Specs are compiled from manufacturer listings and verified buyer reviews and can change over time — please confirm the key details on the product page before buying.
You want a thick, green lawn. The standard advice tells you to reach for a bag of synthetic chemicals. But maybe you have kids, dogs, or a local stream you care about. That is where all-natural lawn fertilizers come in — they feed the soil instead of just force-feeding the grass, and they do it without the burn risk or the safety waiting period. The trick is picking the right one for your grass type, your season, and your patience level (natural formulas work a little slower, but the results last longer).
I’m Rikta — the founder and writer behind Lawn Gear Lab. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
The six products below cover every scenario from a spring renovation to a summer stress rescue, each backed by real buyers who actually used them. Read on for the clearest breakdown of the best all natural lawn fertilizer options available right now.
Quick Picks
- Espoma Organic Spring Lawn Booster 8-0-0 — Best Overall
- Sustane All Natural Lawn and Landscape Plant Food 8:2:4 — Top Performer
- Purely Organic Products Lawn Food 10-0-2 — Family Favorite
- Lawnbox Lawn Luxe 7-0-7 100% Organic Summer Grass Fertilizer — Summer Specialist
- Down To Earth Bio-Turf All Natural Fertilizer 8-3-5 — Deep Root Builder
- Alaska Fish Fertilizer OMRI Listed 5-1-1 — Budget Champion
How To Choose The Best All Natural Lawn Fertilizer
Switching to organic means thinking about what your lawn really needs, not just dumping a high-nitrogen blast. Here are the three decisions that matter most.
Read the N-P-K Ratio for Your Season
The three numbers on the bag — nitrogen (N), phosphorus (P), and potassium (K) — tell you exactly what the fertilizer delivers. High nitrogen (the first number) drives leafy green growth in spring. A balanced or higher potassium (the third number) helps roots handle summer heat and drought. Many organic blends keep phosphorus low (the second number reads zero) to meet local runoff regulations. Choose a ratio that matches your current season: 8-0-0 for a spring green boost, 7-0-7 for summer stress, and 8-2-4 for all-around feeding.
Check the Source: Slow-Release vs. Quick-Feed
Natural fertilizers come from different materials — fish emulsion works fast but fades in a few weeks, while feather meal or manure-based granules release nitrogen slowly over a month or more. Quick-feed liquids (like the Alaska Fish Fertilizer) are great for container plants or a fast pick-me-up, but you need to reapply every three weeks. Granular options with slow-release nitrogen (like the Espoma or Sustane) feed steadily for six weeks, which means fewer applications and steadier growth.
Match the Bag to Your Yard Size
Coverage varies wildly between products. A 30-pound bag of Espoma covers up to 5,000 square feet, while a 15-pound bag of Purely Organic covers 3,000 square feet. If you have a smaller lawn (under 2,500 square feet), a 14-pound or 15-pound bag is plenty and easier to store. For a quarter-acre lot, you will want the larger bags to avoid buying multiple boxes. Always check the square footage on the label rather than guessing by bag weight — the density of organic materials varies.
Quick Comparison
| Model | Best For | N-P-K Ratio | Coverage | Form | Amazon |
|---|---|---|---|---|---|
| Espoma Organic Spring Lawn Booster | Spring green-up on large lawns | 8-0-0 | 5,000 sq ft | Granules | Amazon |
| Sustane All Natural Lawn Food | Balanced all-season feeding | 8:2:4 | 20 lb | Granules | Amazon |
| Purely Organic Lawn Food | Pet-safe, no-smell granular | 10:0:2 | 3,000 sq ft | Granules | Amazon |
| Lawnbox Lawn Luxe 7-0-7 | Summer heat and drought stress | 7-0-7 | 2,500 sq ft | Granules | Amazon |
| Down To Earth Bio-Turf | Deep root development | 8-3-5 | 25 lb | Granules | Amazon |
| Alaska Fish Fertilizer | Quick liquid feed for plants | 5-1-1 | 1,000 sq ft | Liquid | Amazon |
In‑Depth Reviews
1. Espoma Organic Spring Lawn Booster 8-0-0
The heavy lifter that simply cannot burn your grass, even in a pile.
