Lawn Care
Best fertilizer for new grass
The middle number is the one that matters here, and the bag most people reach for has a zero in it.
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We have not tested these units. Every spec on this page comes from the manufacturer's own documentation and is linked to it. Every computed figure is arithmetic you can redo. Prices are checked daily — last verified January 1, 1970. Here is exactly how we pick.
Quick picks
Ranked on the published specs and the arithmetic below. Tap any row to jump to the full write-up. We have not tested these units -- here is exactly how we pick.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | No photo Jonathan Green Veri-Green Starter Fertilizer for Seeding & Sodding (12-18-8) 18% phosphate is the whole point: new seed is building roots, and a starter analysis puts phosphorus where a lawn food does not. | Best for new seed | 8.9 | |
| 2 | No photo Milorganite Slow-Release Nitrogen Fertilizer (6-4-0) A 6-4-0 analysis with 2.5% iron that puts 0.77 lb of nitrogen per 1,000 sq ft down at the bag rate -- under the Extension ceiling by arithmetic, not by luck. | Best low-burn option | 8.4 | |
| 3 | No photo Jonathan Green Veri-Green Nitrogen Rich Lawn Fertilizer (29-0-3) 29-0-3 with 40% slow release and 4% iron, and the only bag here whose published coverage lands almost exactly on 1 lb of nitrogen. | Best documented rate | 8.8 |
#ad Buy links are affiliate links. Prices come from a live daily check; where we have no verified price we say "check price" rather than print a stale one.
Fertilizer for a new lawn is one of the few places where the middle number on the bag decides the purchase. Seedlings are building roots, not blades — and the lawn food most people already own has a zero where the root nutrient should be.
The short answer
Why the middle number decides it
The three numbers on a fertilizer bag are nitrogen, phosphate and potash. Nitrogen drives leaf growth; phosphate drives root development. A new seeding needs the second and is harmed by too much of the first.
That is the whole argument on one maker's own two bags, which is the cleanest comparison available because the coverage tables are identical.
Three bags, one job
| Spec | JG Starter 12-18-8 | Milorganite 6-4-0 | JG Veri-Green 29-0-3 |
|---|---|---|---|
| Analysis | 12-18-8 | 6-4-0 | 29-0-3 |
| N per 1,000 sq ft | 0.36 lb | 0.77 lb | 0.87 lb |
| Phosphate per 1,000 sq ft | 0.54 lb | Present (4%) | None |
| Slow release | 25% | Not published as a share | 40% |
| Feeding duration | 2 months | 8-10 weeks | 3 months |
| When to apply | Same day as seeding or sodding | Any feeding | Established lawns |
| Right for new seed? | Yes | Workable | No |
Transcribed from Green-Up Fertilizer for Seeding & Sodding, Milorganite and Veri-Green Nitrogen Rich. Per-1,000 sq ft figures are our arithmetic from each maker's coverage table.
1. Jonathan Green Veri-Green Starter (12-18-8) — the right analysis
Eighteen percent phosphate, twelve percent nitrogen, 25% of the nitrogen slow-release, and instructions that say to put it down the same day you seed. Three bag sizes cover 1,500 to 15,000 sq ft.
The 0.36 lb of nitrogen per 1,000 sq ft is the number that keeps seedlings alive. Grass at three days old has no root system to buffer a salt load, and a heavy nitrogen application is exactly that.
Against it: two months of feeding rather than three, and muriate of potash as the potassium source, which brings chloride with it. And the rate per 1,000 sq ft has to be derived from the coverage table rather than read off the bag.
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2. Milorganite (6-4-0) — the workable organic alternative
Six percent nitrogen and four percent phosphate. The analysis is much gentler than a lawn food, it carries phosphate where the lawn foods do not, and it feeds for a published 8-10 weeks.
At 0.77 lb of nitrogen per 1,000 sq ft it is more nitrogen than the starter bag delivers, which is why it sits second rather than first here. On an established lawn that figure is ideal; on three-day-old seedlings it is more than they need.
Where it wins is on soil that has never had organic matter added. That is a real benefit on a new-build lot scraped back to subsoil.
#ad Check the Milorganite Slow-Release Nitrogen Fertilizer (6-4-0) price on Amazon — how we're funded.
3. Jonathan Green Veri-Green (29-0-3) — the bag not to use yet
This is an excellent fertilizer and the wrong one for this job. Twenty-nine percent nitrogen, 40% of it slow-release, 4% iron, three months of feeding — and zero phosphate.
