Is 10-10-10 Fertilizer Really The Best Garden Choice?

10-10-10 fertilizer is one of the most popular fertilizers.

This week, I received a great question about the nutritional difference between 10-10-10 and compost:

Most bags of compost and manure say they have about .1-.1-.1 of the big 3. I have tested my own compost and it is somewhat higher but still not in the 10 10 10 range recommended for most plants. So, how do you get enough without using fertilizers? Is 10-10-10 the same as .1-.1-.1? Am I missing something?

I’m glad you asked. There are 3 things I’d like to address…

10-10-10 Fertilizer

1. Fertilizer Labels

In many countries, in order to be considered a fertilizer, a product must contain a minimum percentage of total nitrogen, available phosphate and soluble potash.

They’re written on the label as 10-10-10 fertilizer or 5-10-5 fertilizer or whatever.

But the percentage that’s required in order to be labeled a fertilizer can be quite high, in some cases over 20%.

Notice that it’s available phosphate and soluble potash, not total.

This has an unfortunate consequence for organic fertilizers because nutrients in organic fertilizers are wrapped up in various organic compounds that need to be broken down by microbes before they become available to plants.

That’s how nature does it, but it takes time, so most of these nutrients are not so quickly “available.”

That means much of the NPK in these fertilizers doesn’t get counted on the label, which means many fertilizers used in organic gardening don’t qualify as a fertilizer.

They look like poor value when compared to the high numbers of chemical fertilizers, even if the organics will supply more nutrition over time.

With the low NPK numbers, they end up being sold as soil amendments or perhaps specialty fertilizers.

That’s why things like compost and kelp aren’t technically “fertilizers.” For example, the seaweed fertilizer I use is only a 0-0-1.

2. What Is A Complete Fertilizer?

Further, the law says a “complete fertilizer” only has to supply these three nutrients.

We know, of course, that plants need 17 nutrients (and probably benefit from many more than that), so it makes no sense to apply only three.

In fact, applying too much of these three indiscriminately often causes problems.

That’s one reason why quality compost and biostimulants like sea minerals are often the best garden fertilizer choices – they supply everything in small amounts, which ensures all of the nutrients are covered.

3. How Much Of Each Nutrient Does A Plant Need?

Now, onto your specific questions.

No, 10 10 10 fertilizer is not the same as .1-.1-.1. It contains 100 times more total nitrogen, available phosphate and soluble potash.

And when you mentioned that your compost doesn’t reach the 10-10-10 range recommended for most plants, the truth is that range isn’t really recommended for any plant – it’s just something fertilizer manufacturers came up with.

You asked how to get enough nutrients without using fertilizers, and the heart of the question is really, “how much of each nutrient does a plant need?”

The answer is shockingly little. Only tiny amounts of each nutrient are actually removed from the soil when we harvest the vegetable garden. We’re talking grams of each nutrient.

If our soil is poor and losing nutrients through leaching and volatilization, we need to add a little more than if we have a balanced, sustainable ecosystem, but not nearly as much as one might think.

10-10-10 Fertilizer Summary

The bottom line is:

  • Fertilizer labels are misleading, implying that plants need high amounts of just NPK – plants need many more nutrients than NPK, and they need very small amounts of each.
  • The chance that your plants and soil will be happy with 10-10-10 fertilizer is low.
  • Well-made compost and biostimulants are some of the best fertilizer choices for supplying what plants really need.
  • If you want to know how to fertilize properly, this article goes into more detail.

Any questions or comments about 10-10-10 fertilizer? Let me know below.

54 Comments

  1. So are we to focus on feeding the microbes in the soil so that they can do their work in feeding our plants?

    1. Barry hocking says:

       Yep true feed the soil not the plants. Different plants have different requirements.