This is the one that solves the biggest fear for anyone switching to organic: the worry that you will turn your lawn brown. Espoma’s 8-0-0 formula feeds with slow-release nitrogen from natural ingredients (no sludges or toxic fillers) and adds extra calcium for cell strength. The 30-pound bag covers up to 5,000 square feet, making it the best value per square foot of any granular option here — it covers 60% more ground than the Purely Organic 3,000-square-foot bag for about the same cost.
Buyers report a memorable hands-on demo of its safety. One owner accidentally dumped a thick pile of Espoma on a lumpy spot and came outside to find a “thick tuft of deep deep green grass” where the overdose landed. The main trade-off is the application experience: the dried-manure base creates a powdery brown fog when broadcast, coating clothes, shoes, and skin. The smell is strong for a couple of days, though it fades. Still, if you want the most simple to use, large-area organic feed for spring, this is the bag to grab.
Unlike the Alaska Fish Fertilizer (which needs mixing and reapplying every three weeks), Espoma’s granules work with any drop or broadcast spreader and feed steadily for weeks. It is approved for organic production and works on cool-season grasses like fescue and bluegrass as well as warm-season types like St. Augustine and zoysia.
The one for big lawns: If you have a quarter-acre or more and want a single-bag solution that greens up spring grass without any burn risk, Espoma is your pick.
The one catch: The powdery dust during application is real — wear a mask and old clothes, and be ready to shower after.
Reach for this if: You have a large lawn (up to 5,000 sq ft), you want zero burn risk, and you are okay with a smelly, dusty application for the best organic value.
Look elsewhere if: You cannot tolerate strong odors during application or you need a no-dust, no-smell formula your neighbors will not complain about.
2. Sustane All Natural Lawn and Landscape Plant Food 8:2:4
The balanced feeder that delivers professional results without guessing.
Where the Espoma is a spring-specific nitrogen booster, Sustane’s 8:2:4 formula brings phosphorus and potassium into the mix for more complete plant health. The nitrogen is slow-release and organic, meaning it feeds steadily instead of causing a quick growth spurt that fades. The manufacturer cites independent research showing it produces more abundant growth than other organic and synthetic fertilizers.
Buyers advise a smart caution: apply in small quantities rather than dumping the full dose at once. One reviewer noted that the compostable kelp meal and organic matter can burn plants in the first week if over-applied — though the lawn bounced back healthier than ever after. The recommended schedule is one feeding every 25 days, which is straightforward enough to set a calendar reminder. Several reviewers mentioned their lawns bounced back from winter freeze damage and looked “wow” after switching to Sustane.
Compared to the Purely Organic 10-0-2, Sustane offers a 25% more balanced ratio that supports root and flower development (the 2 and 4 numbers) rather than just green leaves. It is a better choice if you want an all-season maintenance feed rather than a single-purpose spring or summer product.
The set-and-forget choice: Feed every 25 days with the granular formula and watch steady, balanced growth across your whole landscape.
The honest warning: It can burn if you over-apply the first time — follow the directions for top dressing and you will be fine.
Reach for this if: You want a single organic fertilizer that works on lawns, flower beds, and vegetable gardens with a simple monthly schedule.
Look elsewhere if: You need a super-high nitrogen formula (like 8-0-0) for a quick spring green-up on an already-healthy lawn.
3. Purely Organic Products Lawn Food 10-0-2
The no-smell, pet-safe granular that turns yellow grass green in four days.
If the strong odor of the Espoma or the fish smell of the Alaska fertilizer turns you off, this is the answer. Purely Organic uses a plant-based formula with distillers grains and soy — no manure, no smelly biosolids, and no fish. The 10-0-2 ratio delivers a high nitrogen punch (the 10) for rapid greening, while the zero phosphorus means it meets local regulations that restrict phosphate runoff. The 15-pound bag covers 3,000 square feet, and at 240 ounces, it holds 7% more volume than the Lawnbox 224-ounce bag for a similar yard footprint.
Owners mention impressive speed: one customer’s yellow grass turned green in 4 days. The same reviewer noted it is all-natural, contains no glyphosate (a common weed killer), and is safe for dogs, horses, and chickens — no re-entry waiting period, so kids and pets can walk on the lawn immediately. Another buyer simply said “my lawn looks great and my dogs can safely walk on it.”
