Why you should NEVER use a 10-10-10 balanced NPK fertilizer 

Using 10 - 10-10 for years , plants grow very well and very satisfied.

I've used multiple blends, for multiple applications, over the past 40+ years. Best all round results came from 10-10-10 in both the northeast and gulf coast. Compost and manure is the way to go, but not always practical.

This fertilizer is awesome....10-10- 10 is gold!

I have used 10-10-10 in my gardening for years. Never had any problems. Also when watering I use miracle grow liquid . My plants love it and My neighbors are always impressed.

My soil is generally low in all nutrients. I use 10-10-10 as a preplant fertilzer for field corn.The potash and phosphorus isn't needed at sidedressing so I use a nitrogen only fertilizer. Other vegetables generally get diammonium phosphate and potassium sulfate preplant, with a sidedressing of nitrogen if needed. Most of garden also gets an inch or two of compost yearly. 1/4 is always planted in a cover crop.

I've used 10-10-10 fertilizer for the last 30 years never had a problem

As a gardener of many decades, I have great respect for Professor. This video, however, is not helpful to new gardeners. It is like saying one should never use salt in cooking because you are going to add too much salt and ruin everything. 10-10-10 is just a fertilizer that is clean, economic and high in P and K. It should not be the only fertilizer to use, but it is one of the best fertilizers for vegetables and flowers. I recommend 10-10-10 and its cousins (12-12-12, 19-19-19 and 21-21-21) to all my gardening friends. You can make whatever NPK you want by mixing a little 10-10-10 with 46-0-0, 0-0-60, 10-0-0 03 21-0-0. 10-10-10 is a must have for all serious gardeners. Hoard a few bags of 10-10-10 when it is on sale.

There are plenty of nutrients and minerals in every soil. The amount of soluble nutrients might be small, but if you have healthy bacteria and fungi in the soil, they will unlock those nutrients.

There is an enormous amount of misinformation and/or suppression of valid information everywhere drowning out any source of simple, proven, rational and contemplative information, that it is beyond daunting for anyone trying to make sense of it all. Thank you for holding the line while giving us hope along w great gardening advice.

I'm also a very long time (Southern hemisphere) gardener, and have tried various products during that time. Lived in three different regions, one cold, one wet and the other dry - where I am now. Each region had diffrent soil types hence different requirements. Some years were good and some not so. About 12 years ago we had a couple of devestating earthquakes which bought tons of liquifaction to the surface. It appears to have contained years and years of nutrients. For three years I had fantastic crops, without adding anything other than compost. I do home composting. Two years ago I used sheep pellet and chicken manure mix for the first time mixed in with the compost. Crops were reasonable. I put it on again for this season. Takes a while to break down but now I have huge croping. Too much for me and family, also distribute to some neighbours and the rest goes to the homeless mission.

My container grown Miracle Berry plants do very well in with 13-13-13 citrus fertiliser. The substrate is a 50:50 peatmoss and perlite mix, which is quite acidic.

Happens here in our lake, we always get algal blooms in the summertime due to too much fertilizer run off some from commercial agriculture but majority from residential people trying to get their lawns as green as possible. I use a 16-16-16 from Walmart because it is cheap and last me a few years, in small amounts in my earthboxs and a little bit in my new potato beds that I rotate other than that I just us fish fertilizer and leaf mold for my in-ground plants.

Yep, I fell for this trap when I first started gardening. After about 5-6 years my plants were having a hard time in the summer. The soil was compact and basically dead. After that I discovered Robert's books and went down one hell of a research rabbit hole to mend my ways... This is a good video. I wish someone told me this ages ago.

