Hydroseeding cost

Hydroseeding costs $0.10 to $0.25 a square foot, typically around $0.15, for seed, mulch, fertilizer and water sprayed onto prepared soil. A 5,000 square foot lawn is therefore $500 to $1,250, and about $750 at the typical price. Sodding the same area is $5,000 to $12,500.

The spray is the cheap part. What decides whether it comes up is the soil under it, and preparation at $0.30 to $1.50 a square foot often costs more than the hydroseeding itself.

What it costs

Small lawns hit the minimum charge. Large, open areas drift toward the bottom of the per-foot range, because the truck, the setup and the drive are spread over more ground.

What is in the tank

The truck mixes a slurry of five things and sprays it from a hose that reaches well over 100 feet from the tank:

• Seed, chosen for sun, shade and climate
• Mulch, usually wood or paper fiber, which holds moisture against the seed and shields it from birds and wind
• Starter fertilizer
• Tackifier, a plant-based glue that binds the mulch to the soil so it does not wash off
• Green dye, so the operator can see where the coverage is even

It dries within a day into a light crust that keeps the seed moist and in place. That is the whole advantage over seed spread by hand: the seed does not blow away, wash into the gutter or feed the local birds.

What hydroseeding does not do is prepare the soil. Sprayed onto compacted clay or a builder's leftover subsoil, it germinates and then thins out over the first summer.

Hydroseed, seed or sod

Seed spread dry by a contractor with straw cover costs roughly the same per square foot, and by hand yourself costs far less. It is fine on flat ground and small areas, and it loses more seed to birds, wind and heavy rain.

Hydroseeding gives even coverage over large areas, holds on slopes, and reaches awkward corners from the hose. It still takes six to ten weeks to look like a lawn and a full season to take real use.

Sod is a finished lawn in two to three weeks at around ten times the price. The trade-offs are covered in detail in sod installation costs.

Hydroseeding makes most sense for:

• Areas over about 5,000 square feet, where it is far cheaper than sod
• Slopes and banks where dry seed would wash off
• New construction, where the whole lot is bare at once
• Awkward shapes a hose can reach and a sod pallet cannot

It makes least sense for a small patch under the minimum charge, deep shade under trees, a lawn you have no way to water, or a yard the children and dog need next month.

Slopes and large areas

Gentle slopes, up to about one foot of rise for every three across, hold hydroseed well with a standard tackifier.

Steeper banks need more tackifier, a bonded fiber mix, or an erosion-control blanket over the seed. That adds $0.05 to $0.15 a square foot and it is money well spent: a heavy storm in the first two weeks will otherwise carry the seed and mulch to the bottom of the slope.

Large areas are where hydroseeding earns its keep. One large truck covers a quarter acre or more per tank, so an acre is a morning's work, and at $4,400 to $6,500 an acre it is the cheapest way to establish a lawn or a meadow mix that has a reasonable chance of surviving.

Timing matters more than price. For cool-season grasses, early fall gives the seed warm soil and cool air with weeds slowing down. For warm-season grasses such as Bermuda, late spring once the soil is above about 65°F. Spraying in midsummer is possible and needs water every day without fail.

Where water runs across the area in heavy rain, fix the drainage first. See yard grading before paying for seed that will wash away.

Germination and watering

First two weeks. Water lightly two or three times a day to keep the top inch of soil moist. Not so much that water pools or runs, which washes the mulch. Stay off it entirely.

Germination starts at five to ten days for ryegrass, seven to fourteen for tall fescue, and two to four weeks for bluegrass. A mix comes up in stages, so a patchy look at day ten is normal.

Weeks three to six. Once most of the seed is up, water once a day, then every other day, deeper each time to drive the roots down.

First mow when the grass reaches three to four inches, usually around four weeks, with a sharp blade and taking off no more than a third.

Light use from about eight weeks, and full use after one growing season.

Budget $75 to $250 in extra water for the first month on a typical lawn. Hand-watering 5,000 square feet three times a day is miserable, and an existing or temporary sprinkler system on a timer is what most successful hydroseeded lawns have in common.

Frequently asked questions

Is the green color on fresh hydroseed the grass?

No. It is dye in the mulch, and it fades within a week or two. The grass itself does not show until germination, five days to four weeks depending on the seed. A green lawn on day two is the mulch, not a sign that it worked.

What happens if heavy rain hits hydroseed in the first week?

Light rain helps. A downpour on a slope or on bare, unmulched patches can wash seed and mulch into channels and leave streaks with nothing growing. Most contractors will quote a touch-up visit at $100 to $300. Ask before booking whether washout within the first two weeks is re-sprayed at no cost.

Is there a minimum area where hydroseeding makes sense?

Roughly 2,000 to 3,000 square feet. Below that, the minimum job charge of $400 to $1,000 makes each square foot more expensive than a contractor spreading seed and straw, and closer to the price of sod on a very small area.

Can hydroseed be sprayed over an existing patchy lawn?

It can, and it works poorly on its own. The slurry sits on top of the old grass and thatch rather than reaching the soil. On a lawn that is thin rather than bare, core aeration with overseeding is cheaper and more reliable. Where most of the lawn is bare or weeds, kill and strip it, prepare the soil, then hydroseed.

When can weed control go on a hydroseeded lawn?

Not until the new grass has been mowed three or four times, usually six to eight weeks after spraying. Pre-emergent crabgrass control stops grass seed from germinating, so it cannot go down before or soon after hydroseeding at all. Pull the early weeds by hand, and most annual weeds disappear once the lawn is mowed regularly.