Put it down on a new seeding and you deliver 0.87 lb of nitrogen per 1,000 sq ft to grass that cannot use it, with nothing at all for the roots. Keep it for the lawn a season from now, when it becomes the best bag on this list. Our best lawn fertilizers page is where it belongs.
#ad Check the Jonathan Green Veri-Green Nitrogen Rich Lawn Fertilizer (29-0-3) price on Amazon — how we're funded.
Test before you assume you need phosphate
Plenty of soils already hold enough phosphorus, and adding more does nothing for the lawn and something unwelcome for the watershed. A mail-in kit answers this in about a week — see best soil test kits and fertilizer numbers explained.
What we cannot tell you
We have not run a seeding trial. No maker publishes a seedling burn threshold, and the Milorganite publishes no slow-release share at all, so its release curve cannot be compared with the two coated bags. The right rate for your lawn depends on a soil test we have not seen.
The picks in full
Specs are the manufacturer's own and linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
Jonathan Green Veri-Green Starter Fertilizer for Seeding & Sodding (12-18-8)
Jonathan Green · Fertilizer (no power) · Our score 8.9/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
18% phosphate is the whole point: new seed is building roots, and a starter analysis puts phosphorus where a lawn food does not.
Published specs
| Guaranteed analysis | 12-18-8 |
|---|---|
| Coverage | 5 lb covers 1,500 sq ft; 15 lb covers 5,000 sq ft; 45 lb covers 15,000 sq ft |
| When to apply | The same day you seed or lay sod |
| Seeding windows | Mid-August to mid-October, or mid-March to mid-May |
| Slow release | 25% |
| Feeding duration | 2 months |
| Derived from | Urea, polymer-coated urea, muriate of potash, diammonium phosphate |
Source: Green-Up Fertilizer for Seeding & Sodding, jonathangreen.com
15 lb over 5,000 sq ft is 15 / 5 = 3 lb of product per 1,000 sq ft. At 12% nitrogen that is 3 x 0.12 = 0.36 lb N -- deliberately low, because seedlings burn. At 18% phosphate it is 3 x 0.18 = 0.54 lb of P2O5, which is the figure a 0-phosphate lawn food cannot deliver at any rate. The 5 lb bag works out identically: 5 / 1.5 = 3.33 lb per 1,000 sq ft, close enough that the coverage table is internally consistent.
What the numbers favor
- 18% phosphate, the nutrient new roots need and most lawn foods now omit
- 0.36 lb N per 1,000 sq ft is gentle enough for seedlings
- 25% slow release published as a percentage
- Three bag sizes, from a 1,500 sq ft patch to 15,000 sq ft
- Nitrogen sources named individually on the label
What they don't
- Feeds two months, against three for the same maker's established-lawn bag
- Phosphorus is restricted on established lawns in several states -- this is a new-lawn product only
- Muriate of potash means chloride, which some soils do not need more of
- The rate per 1,000 sq ft has to be derived from the coverage table, not read off the bag
your lawn is already established. At that point phosphate is the nutrient you are least likely to be short of, and several states restrict it.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Milorganite Slow-Release Nitrogen Fertilizer (6-4-0)
Milorganite · Fertilizer (no power) · Our score 8.4/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
A 6-4-0 analysis with 2.5% iron that puts 0.77 lb of nitrogen per 1,000 sq ft down at the bag rate -- under the Extension ceiling by arithmetic, not by luck.
Published specs
| Guaranteed analysis | 6-4-0 (6.0% N, 4.0% P, 0.0% K) |
|---|---|
| Iron | 2.5% |
| Bag sizes | 32 lb and 5 lb |
| Coverage | 32 lb covers 2,500 sq ft |
| Feeding duration | 8-10 weeks |
| Bag dimensions | 22 x 13.25 x 4.75 in |
| Slow-release share | Not published on the specification page |
| Application rate per 1,000 sq ft | Not published directly |
Source: Product Specifications, milorganite.com
32 lb over 2,500 sq ft is 32 / 2.5 = 12.8 lb of product per 1,000 sq ft. At a 6% nitrogen analysis that is 12.8 x 0.06 = 0.77 lb of nitrogen per 1,000 sq ft. University of Minnesota Extension publishes a ceiling of 1 lb of nitrogen per 1,000 sq ft in any single application, so the bag rate lands under it with room to spare -- which is the whole argument for a low-analysis slow-release product.
