Reader support helps keep the reviews honest and the site humming. As an Amazon Associate, I earn from qualifying purchases.7 Best Nitrogen Fertilizer For Vegetables | 46-0-0 vs 21-0-0

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The Ammonium Sulfate 21-0-0 earns the top spot because it delivers a strong 21% nitrogen punch while also bringing 24% sulfur — a combination that both feeds your vegetables and gently lowers soil pH for plants that prefer slightly acidic conditions. Compared to the straight 46-0-0 urea options, this is more forgiving and offers a built-in pH adjustment. One buyer reports their “peppers and tomatoes were struggling to grow last season… within a few days plants were bright green and growing amazing,” which matches the fast-acting granular formulation. The 4-pound bag covers 100 square feet easily, and the sulfur content is a genuine bonus if your soil leans alkaline (high pH), helping unlock other nutrients your vegetables need. At this mid-range price point, you get two soil benefits — nitrogen feeding and pH correction — in one product.

The one honest limit is that ammonium sulfate can acidify soil more than other nitrogen sources, so you should test your pH if you plan to use it season after season. If your soil already runs acidic (below 6.0), this may require occasional lime to balance things. For most vegetable growers on neutral or alkaline soil, this is simply the most practical all-rounder you can buy. If you want a fast, safe nitrogen boost for tomatoes and peppers without the burn risk of 46-0-0, this is your pick — but skip it if your soil is already acidic.

For vegetable gardeners on neutral or alkaline soil, this is the most practical all-rounder you can buy.

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Compared to the top pick’s 21-0-0 Ammonium Sulfate, this urea fertilizer jumps to a massive 46-0-0 ratio — more than double the nitrogen concentration — so you need far less product to achieve the same green-up effect. That extreme potency makes it a specialty tool rather than an everyday fertilizer: it is the best choice for rescuing pale, nitrogen-starved vegetable beds or feeding heavy feeders like corn, but it requires careful handling because getting the dose wrong can burn foliage and roots quickly. One buyer reports applying it “weekly in the spring and fall on the lowest spreader setting” for an “amazingly green thick lawn,” and the same principle applies to vegetables. The 5-pound bag of pure prilled urea (small, granular pellets) spreads easily in most broadcast spreaders, and because it is straight nitrogen with zero phosphorus or potassium, you maintain complete control over your soil’s N-P-K balance.

Urea’s 46-0-0 ratio means a single pound delivers more than twice the nitrogen of a pound of 21-0-0, so you measure by the tablespoon rather than the cup. This concentration demands precise application: over-apply by even a small margin and you risk yellowing leaf tips or root damage, especially in hot weather. For vegetable gardeners, it works best as a side-dressing for heavy feeders like sweet corn or as a rescue treatment for pale, nitrogen-deficient beds, but it should never touch wet foliage or sit in a pile on the soil.

Choose this over the top pick if you already understand nitrogen burn risks and you want the fastest, most concentrated nitrogen boost possible for crops like sweet corn, leafy greens, or spring brassicas. For anyone uncertain about measuring tiny amounts precisely, the 21-0-0 option is more forgiving and safer for general vegetable use.

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If you are growing sweet corn, tomatoes, or squash and want to see dramatic results fast, this high-nitrogen urea is purpose-built for those hungry crops. One buyer applied it to their sweet corn “at 6 inches tall and 12 inches tall” and reports “I have never had such big beautiful corn. The stalks are as big around as my arm.” That kind of testimonial tells you this is serious fuel for heavy feeders that demand steady, strong nitrogen during their rapid-growth phase. The 46-0-0 ratio provides nearly half its weight in pure nitrogen, so a little goes a long way — the manufacturer recommends just 1/2 teaspoon near the drip line for vegetables. The prilled granules (small, uniform pellets) are highly soluble and quickly absorbed, so you see greener leaves and faster growth within days of application.

Gardeners with small raised beds or container vegetables who need precision should stick with the 21-0-0 Ammonium Sulfate instead, since it is harder to over-apply. But if you are growing corn, pumpkins, or other heavy feeders that demand the highest nitrogen concentration available, this is the product you want in your shed.

The 5-pound bag at 46-0-0 delivers more nitrogen per dollar than just about any other option on the list.

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The single number that matters most to tomato and zucchini growers is 19% — the calcium content in this calcium nitrate fertilizer. Blossom-end rot (that black, leathery spot on the bottom of your tomatoes) is almost always a calcium deficiency, and this product delivers 15.5% nitrogen plus 19% calcium in one water-soluble, greenhouse-grade formula. One reviewer noted it “fixed blossom end rot in bucket-grown tomatoes within 1.5 weeks via foliar spray and watering,” which is about as fast a fix as you will find. The catch you accept is that this is not a high-nitrogen fertilizer in the traditional sense — the 15.5-0-0 ratio is moderate compared to 46-0-0 urea, so if your primary need is just a nitrogen boost for pale leaves, the sulfur-free formula will green things up but not as explosively as the higher-N options.