Thank you for shedding some light on this subject

When growing plants, there are always multiple factors that determine what the ideal fertiliser is. I garden for a hobby, so not an expert, but I can say that each gardener should familiarise themselves with all the relevant factors. You mentioned doing a soil test, which is great. The climate. The permeability of the earth, drainage, and whether the good earth is just covering a layer of clay a few feet down. I recommend to everyone to explore their soil 4 feet down. You can dig a hole with a shovel, which yields the most visibility, or use a core extraction type soil sampler. The type of plants matter. Hardy plants do better at regulating mineral intake. Delicate plants, which are often deciduous and have delicate leaves, can be more affected by a chemical imbalance. The time of the year you fertilise matters. The dosage of the fertiliser is what a scientist will say is the most important. Almost anything is not harmful at all in a small enough dose yet is also dangerous at too high a dosage. And finally, if you’re planting plants you intend to harvest, rotating crops every year or every other year helps create healthier soil, more abundant and sweeter fruit and veggies. I recommend anyone to learn what each crop does to the soil and that way you’ll achieve much better results. Permaculture largely addresses the diversity and effects of individual plant types on soil quality and agro yield.

RU-vid recommended this video to me again. It is interesting to see my own comments immediately after the release of this video almost a year ago, It is funny to see so many thumb-ups for my comment. Professor is a respected gardener, but he is clearly wrong on 10-10-10. It is one of the best fertilizers on the market. I will buy either 10-10-10, or 12-12-12, or 13-13-13, or 19-19-19, or 21-21-21, depending on the price (adjusted for NPK). All these fertilizers do is providing your plants with NPK. Nothing more, nothing less. No fertilizer, including 10-10-10, is balanced. You add or mix different fertilizers to make the nutrients balanced.

New gardener spent a small fortune on “soil” (basically clay sold as compost as it hardened). Now I started making my own compost. I can only afford own urine mixed with grass clippings fermented, works quite well. However I see I wouldn’t need the store fertilizer

"If you can't measure it, you can't improve it." The best answer is to test your soil. Even when taking an organic approach, the "wrong" compost and manure sources can leave your garden high in phosphate too, which happened to me. Started testing my soil, and my garden has never been better. I've improved what material sources I use for compost and supplement with fertilzer based on what samples tell me.

I think the reason people use 10 10 10 is because the extension office recommends it. Every class they have always tells everyone to use 10 10 10. My soil test came back last year very low in Phosphorus and fairly low in Potassium. Every thing else was good. Their recommendation was 30lbs of 10 10 10 per 1000 square feet. I just side dressed with an organic fertilizer and added compost.

Makes perfect sense to me. I use 12-12-12 for a base and add P&K as needed but the phosphate issue makes sense.

i use 21-4-7 in the fields to produce grass for the animals. So I use a little of it for the vegetables when they are in the growth stage, you only have to take a little because it grows well. later I use 4-1-6 for tomatoes and cucumbers, the vegetables that have fruit.

12 - 12 -12 Used exclusively for general fertilization purposes. It’s a way to fert without having to worry about which plant needs what and when. Keeps from having to have multiple fert types. Especially useful for annual container growing. Like a liq 20 20 20. Where you may have foliage ornamental in same container as flowering plant. True best yo give what ya need but in a pinch throw a lil 121212 and ya be ok.

Amazing how many people don’t even think before they post. Plants like all living things require different vitamins and minerals for optimal health, growth, and productivity. Just because 10-10-10 “works for you” does not mean you’re providing an optimal environment for your plants to grow and thrive. Also, just like every person is different, so are plants as well soil types and conditions.

I grow organically and get fantastic results. It's nice that my garden is a little ecosystem that supports nature and all its life forms. I've never used pesticides and I never will and I found that you simply don't need them nature finds its own balance.

