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.
If your lawn looks more yellow than green, or your vegetables are stunted and pale, the quickest fix is a high-nitrogen fertilizer. But with numbers like 46-0-0 and 32-0-0 on the label, it is easy to grab the wrong bag and end up with scorched grass or wasted money. This guide breaks down five top-rated options — from fast-acting urea to slow-release blends — so you know exactly which one matches your garden or lawn.
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.
Whether you are nursing a nitrogen-deficient vegetable patch or chasing the thickest lawn on the block, finding the right high nitrogen fertilizer depends on matching the nitrogen percentage and release speed to your specific plants and watering habits.
Quick Picks
- The Andersons Professional Pure Nitrogen 32-0-0 — Best Overall
- Greenway Biotech, Inc. Urea Fertilizer Plant — Pro Grade
- Petramax Liquid Nitrogen Fertilizer 28-0-0 NPK — Value Pick
- The Dirty Gardener Nitrogen Fertilizer Urea — Budget Champion
- The Grow Co 5 lb. Urea Fertilizer 46-0-0 — Garden Favorite
How To Choose The Best High Nitrogen Fertilizer
High nitrogen fertilizers push green growth fast, but the wrong type on the wrong plant can do real damage. Here are the three things to look for before you buy.
Nitrogen Percentage and the N-P-K Label
Every fertilizer label shows three numbers — the N-P-K ratio (Nitrogen-Phosphorus-Potassium). The first number is nitrogen. A high nitrogen fertilizer has that first number significantly higher than the other two. Products like 46-0-0 contain 46% nitrogen, making them extremely concentrated. A 32-0-0 has a slightly lower percentage but is often blended with slow-release technology, making it safer for lawns. The higher the nitrogen number, the more careful you need to be with application rates.
Quick Release vs. Slow Release
Quick-release nitrogen goes to work immediately — you see greener grass and faster leaf growth within days. But it can also burn plants if you apply too much or miss a watering cycle. Slow-release formulas feed plants steadily over several weeks. This is the safer option for lawns during the growing season. Some products, like liquid formulations, combine both types in one bottle to give you a fast green-up followed by sustained feeding.
Granules vs. Liquid
Granular fertilizers such as prills (small round pellets) are best for dry broadcast spreaders. They need water to activate. Liquids, on the other hand, are mixed with water and sprayed directly onto the soil or leaves. Liquids act faster because the nitrogen is already dissolved, but they require a bit more time to mix and apply correctly. Granules are the simplest choice for covering large lawns quickly.
Quick Comparison
| Model | Best For | Nitrogen (N-P-K) | Item Form | Weight | Amazon |
|---|---|---|---|---|---|
| The Andersons 32-0-0 | Lawn recovery & all-season feeding | 32-0-0 | Granules | 18 lbs | Amazon |
| Petramax Liquid 28-0-0 | Fast liquid green-up for lawns | 28-0-0 | Liquid | 32 oz | Amazon |
| Greenway Biotech Urea 46-0-0 | High-purity nitrogen for gardens & hydroponics | 46-0-0 | Prills | 2 lbs | Amazon |
| Dirty Gardener Urea 46-0-0 | High analysis crop & lawn feeding | 46-0-0 | Granules | 5 lbs | Amazon |
| The Grow Co Urea 46-0-0 | Versatile garden feeding — corn to flowers | 46-0-0 | Granules | 5 lbs | Amazon |
In‑Depth Reviews
1. The Andersons Professional Pure Nitrogen 32-0-0 Fertilizer – 18lbs
The big bag that feeds your lawn steadily without the burn risk.
This is the pick if you want one product to handle the entire growing season. It has 32-0-0 with a mix of quick- and slow-release nitrogen — the fast part greens things up in the first week, while the slow portion keeps feeding for weeks after. That two-speed approach is exactly what a healthy lawn needs: immediate color and long-term thickness. One 18-pound bag covers 6,000 square feet, which is a solid match for the average suburban yard.