  2. Djejenkins says:

    Thanks for answering my question! Very enlightening

  3. Africanaussie says:

    I was just adding compost , fresh seaweed etc to the garden, but felt there was not enough fruiting a flowering.  Lately I am adding just a touch of sulphate of potash to a foliar feed every couple of weeks and have noticed a marked improvement.  Also trace elements seem to be lacking in our soils.   We have such high rainfall during the wet season that i think these need to be replaced now at the beginning of the dry season.  I am thinking that each area is different and the longer you live in an area the more you understand each particular area.   Definitely agree with little bits of everything more often, and then see how things go before adding more..

    1. That’s interesting – I wonder why the sulphate of potash is encouraging flowering/fruiting. Perhaps you’re low in sulphur or potash or maybe it’s just the energy boost they need.

      1. Karen Gouvas says:

        I use it as a boost, i watch Gardening Australia who discussed using it to sweeten the flavor of tomatoes, i’m trying it on cherry tomatoes, yet to eat one

        1. Baking soda sweetens them up nicely

  4. Hey Phil,So here in the states, NJ to be specific, the gardening season is cranking along. I only started my 1000 sq ft garden this year. Tilled up my lawn and left all the chopped up grass in there. I thought I would have soil issues but I guess not. i did pick out large grass clumps and have a compost pile going.So no tests on the soil and am just winging it. I did get out of your site the mycorrhizae concept, and gardening all organic.So I wish to show you what I feel is good for being all organic, and please critique as needed.First off here is what I have so far.I have a identical plot on the backside yard with the same dimensions. You can see I added irrigation risers for watering. Coming from the well with a PH of the water at about a 6.0. There is nothing I can do about that.You see I have lettuce, cabbage, celery already growing good. I have had several salads already and am following a continuous harvest plan. I just transplanted the tomato’s and peppers, more celery and parsley. Beets and carrots are growing good, and chard is just sprouting.Now what I use? And this is all I have been doing 100%I have been using this to prep the soil before seeding and transplants.Dr Earth. 5 7 3 ( No GMO, sewer sludge, or poultry manures. Has mycorrhizae in all his products.I sprikle it on the soil and rack it in the top 4″ I only pitch fork the soil and lift it for aeration. ( There are many worms in the soil and I though from me tilling these section hat I messed up the soil. I have been also spraying this at the recommended 1 oz per gallon as a foliage and soil drench every two weeks or so. As far as pesticides and fungicides I have not had any issues yet except for my apple tree with Caterpillar, and my beets may have a fungus because of leave spots. Some cabbage leaves have also had some worm/Caterpillar damage.I use this. Organocide OMRI approved. I used the 3 in 1 and worm and Caterpillar.I did use the mycostim during my first plantings but the stuff was $$$ and I thought it was better to get the DR earth stuff that has it in it and is a fertilizers.Oil based products. So from what I learned from your site is feed a little at a time is better then a lot at once. I believe I am feeding properly because everything is growing fine.What do you think of the products I use and how I am applying Them?Any advice you can give would be appreciated.Also no offense Phil but your academy is a bit pricey for a per month bases. I am not sure what you are offering in addition to what you already have on your site but it does not seem cost effective. Possibly a yearly membership at $70 usd would be more in line. people dont want monthy bills with this economy like it is and need some kind of value for thier money.Just my opinion.A smart guy like you should venture into what this lady is doing in my area. She gets $45 an hour for consulting from what I hear. She has other packaged where she will set up your garden for you and teach you every step of the way.She comes to your house with raised beds and such and gets you going. OK Phil thank you for helping me and I hope I may have helped you in return somewhat.Regards,Mike L. New Jersey USA

    1. Hi Mike, seems like you have a good start there. A mulch layer would be your friend. I only comment on specific products for Academy members, because it takes some research on my end to figure out if a product is good. It seems you’re on the right track – the success rate will depend on the balance of nutrients in your soil (especially calcium) and the humus. I’m not a huge fan of BTK for insect control, but it is certainly allowed.Thanks for your thoughts on the Academy. Obviously there will always be some people who think a product or service is too expensive, which is understandable. I’m getting lots of incredible feedback from members, so there must be something right going on there. As for what’s different about the Academy and this site – in the Academy you get 35-40 videos per month covering topics in great detail, while on this site I post 1 article or video every week or two.Hope you have a great gardening year!