I have chicken pellets who are 4-6-8 and 5-3-2. The idea is to use 4-6-8 at the beginning of the season on most of my plants and work that fertilizer in a bit(so no full no til) then if i have a deficiency I use the 5-3-2. They are both 8 and 10kg bags for pretty cheap. Got tired of buying bagged 2kg fertilizer for 10$ when the bagger stuff has 4 to 5 times for for 15-20$ i do have some blood meal who is 12-0-0 that i could use on the extreme cases like on my strawberries, they always have a nitrogen deficiency but pretty high phosphate and potassium like you demonstrated. After i applied the blood meal. My strawberries just Had the biggest bloom grow i ever had. They just keep on coming. I changed the soil from clay like to municipality compost mixed with peat and perlite. Still had nitrogen defiency early on. New leaves burned out at the crowns. At least im going to get an harvest this year My peppers started having yelloish green leaves and i applied a cup of 5-3-2. My blood potetoes had too much nitrogen. They grew extremly big but had poor tubber development. Some of them got yellow green and dropped the blossoms before they opened. One of the main reason i got the 4-6-8. I got so far 4 kg out of my 2kg seed potetoes

Thank you for an excellent explanation. I've been using manure, compost, and letting material from pruning fall to the ground and compost for quite a while I watch a few gardening channels, and one in particular really pushes Espoma products. The couple has made tons of money from advertising the products, but I keep imagining them sneaking around at night adding compost to their gardens after they yap about the wonders of Espoma.😅

I just did a soil test, and I am very low in all 3, so 10-10-10 is fine for me, and then I will add a 16-0-10 later in the spring to push more growth

This makes sense, I'm looking for 3-1-2 now.

Honestly there isn’t a one size fits all. I’m in FL which is very sandy and alkaline low nutrients. 10-10-10 is a base then supplement as needed. I get really nice bananas, pineapples, and peaches using 10-10-10. Others may have differing needs based on where they are and soil conditions. I also maintain a good mulch pile for amending soil

I usually use a 7-3-3 ratio and have had great results in all my plants especially my citrus trees.

I wonder if the brands that sell the 10-10-10 in a slow release format, take into account how the soil absorbs the various nutrients at different rates. 🤔

bro if 10-10-10 is really 10-4-8 then the ratio is almost 3-1-2 so why is this even worth mentioning . i love my 20-20-20 it works wonders

My soil and water has extremely high levels of potassium and high amounts of phosphates naturally. So I fertilize mostly with nitrogen with Ammonium sulphate(My soil is extremely alkaline).

Very true I learned this hard way. Wasted plants last year by using this combination.

I purchased fish fertilizer: 3-1-0 for my avocado, peach, mango, and lime trees. Is it wise to use it on them?

My food forest is 3 years old and the only outside stuff iv put in is Azomite, untill just now its gotted so big i bought a bag of 101010. BUT im only adding it in tiny amounts. The forest just needs a tiny kick.

Thank you Mr. P. Next time I fertilize I’ll try and find 3-1-2 fertilizer. 🌺💚🙃

Isn't replacing the missing nutrients from our soil essentially the same thing as adding the nutrients that plants need? Seems like semantics to me. For purposes of discussion, lets assume we have perfect soil, with exactly 100% of all the nutrients that our plant needs. We then grow our plant and the plant removes the nutrients it needs (somewhat unique to the particular plant). We are then left with a nutrient deficiency equivalent to the nutrients the plant removed (ignoring for the moment the additional nutrients created by our healthy living soil). So we get a soil test and it confirms the missing nutrients are equivalent to the nutrients removed by our plant, so we add fertilizer to our soil to get it back to our 100% perfect soil. Isn't that the same thing as adding fertilizer that the particular plant needs? So how is fertilizing the soil in my example any different than fertilizing the plant? Robert, I have learned more from your videos than all the rest I've seen. I had to relearn much of what I thought I learned from other videos. So much misinformation out there. Keep up the good work!

sometimes people are just trying to elevate themselves with a particular strategy. Ive been using 10 10 10 for decades. i only use it a few times per year because i dont always need the phosphorus.

I'm going to use 10-10-10 fertilizer for the first time. Our soil takes too long to heat up to 50 degrees, so I'm going to use it to hot compost enough hay to give our Sweet Potatoes a head start.

A great video explained with simple examples. I have a 5 gallon bucket of miracle Gro basic forming and a 5 gallon bucket of miracle Gro acid forming. I acquired them from an old job 24 years ago. They are both still half full. During that time I’ve used them only on my home garden and vegetables, sparingly.