What the numbers favor
- 0.77 lb N per 1,000 sq ft at the bag rate, inside the Extension ceiling without measuring anything
- 2.5% iron, which is what produces color without pushing growth
- Feeds 8-10 weeks on a published figure
- Low analysis means a spreader misfire is far less costly than with a 32-0-4
What they don't
- 12.8 lb of product per 1,000 sq ft is four times the bulk of a high-analysis fertilizer -- more bags, more carrying
- Contains 4% phosphate, which several states restrict on established lawns unless a soil test calls for it
- The specification page publishes no slow-release percentage and no rate per 1,000 sq ft
your soil test shows adequate phosphorus or your state restricts phosphorus on established lawns. Read the label against your local rule before buying.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Jonathan Green Veri-Green Nitrogen Rich Lawn Fertilizer (29-0-3)
Jonathan Green · Fertilizer (no power) · Our score 8.8/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
29-0-3 with 40% slow release and 4% iron, and the only bag here whose published coverage lands almost exactly on 1 lb of nitrogen.
Published specs
| Guaranteed analysis | 29-0-3 |
|---|---|
| Slow release | 40%, from polymer-coated urea |
| Iron | 4% |
| Feeding duration | 3 months |
| Coverage | 15 lb covers 5,000 sq ft; 45 lb covers 15,000 sq ft |
| Application window | Mid-August to mid-October, or mid-March to mid-May |
| Phosphate | 0% |
Source: Veri-Green Nitrogen Rich Lawn Fertilizer, jonathangreen.com
15 lb over 5,000 sq ft is 15 / 5 = 3 lb of product per 1,000 sq ft. At 29% nitrogen that is 3 x 0.29 = 0.87 lb of nitrogen per 1,000 sq ft -- just under the 1 lb per application ceiling UMN Extension publishes, and 13% more nitrogen per pass than Milorganite's 0.77 lb. Both bags are inside the rule; this one gets there carrying a quarter of the product weight.
What the numbers favor
- 0.87 lb N per 1,000 sq ft at the bag rate -- close to the Extension ceiling without exceeding it
- 40% slow release published as a percentage, which almost no consumer bag states
- 4% iron for color
- Zero phosphate, so it sidesteps state phosphorus restrictions on established lawns
- 3 lb per 1,000 sq ft means a 15 lb bag covers a typical front lawn
What they don't
- A 29% analysis is unforgiving of a miscalibrated spreader; overlap stripes will show
- The product page does not state the rate per 1,000 sq ft directly -- it has to be derived from the coverage table
- Only two bag sizes
you have never calibrated your spreader. At this analysis, a double pass is a burn, not a blemish.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Where to buy the tools on this page
Every link below is an Amazon affiliate link. We show no price we have not verified today, so where there is no live figure the link says "check price" and takes you to the listing to read it there.
Best for new seed
Jonathan Green Veri-Green Starter Fertilizer for Seeding & Sodding (12-18-8)
Jonathan Green · Fertilizer (no power)
Best low-burn option
Milorganite Slow-Release Nitrogen Fertilizer (6-4-0)
Milorganite · Fertilizer (no power)
Best documented rate
Jonathan Green Veri-Green Nitrogen Rich Lawn Fertilizer (29-0-3)
Jonathan Green · Fertilizer (no power)
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Common questions
What is the best fertilizer for new grass?
Do you need starter fertilizer for new grass?
What NPK is best for new grass seed?
When do you apply starter fertilizer?
Can you use regular lawn fertilizer on new grass?
Sources
Read next
- Lawn Care
Cutting the grass is a third of the job. This is the other two thirds.
- Best lawn fertilizer
Analysis and coverage converted to pounds of nitrogen per 1,000 sq ft, against the Extension limit.
- What the three numbers on a fertilizer bag mean
N-P-K decoded, UMN's published nitrogen rates, and the maths that turns a bag into pounds.
- How to overseed a lawn
Published extension seeding rates, the late-summer window, and the passes-per-lawn arithmetic.
- Best grass seed
Coverage claims converted to pounds per 1,000 sq ft, checked against Extension seeding rates.
- Best soil test kit
Two mail-in lab kits on nutrients reported, nitrogen detail, turnaround and recommendations.