However, if you are dealing with blossom-end rot, the calcium makes this product indispensable. It is also 100% water-soluble (greenhouse grade), meaning no oily residue left in your irrigation equipment. For the vegetable gardener growing tomatoes, peppers, zucchini, or squash in containers or raised beds — where calcium leaches out through drainage holes — this is the most cost-effective way to prevent blossom-end rot and feed nitrogen simultaneously.

If you don’t have blossom-end rot issues, the 21-0-0 Ammonium Sulfate delivers more nitrogen for less money, which gives this product a price-to-value read that depends entirely on whether you need that 19% calcium fix.

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What you actually get at this lower price is a 16-ounce container of 14-0-0 plant-based nitrogen powder that delivers 18 L-Amino Acids—protein building blocks that boost chlorophyll concentration and photosynthesis for greener leaves without the harsh chemical shock of synthetic urea. Buyers report it “works faster than expected; plants visibly greener and growing more robustly within a day.” The downside for this gentleness is lower raw nitrogen power than a 46-0-0 urea, meaning you need more product per application, and the small container is designed for targeted use rather than covering large vegetable beds.

The powder dissolves 100% in water and can be applied as a foliar spray directly onto leaves for near-instant nitrogen absorption. It also acts as a chelating agent to help plants absorb micronutrients more efficiently, pairing well with other organic fertilizers. This is the perfect choice for the organic-minded vegetable grower who grows from seed and wants a reliable, non-burning nitrogen boost for seedlings or container vegetables.

Gardeners with large in-ground beds will get more value per dollar from the Down To Earth Feather Meal, making this product the exact budget buyer it is perfect for: the small-scale or container grower who prioritizes gentle, fast-acting organic nitrogen over volume and cost-per-pound.

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Espoma’s Blood Meal is perfect for the organic vegetable gardener who wants a 100% natural, OMRI-listed nitrogen source that also repels deer and rabbits. With a 12-0-0 ratio from all-natural domestic blood meal and no fillers, it feeds nitrogen while its scent deters pests around tender plants. The 3-pack provides three 1-pound bags (48 ounces total) for convenient portioning, and long-time users say it “gets results” when mixed with bone meal for a complete feeding program.

One honest limit: blood meal has a strong, distinctive odor (it is dried animal blood), and some gardeners find the smell unpleasant during application. Also, the 12-0-0 ratio means you need more product by volume compared to synthetic 46-0-0 options, so for very large gardens the cost per application is higher. If you are committed to organic methods and want a trusted brand with a century-long reputation (since 1929), this is your pick.

For bulk organic nitrogen that goes further, the Down To Earth Feather Meal offers better value per pound — but a gentle caution: blood meal’s strong scent can attract unwanted attention from dogs or wildlife if not worked into the soil immediately, so always water it in right after application.

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Compared to the rest of the field, the Down To Earth Feather Meal delivers the most nitrogen per dollar — a 20-pound bag of OMRI-listed, slow-release organic fertilizer at a lower per-pound cost than any other product in this guide. The 12-0-0 formula comes from ground and hydrolyzed poultry feathers, providing a steady supply of nitrogen that won’t burn plants, even if you accidentally apply a bit too much. What that money actually gets you is a season’s worth of organic nitrogen for heavy feeders like corn, tomatoes, and fall-harvested vegetables. The slow-release mechanism means microbes in warm, moist soil gradually break down the feather meal, releasing nitrogen over 4-6 weeks rather than all at once. Owners mention it “worked great in the garden” and it doubles as an effective deer repellent — one buyer mentioned “product on leaves does not dissolve” but that it “is excellent deer repellent for weeks” protecting hostas, tulips, and lilies.

The one reason to choose this over the Espoma Blood Meal is scale. If you are managing a large vegetable garden, a 20-pound bag of slow-release organic nitrogen that lasts an entire growing season and costs less per pound than any other organic option is simply unbeatable value. Be aware that the smell is strong — described as “extremely foul” and “unbearable” by some reviewers — so store it in a sealed container away from your house. Gardeners with small raised beds who want faster results should pick the 21-0-0 Ammonium Sulfate instead.

The one clear reason to choose it is scale: a 20-pound bag of slow-release organic nitrogen that lasts an entire growing season and costs less per pound than any other organic option here.