Lawn fertilization cost

Lawn fertilization costs $50 to $120 per application for a 5,000 square foot lawn, typically around $80, with broadleaf weed control usually included. Most programs are five or six applications a year, which is $250 to $720, and about $450 at the typical price. The same five rounds done yourself with bagged fertilizer and a spreader cost $125 to $300 in product.

The price of one application tells you very little. What decides the annual bill is how many rounds the program sells, what is in each, and whether the lawn needed that many in the first place. Plenty of lawns are fed more than they can use, and a soil test is the cheapest way to find out.

What it costs

Lawns much larger than a quarter acre are usually priced per thousand square feet, and the per-foot rate falls as the area grows.

Test the soil before buying a program

A soil test from a state extension service costs $15 to $60 and reports pH, phosphorus, potassium and organic matter. It is the most useful $30 in lawn care.

pH comes first. Most turf grasses want soil between 6.0 and 7.0. Below about 5.5, much of the fertilizer you pay for is simply not available to the grass. Lime corrects acid soil at $60 to $150 an application, and it takes months to move the number, so it is a job for fall.

Phosphorus is often unnecessary. Many established lawns already have plenty, and a number of states restrict phosphorus in lawn fertilizer unless a test shows a deficiency, because it runs off into lakes and feeds algae.

Nitrogen is the one the grass actually uses up, and it is what the program is mostly selling.

Ask any company you are considering whether they test, and whether the program changes because of the result. A program that sends the same six rounds to every house on the street is selling a calendar, not lawn care.

What five or six rounds are for

A typical program for a cool-season lawn:

1. Early spring: pre-emergent crabgrass control with a light feed
2. Late spring: fertilizer with broadleaf weed control for dandelions and clover
3. Early summer: slow-release fertilizer, often with grub prevention sold as an add-on
4. Late summer: a light feed or a weed control round
5. Early fall: fertilizer, the most valuable round of the year for recovery and root growth
6. Late fall: a winterizer to store energy before dormancy

The early fall and late spring rounds do most of the work. A well-timed four-round program covering early spring, late spring, early fall and late fall gets most lawns most of the result, at around $320 at the typical price.

Warm-season grasses such as Bermuda, zoysia and St Augustine are the other way round: they are fed from late spring through summer, when they grow, and not in fall.

Fertilizer works far better on a lawn that is not compacted, which is why most programs sell core aeration alongside.

Granular or liquid

Granular fertilizer is spread dry. Good granular products are largely slow-release and feed evenly for six to eight weeks. Granular weed control is slower, because it needs to stick to wet leaves to work.

Liquid is sprayed from a tank on the truck. It greens a lawn within days and the weed control coats the leaves well, and it feeds for a shorter time unless the mix includes slow-release nitrogen. National treatment companies favor liquid because it is fast to apply.

The price is usually the same, and the form matters less than the product. The useful question is what share of the nitrogen is slow-release. Somewhere around 30 to 50% is good. A cheap, fast-release product greens the lawn quickly, pushes soft top growth that needs more mowing, and washes out sooner.

Organic programs

Organic programs cost 20 to 50% more. Organic fertilizers contain far less nitrogen by weight than synthetic ones, so more product is spread per round, and the materials cost more to begin with.

What you get is better soil structure and more biological activity over several years, and less runoff near a lake, stream or well.

What you give up is weed control. Organic pre-emergents such as corn gluten meal are modest at best, and there is no organic broadleaf weed killer that matches the conventional ones. Expect more weeds for the first two or three seasons, and plan to pull some by hand or accept a few.

Starting a new lawn, seeded or sodded, in good soil with an organic program from day one avoids most of that transition.

Frequently asked questions

How long should children and dogs stay off the grass after a treatment?

For a liquid treatment, until it has dried, usually one to two hours on a warm day. For granular fertilizer, until it has been watered in. Weed control products carry their own label instructions, and the applicator should leave a flag and a note saying what was applied.

Why do I still have weeds after three lawn treatments?

Usually one of three reasons. The weeds are grassy types such as crabgrass or nutsedge that broadleaf weed control does not touch. The lawn is thin, so weeds keep germinating into the gaps faster than they are killed. Or it rained within a few hours of a liquid spray. Most programs re-treat for free between rounds, so call them.

Does fertilizing more often make a thin lawn thicken faster?

No. Extra nitrogen pushes leaf growth rather than new plants, and too much in summer invites disease. A thin lawn thickens from overseeding into soil that has been aerated, then fed in fall. Paying for an extra round is not a substitute for seed.

What happens if it rains right after the lawn is treated?

Light rain after granular fertilizer is ideal, since it waters the product in. Heavy rain within a few hours of a liquid weed control spray can wash it off before it works, and a reputable company re-applies at no charge. Heavy rain on fertilizer left on the driveway washes it into the storm drain, which is why a careful applicator blows the hard surfaces clean.

Should the program change on a lawn with an irrigation system?

Yes, a little. A lawn watered all summer grows steadily and can use a summer feed that a dry, dormant lawn cannot. The reverse also applies: an irrigated lawn watered too often leaches nitrogen past the roots, so the controller is worth setting properly before paying for more fertilizer.