The granules are intentionally small, so a broadcast spreader drops them evenly over the turf. Uneven spots lead to patchy growth, and this product’s particle size makes that less likely. Buyers report that within two weeks, their St. Augustine and Bermuda grasses turned a deep, dark green. One reviewer specifically noted that their St. Augustine grass thickened up nicely after the application.
At 18 pounds, this is the heaviest pick in the lineup — a clear 9-pound jump over the 5-pound urea bags below. It is also the only dual-release granular option here. Unlike the straight urea products that need careful watering to avoid soil dehydration, this formula is safer for any turf type, making it the most forgiving choice for someone new to high-nitrogen fertilization.
Why It Stands Out
- Quick- and slow-release nitrogen in one bag for both fast green-up and sustained feeding
- Small granule size means better, more uniform coverage from a spreader
- Covers 6,000 square feet — ideal for mid-to-large lawns
Things to Note
- Heaviest bag of the five at 18 pounds, so lifting is more effort
- Not designed for potted plants or hydroponic use — it is a lawn-first product
The season-long winner: If you want a single, forgiving, high-nitrogen feed for your lawn that gives both instant color and steady growth, this is the one to buy.
Not the right fit if: You only need a small amount for a vegetable patch or you prefer a liquid spray routine — this is a 18-pound granular bag made for spreader coverage.
2. Greenway Biotech, Inc. Urea Fertilizer Plant Food High Efficiency 46% – 2 Pounds
The purest nitrogen source — a small bag that goes a very long way.
At 46-0-0, this is the highest nitrogen concentration you will find in a home-garden product. The prills are 99.9% pure urea, sourced from Norway, and the bag is only 2 pounds. Do not let the small size fool you — one reviewer noted that it “effectively fixed nitrogen deficiency in a large garden” because the concentration is so high that a little covers a lot of ground. The recommended application rate is 2-3 pounds per 1,000 square feet for soil, or 1-2 tablespoons per gallon for hydroponics.
Because it is 100% water soluble, this product works well with both a hose-end sprayer and a watering can. It is versatile enough for lawns, but it really shines in gardens — one reviewer used it to rescue a flowerbed damaged by herbicide drift. They removed the burned leaves, applied the product, and saw new growth weeks later.
Compared to the other 46-0-0 options here, this 2-pound bag is a far smaller unit than the 5-pound bags from The Dirty Gardener or The Grow Co — a 3-pound difference in weight and a full 48-ounce gap in unit count. That makes it the best choice if you need pure nitrogen for a smaller garden or a hydroponic setup. The one trade-off: some buyers noted that the package did not include clear application instructions for direct ground use, though the manufacturer did respond quickly by email.
What Makes It Special
- 99.9% pure urea with 46% nitrogen — the highest concentration in this lineup
- Fully water soluble, so it mixes easily for sprays or hydroponic feeding
- Small 2-pound bag is convenient for targeted garden use and easy storage
Considerations
- Bag may not include full ground-application instructions; you may need to contact the seller
- Extremely high concentration means over-application burns plants quickly if you do not measure carefully
Pure power for small spaces: Reach for this if you need to fix a nitrogen deficiency in a garden bed or run a hydroponic system and want the highest purity available.
skip it if: You want an all-in-one lawn feed with slow-release technology — this is straight, fast-acting urea that requires precise application.
3. Petramax Liquid Nitrogen Fertilizer 28-0-0 NPK – 32 Oz
The liquid that turns a yellow lawn deeply green in one spray.
If you prefer a sprayable fertilizer over spreading granules, this liquid 28-0-0 is the most practical route. It uses a 2-in-1 release system: 70% of the nitrogen is quick-release for an instant color boost, and 30% is slow-release, so the grass keeps feeding between applications. Mix 5 ounces per gallon of water for routine maintenance, or 10 ounces per gallon if you are correcting a clear nitrogen deficiency. A single 32-ounce bottle can treat up to 12,800 square feet for maintenance.
