This site lists the NPK ratios for every stage of growth for tomatoes:
https://gardeningwithallie.com/npk-for-tomatoes/
I never get that technical, but I always add crushed egg shells and about a 1/2 cup of bone meal to each planting hole (same for my peppers, zukes and cukes) which gets them off to a good start and helps prevent Blossom End Rot.
Higher potassium helps when they are wanting to flower and set fruit.
I don’t remember if you have room to compost, but Compost Tea is cheap (like almost FREE) and good for Every Growing Thing. :)
Seriously? You don’t have to over-think it. I just fill a 5-gallon bucket half way with compost, add water, put it in a shady spot, stir it when I remember too, and dipper it out for my plants, applying it at the base of the plant.
Full instructions here, for those so inclined:
https://www.treehugger.com/how-to-make-compost-tea-5207373
Thanks. I do have a compost bin.
I think I will use up my left over 99mg 100 or so Potassium capsules later on. Bone Meal is rather high. Maybe Jobe's 06328 Bone Meal Fertilizer Spikes, 50, natural (2-14-0) $7.74 ($0.15 / Count) would be justified.
I do have many lbs left of Hyponex 40 lb. All-Purpose Fertilizer 10-10-10 (from when it was about $10) some of which I spread out every year, but it comes as hard bits, slow to break down.I wonder how long it would break down in water.
Should get soil tested, but I do not want to spend much money on this garden. A few years ago a few bags of this were mixed in: https://www.homedepot.com/p/Black-Kow-1-cu-ft-Manure-50150151/308819334
This is attractive but I will pass on it:
2-5-3) 4 pound bag $6.97 https://www.amazon.com/Jobes-Organics-9026-Fertilizer/dp/B002YOJDAS/ref=sr_1_24?crid=FUMCHDL70HRF&keywords=bone+meal&qid=1685348553&sprefix=bone+meal+%2Caps%2C150&sr=8-24