I’m not organic when it comes to ferts and I test my soil so I rationalize that by not spending a lot of money on general purpose fertilizers. So my answer would be to stick to real-chemical-name fertilizer and to look around for free resources where convenient,

i get a big bag of urea which I mostly use to make compost with wood chips. very roughly $26 per year for a half ton + of compost. That also effectively takes care of P and K.

A similar size bag of calcium nitrate for $50, which looks like it will last maybe 3 years. Useful for early season cool weather used directly on orchard trees. So $17 a year.

Zinc sulfate maybe $5 a year. Iron sulfate $8

Very small additions micros. I got like a lifetime supply of copper sulfate for $20. A bottle of Boric acid roach killer for Boron. Maybe $2 a year .

lately I’ve been experimenting with monopotassium phosphate. I agree with those that say it stimulates flowering at least in a N deprived setting. $6 per year. Not strictly necessary.

The big expense I’d say is for chelated iron. I read somewhere that Apricot trees don’t like Sulfur so I use it there $72 for five pounds, but it’s probably enough for seven years at least for my two trees so not so bad. Also probably not absolutely necessary.

I have General Hydro Maxibloom hydroponic ferts for the Aerogarden. Pretty inconsequential. Maybe $4 per year.

Grand total: $65 per year. And I’m not particularly economical. If I had access to chicken manure I could skip the Urea and Boron and maybe one or two other micronutrients.

How big of a garden are we talking? I have about 8x15' plus a 4x8 raised bed. The in ground I only used root enhancer at planting (Luther Burbank soil) and the raised bed I've used about 1/4 of a $10 bag of organic vege fertilizer. I'll be getting back to composting after a move, so don't anticipate needing more starting next year.

I've started to use Texas Tomato Food and Texas Vegetable formula for most of my garden in the last couple years. I also use Urea for all of the nitrogen lovers like alliums, brassicas, and greens and use triple 13 for my Asparagus beds. I paid $30 total for a 50 lb. bag of Urea and a 50 lb. bag of 13-13-13 this spring at my local agriculture co-op. Pretty cheap!

I ordered 4 gallons of the Urban farms TTF and TVF (2 of each) this spring that cost $136 including shipping. This seems like a lot of money but each gallon will make 256 gallons of fertilizer at the recommended 1 Tbls. per gallon dilution rate. I love these products! The 4 gallons will probably last me 3 years.

I am growing vegetables in ground and in plastic containers. So far this year I mainly have used Miracle gro all purpose fertilizer which is way too high in nitrogen and low in other stuff. I try when I can to buy the one for tomatoes but thats also expensive(ish).

My easiest source to buy is from big box stores, which I think are not the best options. Most people here don't garden and for the few that do they can easily over priced and sell fertilizer to. Spending $75 is a lot even if its an investment for years. You most likely have a much larger growing area than i do. With the 1.5lb miracle gro I go through 1-2 boxes of it a year. I just think its expensive for the amount I get.

i am going to look into Potassium chloride. What is the general prices so I know what I am looking for? What about for Phosphorus?

I am unsure of the area of the total beds. Its not large. Here is what I have growing:

In ground:

• 16 tomatoes
• 9 cucumbers
• 3 butternut squash
• 4 sweet dumpling squash
• 1 eggplant
• 1 Blueberry
• 1 peach tree
• 2 grape vines

In containers:

• 5 thai chili peppers
• 3 trinidad perfume peppers
• 7 eggplants
• 1 habanero
• 1 cayenne pepper
• 2 chili peppers
• 3 tomatoes
• 6 string beans

When you decide what you need, check to see if there is an organic farming group in your area that does bulk orders. Here in NH you do not have to be a member to participate. You get the order list early in the year, send in your order and choose a pickup site. There is only one chance to order and pick up. I usually get a one gallon of liquid fish/kelp fertilizer every years, seed starting soil and whatever fertilizers I want that particular year such as kelp meal and a general vegetable fertilizer. This year they also had Coast of Maine products at less than the usual retail price.

This time of year, some chains are discounting their garden department. Ocean State Job Lots has some bagged fertilizer. I got bone meal one year.

Home Depot (and I imagine other stores) have store brand products similar to MiracleGro. I've used Vigoro from Home Depot. They have a 5 pound All purpose plant food concentrate for $6.98. A 3.5 pound bag formulated especially for tomatoes, peppers, and veggies with added calcium is $4.98. I'm quite sure they both include trace elements, too, just like MiracleGro. The Vigoro is less concentrated so figure that in when comparing pricees.

https://www.homedepot.com/p/Vigoro-5-lb-All-Purpose-Plant-Food-611612/203132283

Since I am focusing on the organic method of gardening, I get a lot of mileage out of three free ingredients:

Shredded fall leaves

Used Starbucks coffee grounds

Horse and cow manure

All of those ingredients, however, are useless in their original form, and must be composted to be of value - preferably all three together. So, it takes time. In six months they have decomposed to the point where you can spread the mix on top of the soil as a mulch, and then let if finish composting down into the soil. If you leave them a year, they are sufficiently degraded to the point where you can dig the mixture into the soil if you want.

Of those three, the most valuable (as well as the most abundant and readily available, unless you are in a desert climate) are fall leaves. Not only are they a great source of nitrogen and carbon, but they also contain trace elements that the tree roots have brought up from deep in the soil. Decomposing leaves are the primary component of the forest floor and the way nature replenishes the soil. Leaf mold (leaves that have been left in a pile to decompose for two years) have been the primary amendment for French gardens for hundreds of years.

My neighbors think that fall leaves are a nuisance - an autumn mess to get rid of. I see gardening gold and am happy to take them off their hands.

Leaves are definitely the best in my experience. I suspect as you do that has to do with the availability of micro nutrients because of their deeper roots.

Horse and cow manure is variable. Coffee grounds are overrated. I wouldn’t turn them down but mostly they are the right shape and size and they look great.

This has been discussed here many times here, but compost really isn't fertilizer, though it can be considered a nutrient. The NPK of compost is extremely low, compared with any real fertilizer. It's like 1-1-1. No problem, you say, I use a LOT OF IT! But that NPK pertains to fully-broken-down compost. That is, it's the NPK that comes out of compost when the organics are thoroughly broken down in the soil. That may take many months. So compost is a fertilizer like eating food that isn't nutritious unless it stays inside you for many months. Not a good food. Real fertilizer is a right-now nutrient.

Now, it should be said that incompletely composted manure can still have a lot of urea in it, which makes right-now soil nitrogen. But be careful. Incompletely composted manure releases it's nitrogen as ammonia, and that ammonia can kill plants, if there is a lot of it. Also, P and K may come out of compost somewhat more readily than N, and so do beneficial microbes.

That being said, I use leaf compost almost exclusively. I love the stuff. But the purpose of it is for soil structure improvement, and not so much soil fertilization. Though when I dig in loads of compost in the fall, by springtime there is some fertilization value in it. I can't just dump compost on something and call it fertilized.

There is "right-now" fertilizer, and "eventually" fertilizer. Think about what you really need.