  5. My previous comment was not posted I believe. Wonder why? Something about a moderator had to review it….LOL

    1. Ya, it was automatically flagged because of the links, so I had to manually approve it.

  6. Ramana Peddu says:

    Does sea minerals fertilizer have all the minerals that are in sea kelp fertilizer?

    1. Yes, and probably more.

  7. Robert Pavlis says:

    A lot of good info here, but the comment “plants prefer their nutrients in organic form, prepared by microbes” is incorrect. plants can’t tell the difference between nutrients from commercial fertilizer and an organic source because they are exactly the same. See http://www.gardenmyths.com for more details on this common myth.

    1. Ya, I was rather loose on my word choice there – what I mean is that toxic fertilizers like urea formaldehyde and triple superphosphate and potassium chloride often damage the soil’s chemical and biological balance. When the chemistry gets imbalanced, nutrients get tied up and soil structure is damaged. When soil biology is killed, the plants don’t get the benefits from that biology – minerals, vitamins, water, defense against predators, soil building, etc.What I should have said is that plants are healthiest when they have a healthy soil food web to work with, so let’s not hinder these natural processes in favor of force feeding the plants directly with just 3 nutrients.

  8. Larry Riley says:

    I just returned from a feed and seed mill . I have a few peach trees a few pecan trees,so I asked google how best to take care of them and was told by google to use a certain amount of nitrogen the first time and adding more as my trees grew older. Well I asked at the seed mill about this and they said no,no,no,use 10-10-10 for your fruit and nut trees! I’m also growing tomatoes and cucumbers and all the bag of 10 10 10 it has a picture of beautiful tomatoes. What is going on! Should I use 10 10 10 for my fruit trees and nut trees? Also for my vegetable garden. I am now more confused than ever HELP HELP! !!!!

    1. Unfortunately, it’s a little more complicated than saying one fertilizer is better than another when it comes to fruit and nut trees. Ultimately, it depends on what is going on with your soil. Here’s my main fertilizer page where I discuss organic fertilizers in general: https://www.smilinggardener.com/sale/organic-fertilizers/

  9. CT Organic says:

    I add some ashes from my wood stove into my garden plot in the winter, coffee grinds in the spring an fall, along with home made compost, organic grass fed manure, worm castings, and I till in baby rye/wheat in September

  10. Hi, I am working in my forest area where the forest floors have not been disturbed for over 25 years. I try to maintain a natural for the animals and birds. I have made a trail to the area where I am viewing area. I am trying to limit disruption (damage) the pristine environment. I was thinking of fertilizing the area I have compressed and broke down to help the area return it to its’ original condition. Some plants are sword ferns, firs, cedars, moss, rhodies, berries, birches, daffodils, small leafy bushes, etc. I live in the NW .Any education or advice would be greatly appreciated .Doug.

    1. I wouldn’t suggest any fertilizer – just leaves. It sounds like you’ve done minimal damage, so the forest will fix it over time.

      1. Thank you for your time and advise.Doug

  11. only126db says:

    I started my first container grow of hot peppers (just did final harvest) and used a 10-10-10 fertilizer and from what other growers expressed I did quite well. Now my problem is that it seems I can no longer get the fertilizer I had used. Time to try something different…..

  12. Erin Davila says:

    What do you suggest for canna lilies then?

    1. Well it depends on the fertility of your soil, as every soil is different, but good compost will go a long way, and then monthly fertilizing with liquid fish fertilizer or sea minerals should have you covered.

    2. Louise Chase says:

      What do you recommend for an established grape arbor in hard soil?

      1. I don’t really recommend specific fertilizers for specific plants. I mainly apply specific nutrients to balance out the soil based on a soil test, and then I apply broad-spectrum nutrients that can benefit all plants (like seaweed and sea minerals).