Whats wrong with using a small amount amount of 10-10-10 and supplementing macro and micronutrients as needed later? I use 10-10-10 during vegetative growth and it doesnt hurt anything. Now flowering and fruiting times i supplement with specific nutrients. I think there is more than one way to skin a cat and very seldom are nutrients in the exact perfect ratio in nature anyway. I appreciate all the knowledge you are sharing 😊

It is a great starter fertilizer. When you plant a seed, it needs immediate nutrients, and it will take up what it needs. Farmers in the 50's and before used it for their crops, and their vegetables tasted wonderful. The county extension service recommended they use it.

so my takeaway from your video, the correct ratio of the 10-10-10 is actually 5-2-3 ratio, so it is close to 3-1-2

In a different video you stated that fertilization depends on the soil you are working with -- that fertilizers should be used address deficiencies and not to feed plants. So the 3-1-2 ratio, is that for container gardening when using inert potting mix? Or is the 3-1-2 ratio a general rule of thumb for in-ground gardening? Thanks for the great educational garden videos, learning a lot.

The funny thing is that I think Worm castings has 10 / 10 /10... or close.. and it increases you plant growth by anything from double to quadruple the growth, because of the fungi and the good bacteria..

Fertilizer needs by plants depends on the plant and time year. No one kind meets every situation. Rodney

OK, you've talked me into it. Although I noticed growth when I used 10-10-10, vs. no fertilizer at all. All my plants are potted. Now, if I want to strengthen roots, what do I use? And if I want my plant to flower, what do I use? This is a big problem, my plants do not flower. Thanks.

3-1-2 ratio is where the plant magic happens!

Interested to see what this video has for me. I already know 4-1-2 is the overall ratio I want for the year but part of that is applications of 10-10-10 at certain points in the year.

Thank you for explaining this concept which no one is discussing. It is good eye opener for me who is new to gardening! I stay in multi-storey apartment so Potted plants is the only option for me. I read in one of your blogs that Potting mix doesn't contain soil and we are also not trying to improve long term quality of potted soil using compost with slow release, hence, it is better to use synthetic fertilisers. Since 3-1-2 is recommended ratio, I started searching it. To my surprise, the country I live in it is extremely difficult to find that ratio. Everywhere it is just balanced fertiliser with 20-20-20, 10-10-10 etc. Could you please advise how I can make my own fertiliser mix for 3-1-2 ratio using multiple synthetic fertilisers like Urea, DAP and Potash which are readily available on Amazon? Thank you.

My dad always used 6-12-12 and always had a high producing garden

I literally use 10-10-10 on my pastures because I can get it cheap and it works great. I've even left areas undone just to see if there was a difference and there is. Your math says that 10-10-10 comes out to almost exactly what YOU are saying plants need. You claim in this video that plants want 3-1-2 and in another video you claim the 10-10-10 is actually 10-4-8 which is almost exactly the same ratio you are claiming plants what........ So.........

I Piss in my gardens works wonders!

To make matter worse, they also sell 2-2-2 & 20-20-20 to confuse people. 🤣

First of all, it really depends on the plant. Succulents and conifers need way less nitrogen than the deciduous plants. But they may start browning if they lack potassium, and they will eventually if you don't apply it. In fact, manure can literally kill these plants. The nitrogen will boost rapid green growth, but there will be not enough potassium to support its health. So the plant will exhaust itself.

Since this is talking about plants in soil, what fertilizer should one use on plants in pots with potting mix? Is there a good slow release type? Surely potted plants need some of all three NPK. Thanks.

I don’t agree at all. A balanced fertilizer is simply a supplement to what is already in the soil. Nitrogen is the most important consideration. Either use the balanced or use 6-16-16 for root vegetables.

Is it possible to use azalea fertilizer as a general fertilizer? I have 2 boxes and will never use it all, so want to use one of them for general use on plants.

