Seeding Methods

Table of Contents

There are three seeding methods: drill seeding, broadcasting and hydroseeding. Each has advantages and disadvantages.

Drill seeding

Seeding with a native grass drill is the preferred method on level rights-of-way. Drilling is a one-step process and is quicker and cheaper than hydroseeding. Drills do a better job establishing native grasses and produce faster results overall.

Drills do not work well on slopes. At 3:1 or steeper, the drill will try to slide sideways causing the disk openers to dig in and bury the seed. Projects with silt fences present another challenge; maneuvering a tractor and drill around these fences is difficult.

Drill seeding tips

  • Calibrate the drill in the shop and set the rate a little lighter than what you actually want.
  • Bouncing over the ground, a drill set at 6.5 lb. to the acre might actually seed 8 lbs. to the acre.
  • When planting very clean seed with an older drill, use a filler to slow it down. Bulk-harvested seed or fluffy little bluestem works well.
  • For good seed distribution, use the small seed box for fine seed and the fluffy seed box for grasses, large forb seed and seed that hasn’t been well-cleaned. Alternatively, sprinkle a portion of the forb seed on top of the other seed in the drill’s middle hopper, then add more forbs every other round or two.
  • Do not plant native seed deeper than ¼ in. Most native seed is small and lacks the energy to emerge if planted too deep.
  • The trash plow attachment on a native grass drill should just scratch the surface. If it’s making furrows, it’s planting too deep.
  • For uniform coverage, drill seed at a light rate and go over the area twice.
  • Multiple passes packs the seed well and creates more rills that hold seed and interrupt water flow.
  • To prevent seed from being buried too deep, disconnect the lower end of the drill’s seed tubes. Some of the seed will land on the soil surface and not be buried in the furrow. Some people prefer to unhook only every other tube. Others unhook only the tubes coming from the small seed box.

Hydroseeding

Hydroseeding is ideal for bridge approaches, cleanouts, culverts and wet or steep slopes. In most cases, the entire project can be hydroseeded from the shoulder. Other hydroseeding advantages — hydromulch reduces soil erosion; the risk of seeding too deep is eliminated; colored mulch on the soil makes a positive impression on the public.

Filling the hydroseeder takes time, so drilling or broadcasting are usually quicker for larger projects. Other hydroseeding disadvantages — mulch is expensive and can double the cost of a seeding, the seeding rate is harder to control, and hydroseeding is strictly a bare-ground application.

Hydroseeding tips

  • It’s best to seed after a rain, not just before. Seed and mulch stick better on moist soils. Some moisture is captured under the mulch. Mulch needs time to set up before it rains.
  • Increase overall seeding rate by 25% to compensate for seed damaged going through hydroseeder mechanics and for seed that gets hung up in the mulch.
  • The “shadow areas” behind larger dirt clods sometimes get no seed. For better coverage, try to seed in two passes, one from each direction. Seed lightly — so the seeding rate is not doubled — at 7 to 8 mph, with flow rate reduced.
  • An 800-gallon hydroseeder is the minimum recommended size. A 1,500-gallon hydroseeder can cover 1/3 acre per load. With a machine of this size, seven 50-lb. bales, or 350 lb. of mulch per load, yields about 1,000 lb./acre.
  • Seed the area farthest from the road first.
  • On steep slopes, try to embed the seed by using a more concentrated stream and holding the gun at a sharper angle.
  • For the sake of efficiency, most county roadside managers apply seed and mulch in one pass. The “two-pass method” — seed applied first, hydromulch to follow — results in better establishment since more seed is in direct contact with the soil.

Hydromulching rates

  • 1,000 lb./acre — a token amount to help carry the seed and show what area has been seeded
  • 2,000 lb./acre — appropriate for most 3:1 slopes
  • 3,000 lb./acre — very heavy rate for long, steep slopes

Broadcast seeding

Broadcast seeding is a viable option now that commercially available native seed is cleaner and less fluffy than it once was. When applied with broadcast seeding equipment, this debearded seed flows better and slings farther and truer than in the past.

Broadcast seeding tips

  • Broadcasting finer-seeded species prevents them from getting buried under too much soil.
  • For very clean seed, the Vicon broadcaster can be adjusted down to the “nth” degree.
  • For fluffy seed just open the gate a lot wider.
  • A broadcast seeder on a 3-point is more compact than a drill and easier to get in and out of ditches.
  • Broadcasters can be backed up to silt fences to sling seed on both sides.

