Last updated: July 27, 2026
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The short version
After researching the certifications, ingredients, and performance of the most popular organic fertilizers, our top pick is Dr. Earth All Purpose (5-5-5). It is OMRI-listed, feeds through a rich blend of natural ingredients and beneficial microbes, and works across the whole garden, which is why it earned our highest Organic Integrity Score of 92 out of 100. For the best value at garden centers everywhere, Espoma Plant-tone is our pick, and for a fast-acting liquid feed, Neptune’s Harvest Fish & Seaweed is the best choice.
The key certification here is OMRI Listed (Organic Materials Review Institute), which verifies a fertilizer is allowed in certified organic growing. We flag which products are OMRI-listed and note their NPK (nitrogen-phosphorus-potassium) numbers. Scores below run from our 92-point top pick to the 72-point value option.
Key benefits of organic fertilizer
Fertilizer is how you feed your plants, and how you feed them shapes the soil for seasons to come. Choosing an OMRI-listed organic fertilizer feeds the soil, not just the plant. Here is what that gets you.
1. Slow, steady release
Organic fertilizers break down gradually through soil microbes, so plants get consistent feeding without the boom-and-bust of synthetic salts, and far less risk of burning roots.
2. Feeds the soil biology
Ingredients like bone meal, kelp, and alfalfa feed earthworms and microbes, building fertile, living soil over time instead of depleting it.
3. Less runoff and burn
Because nutrients are released slowly and bound in organic matter, less leaches away into waterways, and there is less risk of over-application damage.
4. Safe around edibles, kids, and pets
OMRI-listed fertilizers are made from natural ingredients, which many families prefer for vegetable gardens and yards used by children and pets.
Organic vs synthetic fertilizer: does it matter?
Synthetic fertilizers deliver a fast, concentrated hit of nutrients, but that same solubility is why they leach into groundwater and rivers, can burn roots when overapplied, and feed the plant while doing little for the soil. Over years, soils fed only on synthetics tend to lose organic matter and biological life.
Organic fertilizers work with the soil instead: microbes convert the natural ingredients into plant-available nutrients on demand. The environmental case is concrete, from the NOAA-monitored Gulf dead zone driven by nutrient runoff to the steady decline of soil carbon under intensive synthetic use. Our scoring weights certification and soil-building value alongside real-world results, because a fertilizer that does not actually grow strong plants is not worth using.
How to choose an organic fertilizer
- Look for the OMRI seal. It is the verified standard that a fertilizer is allowed in certified organic growing.
- Read the NPK numbers. Leafy growth wants more nitrogen (the first number); flowers and fruit want more phosphorus and potassium. Match the blend to the crop.
- Granular vs liquid. Granular feeds slowly over weeks; liquid (like fish emulsion) acts fast and is great for a mid-season boost or seedlings.
- Check for added microbes. Blends with mycorrhizae or beneficial bacteria help roots take up more of what you apply.
- Consider the smell. Fish- and manure-based fertilizers can smell strongly; plant-based blends are milder for indoor or patio use.
Who this guide is for
The best fertilizer depends on what and how you grow. If you want the best all-around granular feed, our top pick fits. If you want the easiest to find, a fast liquid boost, a value granular, or single-ingredient control over your blend, we have a pick for each.
Our top organic fertilizers at a glance
| Best Choice | Best Value | ||||
| Product | Dr. Earth All Purpose | Espoma Plant-tone | Neptune’s Harvest | Jobe’s Organics | Down to Earth |
| Organic Integrity Score | 92/ 100 | 87/ 100 | 82/ 100 | 77/ 100 | 72/ 100 |
| Best for | Best overall | Availability | Liquid feed | Value granular | Custom blends |
| Certification | OMRI Listed | OMRI Listed | OMRI Listed | OMRI Listed | OMRI Listed |
| Form | Granular | Granular | Liquid | Granular / spikes | Granular, single-source |
| Price | Check price | Check price | Check price | Check price | Check price |
Scores are ours, based on independent research of certification, ingredient quality, soil-building value, and results, using the same 10-criteria method we apply to every product.
Best overall: Dr. Earth All Purpose (5-5-5)
| Organic Integrity Score | 92 / 100 |
| Certification | OMRI Listed |
| NPK | 5-5-5 balanced |
| Best for | Vegetables, flowers, and general feeding |
Dr. Earth All Purpose is our top pick because it is a complete, balanced feed that also builds soil. The OMRI-listed 5-5-5 blend combines fish bone meal, alfalfa, kelp, and other natural ingredients with the brand’s TruBiotic beneficial microbes and mycorrhizae, and its balanced NPK works across vegetables, flowers, and shrubs.
The trade-off is that, as a rich organic blend, it can attract curious pets to a freshly fed bed and costs a bit more than basic granulars. For an all-around organic fertilizer that feeds plants and improves soil, it is our first choice.
What we liked: OMRI-listed, balanced 5-5-5, rich natural ingredients plus beneficial microbes and mycorrhizae, and genuinely all-purpose.
Keep in mind: The fish and bone ingredients can attract dogs to a freshly fed bed, so work it in well, and it costs more than basic granulars.
What buyers say: Gardeners report strong, steady growth across many plant types and value the microbe content. A few mention working it into the soil to keep pets from digging.
Best value: Espoma Plant-tone
| Organic Integrity Score | 87 / 100 |
| Certification | OMRI Listed |
| NPK | 5-3-3 all-purpose |
| Best for | An easy-to-find certified granular at a fair price |
Espoma Plant-tone is our value pick and a classic for good reason. It is OMRI-listed, enhanced with the brand’s Bio-tone beneficial microbes, and sold at practically every garden center and hardware store at a low price. The Espoma “-tone” line also offers crop-specific blends like Tomato-tone and Holly-tone.