A lot of wisdom right there.

I guess it might be OK to add a bit of "balanced" fertilizer if you are using legumes to fix nitrogen?

P2O5 and K2O compounds do not exist in fertilizers. Likewise, Potash does not contain K2O (potassium oxide), which plants do not take up. The amount of potassium is often reported as K2O equivalent (that is, how much it would be if in K2O form), however, to allow apples-to-apples comparison between different fertilizers using different types of potash. ~wiki

Thanks for a scientific explanation. I learned something from you today.

That is for garden soil it seems. What about fruiting or flowering plants? What about potted orchids? Don’t they need phosphate to flower?? I’m still confused 😞

I got a basil plant, small, I searched the internet and first article said use 10 10 10 fertilizer. Then I saw your video saying do not use 10-10-10. But Is this the one in the million case where 10 10 10 is appropriate? Thanks

I always had good luck with it. I use other things too.

What if you primarily use a decent compost (high nitrogen materials supplemented with wood ash for potassium) and use the 10-10-10 to add some phosphate to that compost?

my soil test recommends 12-12-12 and i cant find it locally. ok to use 13-13-13?

Since "balanced fertilizers" actually deliver 10% N, 4% P, and 8% K, their ratio of N to P of 10 to 4 is equal to 3 to 1.2, and their ratio of N to K of 10 to 8 is equal to 3 to 2.4. Wouldn't this distribution of 3 to 1.2 to 2.4 be fairly similar to the 3-1-2 distribution of nutrients that plants actually need?

I use 10-10-10 around my lilacs, Raspberries, and around my apple trees in the spring. A couple times a summer/fall I spray miracle gro around them. Perhaps I’ll find slow release organic fertilizer to replace the 10-10-10.

I'm a little confused...in another video you pointed out that the 10-10-10 is in reality a 10-4-8 because of the O molecules in the potash and phosphate. So it seems that the 10-10-10 is in reality closer to the 3-1-2 ratio in terms of the 'actual' nutrients in the mix.

Does using manures without composting, potentially transmit pathogens and harmful bacteria to the garden? And is there a soil test for home gardeners that will accurately test not only for NPK but also micronutrients? Wouldn't a foliar spray with the appropriate nutrients be just as effective as applying fertilizer to the soil? Has anyone else noticed that academic types in various horticulture pursuits, seem to always advocate for multiple applications of fertilizer without mentioning soil testing?

Makes sense what you suggest, but I have a small backyard and no room for an in-ground garden. I only use fabric grow bags or vertical planters on my large outdoor patio. I make my own potting mix and add different amendments. What would fertilizer, etc. would you suggest to amend the potting mix and continue to use during the growing season? I am in zone 8b.

At 2.22 stated plant uses nutrient at 3-1-2 ratio, does that apply to hydroponic planting too? Thank you very much for sharing your knowledge. Update: Found the answer in your other video. 3-1-2 ratio is actually applicable to hydroponics. I will try out this ratio with micronutrients added. Making the time to watch all your videos, thanks again.

Both Nitrogen and phosphate contribute to algae growth and one contributes to the other and algae needs both to bloom.

This is why I tend to keep Miracid equivalent 30-10-10 around for bad rain weeks. I have all sorts of organic tricks to get long term soil health but, when nature flushes your soil out with hard water, the blue stuff works.

I use a 10 10 10 water soluble weak solution right in the root zone no where else...seems to work

I use 20 20 20. No problem. 24 12 6 is good for grass, lettuce green leaf vegetables.

is this why people started coming up with the saying for gardening that less is more? if all you have is 10 10 10 then you better use less than needed for nitrogen or you will have more problems then using no nutes, potentially

What is the best ratio for something like citrus trees?

You lost me a bit on this one, professor. If 10-10-10 is actually 10-4-8, wouldn’t that mean the ratio is actually 2.5-1-2, which is very close to your ideal, 3-1-2. I understand that phosphate and potassium linger in the soil, but I’m not sure that means one should never use 10-10-10, does it?