The liquid form is great for even coverage — you simply attach it to a sprayer and walk the lawn. One buyer shared that they “applied 2/3 gallon to a 20x12x13 triangle with 4-6″ cheap mulch” and saw great results, noting the grass greened up fast. Another reviewer switched to a PetraTools battery-powered sprayer and reported multiple repeat purchases, which suggests the consistency works well for routine seasonal feeding.
Unlike the granular picks that require a spreader and watering-in, this bottle gives you immediate control over where the nitrogen lands. It works on all grass types, warm-season or cool-season. The trade-off is volume: 32 ounces goes further than you think, but for a large property you will need multiple bottles or a switch to the 18-pound granular option. The Andersons covers 6,000 sq ft in one bag versus this bottle’s 12,800 sq ft at maintenance rate, so the liquid actually stretches further per unit on a healthy lawn.
Why It Works
- 70/30 blend of quick and slow-release nitrogen for immediate color plus sustained feeding
- Treats up to 12,800 square feet per bottle at the maintenance rate
- Easy to use with any sprayer and works on all grass types
Watch Out For
- Liquid concentrates require measuring and mixing before each use
- You will run out faster for a large lawn in full nitrogen-deficiency correction mode (half the coverage area)
Best for the spray-and-go crowd: Grab this if you already own a sprayer and want the fastest green-up liquid on the market with a built-in slow-release backup.
Not the match if: You prefer a low-maintenance granular application and do not want to mix liquid each time.
4. The Dirty Gardener Nitrogen Fertilizer Urea 46-0-0 – 5 Pounds
Straightforward 46% nitrogen in a 5-pound bag that works in any spreader.
This is the entry-level high-nitrogen choice — no frills, just pure prilled urea with 46-0-0 analysis. The 5-pound bag is manageable for small-to-medium lawns and garden beds. Because it is a dry granular form, it spreads well with broadcast spreaders. One buyer mentioned they used it on the lowest spreader setting weekly during spring and fall and ended up with a “green thick lawn” that beat the neighbors.
There is one important catch with straight urea that The Dirty Gardener mentions clearly in the description: it tends to dehydrate the soil, so you need plenty of water after application. Without watering it in fully, the nitrogen can evaporate or burn the grass. Buyers confirm that uneven application causes patchy growth and burn spots, but when spread correctly the results are tough to top.
This product has the same nitrogen percentage as the Greenway Biotech 46-0-0 (both 46-0-0), but at 5 pounds it is a heavier bag — a 3-pound difference. That extra weight gives you more coverage per purchase. It is less expensive than the premium Andersons bag, which at 18 pounds costs more but uses a safer 32-0-0 dual-release formula. The Dirty Gardener bag is pure fast-acting urea: you get maximum nitrogen for the price, but you must manage watering carefully.
What You Get
- Highest nitrogen percentage (46-0-0) in a generous 5-pound bag
- Dry granules work well with most broadcast spreaders
- Great value for cost-conscious gardeners who can manage watering
Before You Buy
- Requires thorough watering to prevent soil dehydration and nitrogen burn
- Uneven application causes patchy growth — use a spreader, not by hand
Pick this for the budget gardener: Buy this if you have a small-to-medium lawn and are comfortable watering in your fertilizer each time to avoid burn.
Look elsewhere if: You want a slow-release, low-maintenance formula — this is pure fast-acting urea that demands attention to application and watering.
5. The Grow Co 5 lb. Urea Fertilizer 46-0-0 – High Nitrogen Fertilizer for Plants
The all-purpose 46-0-0 that pushes corn, tomatoes, and flowers into overdrive.
The Grow Co markets this as an “all purpose fertilizer,” and the reviews back it up. One reviewer described applying it “on my sweet corn at 6 inches tall and 12 inches tall” — and the result was corn stalks as big around as an arm, with leaves so green and healthy they had never seen before. Another buyer used it on tomatoes and squash and reported a big boost in growth through the season. Flowering bushes produced more blooms and healthier foliage.
