I use organic compost for my vegetable garden. For my roses, I use Miracle Gro for Roses granules which I mix in a watering can. In the rest of the garden I use blood meal around lilies to repel rabbits, bone meal for bulbs and rhizomes, and occasionally general purpose Miracle Gro but mostly I'm too lazy.

I use compost around most things if I have enough, and fish emulsion once a week or two or whenever I think of it on my flower beds and my flower pots. I use a watering can. I give used coffee grounds and banana peels to my roses. My raised flower bed has Pro-Mix ( with those stupid water saving gel things)in the top foot or so. I also throw any excess used coffee grounds on the lawn before it rains. Last year I used chopped leaves on the lawn in the fall and in the spring I used corn gluten. I don't know if my fish emulsion will work for my new tulips. Something I'll have to look into.

Other than that, I'm either too lazy or there's too many mosquitoes out to bother, and the more I read the more I don't trust what's in most of the stuff that's on the market. Too many chemicals and too many gimmicks.

I use compost in the veggie patch and flower beds, fish emulsion on the potted flowers and tomatoes. I lifted some of my tulips last fall and gave them a good dose of bone meal, I will definitely do that again this fall for the rest. C

Sea soil for organic matter.

I used 30-0-5 (granular grass fertilizer) this year in the shrub and perennial beds. Reason being that apparently phosphorus is usually very high in soil, with one application lasting for 10 years. And most soils are actually quite low in nitrogen.

Nitrogen promotes leafy growth, phosphorus promotes root/bulb and flower development, and potassium is for all around plant health, stem strength, that kind of thing. So lawns I feed high-N fertilizer, something like 16-0-0, but usually only once in the spring instead of the 3 times a year the chemical companies want you to do it. I grow things pretty intensively, so for most of the veggie garden I fertilize heavily once or twice a season with a balanced fertilizer like 10-10-10. For things where I want lots of flowers or strong bulbs, like fruits or onions or spring bulbs, I hit in June or thereabouts pretty heavily with a high phosphorus fertilizer like 8-16-8. Things like apple and plum trees and saskatoons I don't fertilize.

I produce about a half-cubic yard to a full yard of compost each season, and I spread that around the veggie garden in the fall. I rake many of the leaves that fall in the autumn onto the flower or rose beds to provide mulch, and leave some of them on the next spring to rot in place as compost.

Many plants, if you feed them nothing but nitrogen, will produce a lot of weak stems and leaves, and produce few flowers. It would be particularly bad for most bulbs and rhizomes. This is why there are different formulations for the needs of different plants.

It's best to minimize phosphorous in lawns because lawns don't use much, and it's the place most likely to end up in run-off and get into waterways. All the trouble with Lake Winnipeg is from phosphates from various sources. (farms, fertilizer, human sewage, household cleaning products) Everybody on this forum except those from northern BC and northwest Ontario are on the Lake Winnipeg watershed, we're all responsible. But I question whether using an 18-24-16 fertilizer on a few rose bushes, even if everyone did it, would make any difference at all.

If you have good soil, then you probably have enough P for the next few years. Seriously. P is immobile as well, so once it's in your soil then it ain't going anywhere.

If you're using 10-10-10, and I am using 16-0-5, then you just need to use 1.6 times as much fertilizer as me to apply the same amount of nitrogen. Or I can use 62.5% of your usage. I'm stingy.

Fertilizers are overapplied. Especially P, what with most of us having heavy clay soil. Manufacturer suggested applications are too high.

And, of course, adding too much P or K also have their downsides.

The WSU has an excellent blog mostly run by Linda Chalker-Scott that has extremely useful information on fertilizing and other plant matters.

https://sharepoint.cahnrs.wsu.edu/searchcenter/Pages/results.aspx?k=fertilizer&cs=This%20Site&u=https://sharepoint.cahnrs.wsu.edu/blogs/urbanhort/
(Click Cancel twice when you see the username/password prompt)

More gardening myths debunked:
http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/index.html

Here is a link that might be useful: Fertilizing