Fish emulsion is a 5-1-1 and works pretty well. Given the knowledge that nitrogen moves/leaches out my containers far faster than the other two, makes sense as to why long term use of fish emulsion should be fine. As long as I don't use too much at once or too often, it seems like it makes sense at those ratios. I just worried it would be too much nitrogen for flowering stages. I used a bloom boost product from Alaska company that makes the fish emulsion I use, and that made everything bloom like CRAZY, even my oregano which I didn't intend. I learned I definitely don't need to use that stuff in general for my garden, but it certainly helped with blooms. What do you have to say about bloom booster products that are 0-10-10 or things with no nitrogen? Specifically for inducing blooming on already established plants?

what about water soluble nutrients being fed to potted plants, does K stay at the top then? Also does 3-1-2 still pertain to water soluble fed potted plants?

Thankyou!! I think I was getting the too much phosphate problem

Best garden channel

Hate to say this being an organic grower. But 10-10-10 miracle grow as a hydroponic nutrients was awesome. Now it's not available anymore. The new one didn't work.

Sir! Thank you so much for your expert knowledge. I just found your channel Feb. 14th, 2024. QUESTION: WHAT IS THE BEST FORMULA FOR A KRATKY SYSTEM For 5 gallons of water for Greens? I assume there would be an increase for vegetable like Tomato & Peppers The hydroponic formulas are Too strong and expensive. What would you recommend as a DIY mixture?

What should I use to get Karl Foerster grass to bloom, as it did when I bought it? It is planted in a very big container, not in the ground. 10-10-10 is recommended online!!!???

I have start off with 17-17-17 and add N-P to meet the soil test recommendations. Most of thee lawns here are in the range of 25-20-15. I do however get custom mixes for pastures. Maybe you can tell me, most every lawn fertilizer I see for sale is 25>2-2. However, none of the soil tests I get back are anywhere near that. Why so much N?

If I missed it please forgive me. 3-1-2 is the optimal balance but what is the optimal balance in trade number descriptions please. EG 30-10-20 is not actually that hight in P and K. thanks

Thank you for your video. with regards to NPK ratio: if I want flower to bloom or bloom more, I don't need high N, but I need high P, correct?. High N is for plant early growth?

"Who would want an UNBALANCED fertilizer?" I had to chuckle

What about bloom boosters, and gardening advice that says too much nitrogen makes leaves grow at the expense of flowers? One example is roses, another is morning glories, even nasturtiums.. last year, my nasturtium leaves were huge, with barely any flowers.

But what about foliage vs flowers? I thought different fertilizera trigger different phases of growth?

What about a 12-12-12 for when over seeding a lawn?

Got a soil sample test done and it shows too much phosphorus and slightly below the ideal amount of potassium. They recommended 15-0-15. I was using a 24-8-16 during the seedling and vegetative state and switched to a 18-18-21 for budding, flowering, and ripening. I stopped doing this last year after watching one of your videos where you mentioned this. Test also showed too much calcium. I read online that increasing aeration and drainage can help with lowering calcium. Soil is compacted so I’m going to double dig anyway. Old wood borders in the beds are rotting away and need to redo them. Soil is fine to about 6” then hits compacted soil. Do you know if double digging lowers calcium?

3-1-2? Damn, why are so many fertilizers with a higher middle number? sometimes twice as high as N or K.

I get so confused about the scientific basis of gardening recommendations. For instance, this whole topic assumes the plant needs for N,P, and K stay constant over the life of the plant. Recent science suggests otherwise, right? K+ is only required later in the life cycle of a plant and is detrimental early; nitrate is a suppressant to growth early in the cycle. I'll stick with compost and let the soil biome figure it out. I think.....

You say 3-1-2 is balanced but doesn't it make a difference if you are in vegetative stage or flowering stage?

can i use fermented stinging nettles fertiliser in hydroponics instead of other nutrients solution?