It scores just below our top pick on the richness of its ingredient blend, but as a reliable, widely available certified granular, it is the easiest to buy and the best value.
What we liked: OMRI-listed, Bio-tone microbes, a whole family of crop-specific blends, and unbeatable availability at a low price.
Keep in mind: The all-purpose blend is milder than our top pick, so heavy feeders may want a crop-specific “-tone” version.
What buyers say: A longtime gardener favorite for reliable results and easy availability. Some step up to Tomato-tone or Garden-tone for hungry crops.
Best liquid feed: Neptune’s Harvest Fish & Seaweed
| Organic Integrity Score | 82 / 100 |
| Certification | OMRI Listed |
| Form | Liquid concentrate (dilute and apply) |
| Best for | Fast feeding, seedlings, and foliar spray |
Neptune’s Harvest is our pick for a fast liquid feed. This OMRI-listed fish and seaweed emulsion delivers quickly available nutrients and trace minerals, ideal for giving seedlings, transplants, and mid-season plants a rapid boost, and it can be used as a soil drench or foliar spray.
It scores in the middle mainly on the strong fish smell and the need to reapply more often than granulars, but for fast, gentle feeding it is one of the best liquids available.
What we liked: OMRI-listed, fast-acting fish and seaweed nutrients plus trace minerals, versatile as a drench or foliar spray, and gentle on seedlings.
Keep in mind: It smells strongly of fish when applied (the smell fades), and being liquid it needs reapplying every couple of weeks.
What buyers say: Growers love the quick green-up on seedlings and containers. The recurring note is the fish odor, which most say dissipates within a day.
Best value granular: Jobe’s Organics
| Organic Integrity Score | 77 / 100 |
| Certification | OMRI Listed |
| Form | Granular or fertilizer spikes |
| Best for | Affordable feeding, including trees and shrubs |
Jobe’s Organics is our value granular pick. It is OMRI-listed, includes the brand’s Biozome microbe package to break down nutrients, and comes in both granular bags and convenient pre-measured spikes for trees, shrubs, and container plants, at an affordable price.
It scores in the value range on ingredient richness versus the leaders, but for an accessible certified granular, and especially for the no-mess spikes, it is a practical everyday option.
What we liked: OMRI-listed, Biozome microbes, an affordable price, and handy spike formats for trees, shrubs, and pots.
Keep in mind: The blend is simpler than our top picks, and like all fish- and manure-based organics it can have an earthy smell when first applied.
What buyers say: Buyers like the price and the convenience of the spikes for shrubs and houseplants. Some prefer a richer granular for vegetable beds.
Best for custom blends: Down to Earth
| Organic Integrity Score | 72 / 100 |
| Certification | OMRI Listed (most products) |
| Form | Granular blends and single ingredients |
| Best for | Gardeners who want to build their own program |
Down to Earth is our pick for gardeners who like control. It offers OMRI-listed all-purpose blends plus a wide range of single-ingredient amendments (blood meal, bone meal, kelp, langbeinite) in compostable boxes, so you can build a fertilizer program tailored to your soil test and crops.
It scores at the value end here on plug-and-play convenience rather than integrity, since it rewards a bit of knowledge, but for quality ingredients and customization it is a favorite of experienced organic growers.
What we liked: OMRI-listed quality, a huge range of single ingredients for custom blends, and plastic-free compostable boxes.
Keep in mind: Getting the most from it rewards knowing your soil and crop needs, so it suits hands-on gardeners more than beginners wanting one bag.
What buyers say: Experienced gardeners love the ingredient quality and packaging. Beginners sometimes prefer a ready-made all-purpose blend to start.
How to use organic fertilizer well
Work granular fertilizer into the top inch or two of soil and water it in, so microbes can start converting it. Feed at planting and then every four to six weeks for heavy feeders, since organics release slowly. Use a liquid feed like fish emulsion for a fast mid-season boost or for seedlings. A soil test takes the guesswork out of which nutrients you actually need, and prevents over-application, more is not better with fertilizer.
How we researched this guide
We are a research-based review site. We did not lab-test these fertilizers ourselves. We compared each against its OMRI listing, ingredient disclosures, NPK values, and the weight of aggregated gardener feedback on results, then scored each with our 10-criteria Organic Integrity Score. No brand paid to be included or ranked. Read the full method on our How We Research and Rate page.
Frequently asked questions
What is the best organic fertilizer?
Our overall pick is Dr. Earth All Purpose (5-5-5), because it is OMRI-listed, feeds through rich natural ingredients and beneficial microbes, and works across the whole garden. For the best value, Espoma Plant-tone is our pick.
What do the NPK numbers mean?
NPK stands for nitrogen, phosphorus, and potassium, the three numbers on a fertilizer label. Nitrogen drives leafy growth, phosphorus supports roots and flowers, and potassium supports overall vigor and fruit. Match the ratio to your crop.
Is organic fertilizer better than synthetic?
For soil health and reduced runoff, yes. Organic fertilizers release nutrients slowly through soil biology, build organic matter, and are far less likely to burn plants or leach into waterways than fast-dissolving synthetic salts.
How often should I apply organic fertilizer?
Because organics release slowly, feed at planting and then every four to six weeks for heavy feeders during the growing season. Liquid feeds act faster and can be applied every couple of weeks for a boost.
Does organic fertilizer smell bad?
Fish- and manure-based fertilizers can smell strongly when first applied, though the odor usually fades within a day. Plant-based blends are much milder and better for indoor or patio plants.
Related reading
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