I need to fertilize my sales iris heavily, as we're on sand. I use a 10-10-10 and Miracle Gro often. My flower gardens get compost and fertilizer every couple of years. My veggie garden, I never fertilize. I use compost and mulch heavily with straw. Had no diseases at all on the tomatoes this year, with the straw, even though we had such wet and dry periods. Raspberries and asparagus get some 10-10-10, just too big an area for the amount of compost we produce.

I never fertilize my veggie plants except with compost and occasionally decomposed horse/steer manure, especially when it is a new area opened to planting.
I never fertilize the perennial beds or raised hardy succulent beds. I do add compost to the perennial beds about once every two years, and grit/gravel as top dressing for the succulent beds.

I put Osmocote in the hole when I plant things. And the daylilys get Osmocote a few times a year. Other than that it's just up to the decomposing mulch & my many, many, many earthworms. Once in a while if something looks peaked I will give it a shot of liquid Miracle Grow.

I don't grow veggies but if I did, I'd opt for as organic as possible (I'd have to do them in containers where I live so that would be doable) but my flowers get amended soil each fall/early spring depending on what and when I'm digging, dividing, moving/removing and planting. I don't go out of my way to buy stuff. I use standard miracle grow, still have some Messenger which I barely ever used--wonder if that stuffs any good now, Super Thrive occasionally and with new plants. I put new aged compost (have to buy it, no place at my apt to compost), mushroom compost, a little peat, greensand as I tend to have some heavy clay areas and I dump a small bag each of perlite and vermiculite into the flower bed. Figure it can't hurt. I also do the scoop of Osmocote in planting holes and depending on the plants water needs I put a little bit of pre soaked water crystals in there too. Always in the bottom of the hole so the roots have to reach for any water stored that they may need.

I've been gardening in the same bed for about 16 yrs now and have tons of earthworms which weren't there in the beginning and even in my containers which I hope tells me I've done something right

Well, now that I've answered I take back that I don't buy alot of stuff, looks like I do:LOL: But I'm truly not great about using chemicals and bagged fertilizers. Nothing is sold in containers small enough for my little patch plus I don't like the idea of storing anything leftover like that in the house w/ the pets so I've adapted to using more basic amendments that can just be dumped on and dug in. One large container of granulated miracle grow with 3 plastic sleeves in it can last me a year or more depending on how much I have to water (yup, all by hand with watering can filled up from my kitchen sink--no outdoor faucet for use at my complex:lol)

When ya need it, ya need it.
If ya don't need it, ya don't need it.

(But all soil always needs more compost.)

Insufficiently-amended clay, or sand with little organic content and little mineral content: these need fertilizer.

(It also needs the organic matter in compost, but you can haul and add a few pounds of NPK easier and faster than cubic yards of compost.)

If you have enough raw materials and space and energy to make plenty of compost for all your beds: you probably won't need extra fertilizer after a few years of amending the soil.

In my case, my compost heap at it's largest was tiny, and I have to haul bags from Home Depot in my trunk, because the CG bulk compost I've seen is mostly sawdust: expensive sawdust!

I tend to expand my beds faster than I can acquire compost. So, for me, fertilizer is a stop-gap. I'll need it until I find sources of cheap, good compost and mulch that haul themselves into my backyard and spread themsleves around.

More likely, I'll eventually run out of space to make more raised beds where there's any sun. Then, one bag of compost at a time, I'll bring all my clay up to being pretty fair soil.

And hopefully I'll be able to haul enough compost each year to keep the soil healthy and fertile despite the organic matter decomposing every year.

In the absence of abundant compost, it makes the difference between slow, stunted, short, scrawny, struggling, pathetic seedlings succumbing to slugs, vs. vigorous healthy plants.

I don't understand where worms come from, can any enlighten me. I mean how do they get there to begin with? In my straw piles, underneath I found tons of worms. Love it!

I try to vary soil ammendments and fertilizers.
Sheep manure, peat moss and sometimes cow manure.
Container plants get some soluble fertilizer and some manure tea.
If I am not watering with tap water, I use Epsom salts sometimes.
I do compost , but it does not generate enough for all the garden beds.