There is no real catch with this product for most homeowners. The only thing to note is that the high-nitrogen, zero-phosphorus formula is designed for lawns that already have decent root systems — if your soil is truly depleted, you might need a more balanced feed like the Sustane 8:2:4 for the first season.
What owners love
- No smell at all during or after application
- Safe for pets and kids immediately — no waiting period
- Fast results: yellow to green in 4 days reported
- No phosphorus, so it meets local phosphate restrictions
What to consider
- High nitrogen (10) with zero phosphorus — may not fix deep soil deficiencies
- Granular, so you need a spreader for even coverage
Your pick if: You have pets, kids, or a sensitive nose and want a fast-greening organic granular with zero smell and immediate lawn access.
skip it if: Your lawn needs phosphorus or potassium to build strong roots — look at Sustane or Down To Earth instead.
4. Lawnbox Lawn Luxe 7-0-7 100% Organic Summer Grass Fertilizer
The summer rescue formula that helps grass stand up to heat, traffic, and drought.
Most fertilizers focus on spring green-up. Lawnbox Lawn Luxe targets the exact season when your lawn struggles most — summer. Its 7-0-7 ratio balances nitrogen and potassium (the third number) to encourage deep roots and better water retention, while humic acid in the mix promotes healthy soil biology. It delivers both quick-release and slow-release nitrogen, giving you an immediate green-up within days plus steady feeding for up to six weeks from a single application.
Customers note visible improvement in just 3 days, with greener and thicker blades after the first and second applications. One reviewer in a hot climate noted the product “works on soil, not harmful to water systems” — a real advantage over synthetics that can wash into storm drains. The 14-pound bag covers 2,500 square feet, which is ideal for average suburban lots. It contains no animal byproducts, manures, or biosolids, so there is no foul smell to deal with.
One limitation: it is not sold in California or Oregon, so check availability if you live on the West Coast. It also does not contain phosphorus (the 0 in the middle), so it is not a complete soil-builder for deficient ground. Pair it with a balanced spring feed like Sustane for year-round results.
The heatwave helper: If your lawn droops every August, this potassium-rich formula builds the root strength it needs to stay green through the hottest weeks.
The fine print: No CA/OR sales, and zero phosphorus means it is a seasonal tool, not an all-in-one feed.
Reach for this if: You want a dedicated summer organic fertilizer that handles heat stress, drought, and foot traffic without smell or animal-waste ingredients.
Look elsewhere if: You live in California or Oregon, or you need a phosphorus-containing formula for new lawns or depleted soil.
5. Down To Earth Bio-Turf All Natural Fertilizer 8-3-5
The OMRI-listed formula that cuts watering needs by building deep root systems.
Down To Earth brings a unique 8-3-5 ratio that includes phosphorus (the 3) and a notable amount of potassium (the 5) — a combination designed to encourage deep root development and reduce how often you need to water. It is OMRI listed for organic production, and the ingredients read like a farmer’s pantry: feather meal, fish meal, blood meal, meat meal, bone meal, and langbeinite (a natural mineral source of potassium and magnesium). The 25-pound bag is well-sized for smaller to mid-sized lawns. At 400 ounces of product, it offers more total volume than the Lawnbox 224-ounce bag, but at a higher entry price.
Reviewers point out excellent results when paired with aeration and overseeding — one said “our yard looks the best it has in years” after that combination. Another notes it works on bamboo container plants just as well as lawns. The non-burning formula is a strong alternative to harsh chemical fertilizers, though one buyer points out it is “pricey” upfront but potentially saves money on pre-emergent weed controls later.
Unlike the Purely Organic (which focuses exclusively on nitrogen for fast green), Bio-Turf invests in the whole plant — root strength, stress tolerance, and long-term soil health. If you are willing to spend a little more on professional-grade organic nutrition, this is the bag to open.
Your pick if: You are serious about organic lawn care, want to reduce watering, and value OMRI-listed ingredients from natural protein meals and minerals.
pass on it if: You are on a tight budget or only need a quick nitrogen boost — the Purely Organic or Espoma are cheaper for that job.
6. Alaska Fish Fertilizer OMRI Listed 5-1-1
The liquid fish feed that makes tomatoes blossom in 1-2 weeks.
