challenging. Drill/planter set up is key. On no-till drills, planting depths are adjusted by cutting depth of the rolling coulter in front of the drill. Normally, the coulter should cut/slice the soil twice as deep as the planned planting depth. On most drills, the disk openers and press wheels work in tandem to affect down pressure and proper seed depth.
     
    5
    Each spring, a test run before tackling a larger area safeguards against errors. Some growers may even spray paint some seed to start, making it easier to locate and check depth. Adjustments may be necessary along the way to make up for changes in moisture or soil type.