The 46-0-0 ratio is the same high-strength urea as The Dirty Gardener’s bag, so the same warning applies: use it with care. The manufacturer’s instructions suggest 1/2-pound per 1,000 square feet for established turf, and 1/2 teaspoon near the drip line for vegetables, flowers, shrubs, and trees. This granular formula dissolves and is “highly soluble” according to the brand, which helps the nitrogen move into the root zone quickly.
At 5 pounds with an 80-ounce unit count, this bag weighs the same as The Dirty Gardener bag but targets a different primary audience — here the focus is on garden vegetables and flowers rather than just lawns. The Greenway Biotech 2-pound bag is the better choice if you only need a small amount for a specific deficiency. The Grow Co bag is the better pick if you want to feed a large garden plot and multiple planting rounds through the season.
What Works Well
- 46-0-0 formula proven to boost sweet corn, tomatoes, squash, and flowering plants
- Easy-to-follow application rates: 1/2 lb per 1,000 sq ft for turf, 1/2 teaspoon per plant for gardens
- Highly soluble granules for quick absorption into the soil
Keep In Mind
- All the burn risk of a high-concentration urea — do not over-apply
- Not ideal for large lawns; the 18-pound Andersons bag covers more ground per purchase
Top pick for vegetable growers: Reach for this if you want a proven high-nitrogen feed for sweet corn, tomatoes, flowers, and shrubs that delivers fast, measurable results.
Give it a pass if: You need a slow-release lawn formula — this is straight 46-0-0 urea that requires careful measurement and consistent watering.
Understanding the Specs
N-P-K Ratio: The First Number Tells the Story
The three numbers on a fertilizer bag represent nitrogen (N), phosphorus (P), and potassium (K). A high nitrogen fertilizer like 46-0-0 has 46% nitrogen by weight and zero phosphorus and potassium. The higher the first number, the more concentrated the product. A 32-0-0 is still high in nitrogen but has a wider safety margin than 46-0-0. For lawns, a ratio like 32-0-0 or 28-0-0 is common. For a quick green-up on vegetables, 46-0-0 prilled urea is the standard choice — but you must use less of it.
Quick Release vs. Slow Release: Speed vs. Safety
Quick-release nitrogen is immediately available to plants. You see results in days, but it can burn if applied heavily or left dry. Slow-release nitrogen breaks down over weeks through microbial action or a coating on the granule. Products like the Petramax liquid 28-0-0 combine both: the fast portion green things up now, and the slow portion keeps feeding between applications. Granular products like The Andersons 32-0-0 also use a dual-release mix. Pure urea (46-0-0) is entirely quick-release — it works fast but demands careful watering.
FAQ
Can I use a 46-0-0 fertilizer on my lawn?
What is the difference between pure urea and a 28-0-0 liquid fertilizer?
How often should I apply high nitrogen fertilizer to my lawn?
Will high nitrogen fertilizer burn my plants?
Can I use high nitrogen fertilizer on vegetables like tomatoes and sweet corn?
What does 32-0-0 mean on a fertilizer label?
How do I apply granular high nitrogen fertilizer?
Is liquid or granular high nitrogen fertilizer better?
Can I use high nitrogen fertilizer in a hydroponic system?
How do I store high nitrogen fertilizer safely?
Final Thoughts: The Verdict
If you want one dependable pick, the high nitrogen fertilizer winner is the The Andersons 32-0-0 because its dual-release blend gives you the fastest green-up without the burn risk of pure urea. If you prefer a liquid spray that works on all grass types and stretches further per bottle, grab the Petramax Liquid 28-0-0. And for the most concentrated, pure nitrogen fix in a garden bed or hydroponic setup, the standout is the Greenway Biotech 46-0-0.
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.
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