If granular spreaders are not your thing or you want to spot-feed specific plants, the Alaska Fish Fertilizer is a time-tested liquid option. Its 5-1-1 ratio is rich in nitrogen (the first number) for vegetative growth — think leafy vegetables, herbs, perennials, and shrubs — and it is certified by OMRI for organic use. The 115-fluid-ounce jug covers 1,000 square feet, making it a perfect match for smaller lawns, garden beds, or container plants. It covers a 3.0x smaller area than the Purely Organic granular.
Shoppers say powerful results: one reviewer says it “produced stronger stems, vibrant leaves, and faster growth” with tomatoes blossoming within 1-2 weeks. Another revived sad houseplants in January and saw success on perennials and roses. The fishy smell is the main drawback — several buyers mention it is pungent. However, most agree the odor dissipates within a day when used outdoors. The formula is deodorized to reduce smell compared to raw fish emulsion.
The liquid form gives you control you cannot get from granules: you mix it with water and apply with a hose-end sprayer or watering can, targeting specific plants without broadcasting over the whole lawn. The trade-off is frequency — you need to apply every three weeks during the growing season, while a granular like Espoma feeds for weeks from one application.
Why gardeners love it
- OMRI listed for certified organic gardening
- Won’t burn plants when used as directed
- Boosts soil microbes and organic matter
- Great for vegetables, herbs, shrubs, and containers
What to know
- Pungent fish smell during and right after application
- Needs reapplication every 3 weeks — less convenient than granules
- Covers only 1,000 sq ft per bottle — better for gardens than large lawns
Reach for this if: You want a fast-acting organic liquid for vegetable gardens, containers, or spot-treating specific plants, and you do not mind a temporary fish smell.
Look elsewhere if: You need to cover a large lawn (over 1,000 sq ft) or you want a low-maintenance granular that lasts weeks between applications.
Understanding the Specs
N-P-K Ratio Explained
Those three numbers on the bag (like 8-0-0 or 7-0-7) are the fertilizer’s promise. The first number is nitrogen (N), which drives leaf and blade growth and gives your lawn that deep green color. The second is phosphorus (P), which supports root and flower development — many organic lawn fertilizers leave it at zero to comply with local phosphate bans. The third is potassium (K), which strengthens cell walls and helps grass survive heat, drought, and foot traffic. For a spring lawn, go high on the first number. For summer, look for a higher third number. For an all-purpose feed, aim for a balanced ratio like 8-2-4.
OMRI Listing vs. “Natural” Label
OMRI (the Organic Materials Review Institute) is an independent nonprofit that verifies a product meets USDA organic standards. A fertilizer stamped “OMRI Listed” has been reviewed and approved for use in certified organic production — that is the gold standard. A bag that just says “natural” or “all-natural” has no third-party verification behind it. If organic integrity matters to you, look for the OMRI logo. Products like the Alaska Fish Fertilizer and Down To Earth Bio-Turf carry it; the Purely Organic and Lawnbox do not, though they are still made from plant-based or mineral ingredients.
FAQ
Can I use all natural lawn fertilizer in the summer?
How long does it take for organic fertilizer to turn my lawn green?
Will all natural fertilizer burn my lawn?
Is it safe for dogs to walk on the lawn after applying organic fertilizer?
What is the difference between 8-0-0 and 10-0-2 fertilizer?
Can I use fish fertilizer on my lawn or is it only for gardens?
Why do some organic lawn fertilizers have zero phosphorus?
How do I apply granular organic fertilizer evenly without streaks?
Is all natural lawn fertilizer more expensive than synthetic?
What is the best all natural lawn fertilizer for new grass seed?
Final Thoughts: The Verdict
If you want one dependable pick, the best all natural lawn fertilizer winner is the Espoma Organic Spring Lawn Booster because it delivers class-leading coverage (5,000 sq ft from one 30-pound bag), zero burn risk even with heavy application, and a slow-release nitrogen source that keeps grass green for weeks. If you want a balanced, no-smell granular that is safe for pets and kids immediately, grab the Purely Organic Lawn Food 10-0-2. And for keeping your lawn healthy through the hottest months, the standout is the Lawnbox Lawn Luxe 7-0-7 with its potassium-rich summer formula and built-in humic acid.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
As an Amazon Associate, Lawn Gear Lab earns from qualifying purchases. This does not affect which products we feature.