  13. Garrett Jon Parker says:

    This will be my first year doing a vegetable garden at our local community gardens. The plots are going to be fertilized with 10-10-10 fertilizer. What can I add to the soil to give the plot a better chance?
    Thank you for any advice…

  14. Mark Newton says:

    I had a garden in the front yard that was doing ok, my wife didn’t like the looks of it for people driving up, so I moved it to the back the house not thinking it would do as well, to my surprise it produced twice what the other garden did, but after 3 years it didnt seem to produce as well, and seems to be lacking something. I tried 10/10/10 and it seemed to produce a lot of green plants but no abundant fruit. Beets had great leaves but small beets, tomatoes had 5 ‘ plants but fruit was small and not abundant, what is this garden missing? I have a lot of clay soil, have added sand , buried leaves from previous year, added manure from Walmart, added topsoil from Walmart, soil is not black but brown looking, Help

    1. Sand won’t generally help much, nor topsoil. Burying leaves can cause some problems in the short term, but should be helpful in the long term. Same with manure. But other than that, it’s hard for me to say what’s wrong. Sending a soil sample to a good organic lab and getting recommendations from them would give you some clues as to which nutrients are deficient/excessive.

    2. crazysquirrel says:

      Be careful with Walmart compost and manure.
      It says organic on the front, but if you read the back, it says not for organic gardening.
      Go figure.

      If you want to compost leaves, you need to add a nitrogen source in with them.
      Used coffee grounds are EXCELLENT for that purpose.

      Your goal I think is something like 30:1 leaves to coffee grounds.
      Elsewhere I read 20:1

      Worms LOVE coffee grounds.
      BUT, so do GRUB WORMS.

      It will take 6 months to a year to compose them, unless you use a compost barrel (turns smaller quantities of the mix with hand crank or electric motor).
      Compost barrel (kind that turns) can make compost in 3-6 weeks.

      If you want to amend your soil, look into worm castings.

      Oh and pouring some molasses onto the pile and mixing in will speed things up. Must be sulfur free molasses.

      In a pinch you can use table sugar but that tends to draw flies and other bugs.

      Small beets and tomatoes may indicate a lack of phosphorous (middle number).

      Perhaps you can contact your local extension office and do a full soil test (not just the basic one but a full one).
      It can reveal a LOT about what is in your soil, how much, and what you may be lacking.

      Fun fact: American Indians used to dig a hole, put a fish in it and 5 kernels of corn, then cover the hole.

  15. Rose Ann Sabas says:

    10-10-10 fertilizer is really an organic? 10-1010 fertilizer was made from what organic matter ?
    what are the organic contents and active ingredients ?

    thank you

    1. No, it’s not organic.

  16. Hello
    What is better for gardening. Composting in a composed bin or direct composting meaning that you add your vegetable scraps directly into the soil and Let it breakdown by the microorganisms?

    1. Good question. I don’t know that there’s a correct answer here, as there are advantages to each.

  17. Alan Reubel says:

    What is the best fertilizer % for evergreens on Long Island NY….probably won’t do soli testing and ready to apply. Also, when to ppaly in Fall & Spring ?

    Many Alan thanks…..

    1. Of course, it depends on your soil, but in general for evergreens I say don’t apply too much. Compost may be sufficient. If you don’t have compost, something broad spectrum like rock dust, alfalfa meal or fish meal could bring some benefit.

    2. crazysquirrel says:

      In areas with acid rain, you may need to add in Epsom Salts to your watering or sprinkle around the drip line.

  18. Burning leaves, dried tree limbs, grass clippings , and any other sort of organic material will help you grow. Not sure it’s a replacement for 101010 but at the prices bags of fertilizer goes for these days I would burn anything dropping on your property and throwing it into your garden soil.