Hand seeding

Scattering seed by hand followed by light raking is very effective for smaller sites and prevents fine seed from being planted too deeply.

  • To improve distribution, mix the seed with some kind of carrier. Sand is best. Kitty litter or oats are also used.
  • Mix the seed and carrier in a bucket and scatter it over the site by hand.
  • Many wet prairie species have fine seed and should be seeded this way.

Packing the seed

Packing seed tightly to the soil ensures a more consistent flow of moisture from the soil to the seed. The result is better germination and better seedling survival.

  • Packing is most important after broadcast seeding, but is always beneficial.
  • A 4-ft. cultipacker section on a 3-point is very effective and will go places the tractor and drill can’t.

Roadside Manager Insights

We lightly disk the seedbed before hydroseeding, if possible; cultipack after we seed; then apply mulch (two-pass method).

-Joe Kooiker, Story County, 2024

The hydroseeding is a great method of seeding, but not always necessarily the tool for the job.

-Joe Kooiker, Story County, 2024

When filling a hydroseeder from a creek, know your source. Don’t fill from an area with invasives (e.g., purple loosestrife).

-Jim Uthe, James Devig, Dallas County, 2024

Filling near the site with a trash pump has drastically improved the efficiency of the process. We mounted the pump on the seeder, so we simply drop a fill line into the water and turn on the pump.

-Josh Brandt, Cerro Gordo County, 2010

When hydroseeding, be sure to mix seed thoroughly in the water, both initially and periodically during application. Our Finn hydroseeder can reverse the mechanical agitation, which is helpful.

-Jim Uthe, James Devig, Dallas County, 2024

We have better germination with lighter hydromulch rates (400–500 lbs./acre).

-Dave Sedivec, Chickasaw County, 2010

There’s been some concern about high mulch rates affecting seed germination. I don’t think that’s an issue with large grass seeds, and even small seeds aren’t affected when dormant seeding with a high mulch rate since the mulch softens and breaks down over the winter. The seed can’t germinate if it’s washed away, so use enough mulch to get the job done right. 

-Jim Uthe, James Devig, Dallas County, 2024

When mixing seed, we mix 10 acres worth of the fluffy grass (sideoats, big blue, Indian, little blue and Canada wild rye) and compass plant and put it in large, plastic garbage cans. Then we mix 10 acres worth of the remaining forbs in a large Rubbermaid tote and put the two slick grass seeds (rough dropseed and switch) in a 3rd tote. Our fluffy grass rate is around 10–12 bulk lbs/acre, our forbs are usually around 3–4 and slick seed is around 2 lb./ac.

-Jim Uthe, James Devig, Dallas County, 2024

When hydroseeding, we bump these rates an extra 30 to 50% at times depending upon site conditions and current climatic factors. We pretty much always seed with mulch and we typically use 1,500 lbs. of wood fiber mulch per acre. Our 3,300-gallon unit seeds about 0.9 acres pretty well with 1,350 lbs. of mulch in it (3,600 gal. of material per acre). Some people I know put 1,500 lbs. in a 3300 gallon seeder and seed a full acre, but we always seem to run a little short doing it that way. 

-Jim Uthe, James Devig, Dallas County, 2024

Don’t trust your drill to meter your seed. Know your acreage and equally distribute the seed.

-Wes Gibbs, Jones County, 2024

When hydroseeding, you initially have to know how much area you are covering with a full load. With our Finn T-90, I cover a third of an acre per load. That may be more than is recommended for that size machine, but it means fewer loads per job and quicker to finish. With our 22-foot wide ROWs (average), we travel 660 feet to make that 1/3 of an acre. With practice you can become pretty accurate — arriving at 660 feet with an empty hydroseeder. If we use UNI’s recommended rates, then big bluestem at 1.5 lbs per acre, for example, uses 0.5 lbs per load. We weigh out the amount of each species needed for a 1/3 of an acre and put it in one bag ahead of time. Then we can just dump the bag in each load. This holds true for the nurse and temporary crops as well. 

-Linn Reece, Hardin County, 2011