  19. Samuel Hay says:

    10-10-10. Minute amounts are ideal. If you add a little more the plant will ignore it. Too much and you have a problem. The others that are absolutely necessary are Boron, manganese, Iron, zinc and copper. I tried Deer Minerals but after reading the bag I only applied a minute amount. It seemed to be a reasonably priced product for the purpose. Problem is that it is primarily salt!
    So what is the solution? Very simple actually, go to a discount store like Dollar General. They stock all these minerals for human consumption at prices you can afford. Get a five gallon bucket, my preference is a plastic fuel can, and after running them all through your blender, add water, mix, and make happy plants. I have been gardening organic since 1969.

    1. Interesting. What amounts of each mineral are you putting in the blender for your mix? And how much of that do you add to the 10-10-10 and dilute?

      I actually got here because I was researching how to fertilize potted succulents/cacti in a mostly (2/3) inorganic soil. Not sure what’s needed in this case.

  20. Thomas DeHaven Taber says:

    Hello. Is lake ,sea weed as good as sea,seaweed?

    1. No, it’s not nearly as nutrient-rich. Still may have benefits, though.

  21. One of the things I like to do with chemical fertilizers is to throw huge amounts of it onto wood chip piles I get for free from a tree removal service. It makes the chips rot into black dirt very fast and the organic matter soaks up the primary nutrients very well. You don’t have to worry about burning chips after all. Another thing is to fertilize weeds and cut them down and let them rot, making even more organic matter.

    1. Both good ideas.

  22. Joan hilton says:

    I have purchased 10 10 10 for my perennials
    Can I just take a handful for each perennial and just scratch it in the soil?
    I’ve done this in part of my garden already, and not sure if I should continue.

    1. It depends on the size of the plants. A handful is probably too much, but a Tbsp or tsp sounds like it probably won’t hurt anything.

  23. Why are EOF of 5-5-5 better than 10-10-10 synthetic fertilizer?

    1. EOF?

  24. We used to put a cup of liquid 3-10-10 in before planting a tomato plant. (My husband worked at a fertilizer plant and it was mixed as a lawn and garden and we had wonderful tomato plants that produced quite well. They no longer mix 3-10-10 and he has since retired.) I fear that granular 10-10-10, which is all I’m finding for gardens would burn the plants. Is there any way to take a granular 10-10-10 and turn it into a liquid 3-10-10?

    1. Interesting question, thanks. 10-10-10 and 3-10-10 are both quite arbitrary formulations, and the idea that plants only need those 3 nutrients is old school, too. What I do during planting is use more broad-spectrum liquid fertilizers. Fish Fertilizer is 2-4-1 NPK but also has dozens of other important nutrients. And Sea Minerals has even lower NPK but has even more additional nutrients – over 90 – making it my favorite broad-spectrum fertilizer. And then there’s the whole biology side of the equation, which is just as important. I like to combine either the fish or the sea minerals with Bio Ag because the microorganisms are so beneficial for plant nutrition.

  25. paul g middendorf says:

    I live in St.louis.Do you have a store where I can pick up locally?

    1. Alas, that’s just where my products are shipped from. I don’t have a storefront there.

  26. crazysquirrel says:

    I would like to add something about the potash use.

    If you took wood ashes and poured in distilled white vinegar (I think it is 1 cup per gal of water), stir and keep adding until it stops fizzing, you made potash and organic acetates, both of which plants can use quickly.
    You get a tiny amount of minerals.

    About wood ashes – the highest mineral content is in the bark, not the heartwood.

    Additionally, diluting human urine 10:1 urine to water will supply nitrogen and some other goodies.

    For a permanent garden spot, till in 8% to 10% biochar down to the root zone.
    If you buy ready made (pre inoculated) there is no lag time to see benefits.
    Beware of those selling it with large chunks. Large chinks give less benefits.
    You want pea sized pieces or smaller.

    If you make your own, it can take 1-3 YEARS to see benefits.

    Purpose was to make Amazonian Black Earth, the most fertile soil on the planet.

    And it is a permanent amendment.

    Not all plants like biochar. Do your research first.

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