I have far too many flowers on my island. It's a problem. I got really into hybrid breeding but then they just sort of took over.
Windflowers
Probably the most significant of the flowers on my island currently, since they're what I started with.
Blue: Surrounding the Able Sisters' shop.
Orange: Surrounding the Town Hall plaza.
Pink: Placed at the entrance of the island where you get out of the airport.
Purple: No current use, spawned from the Blues.
Red: Surrounding the home of Ursala, one of my two starting villagers. Just sort of happened in the early days, since Windflowers were one of my initial flowers. I plan to move Ursala out and replace her with Diva as my Sisterly resident, so I'll probably get rid of them at that point.
As far as the others are concerned?
Cosmos
Not really a fan of these, but I have some of them on the island.
Black: I only have one of them so far, but hope to acquire more. No real plans for them as of yet, but I can find a use for them.
Red: In a diamond pattern with White and Yellow to breed Pink and Orange hybrid Cosmos.
Orange: In a pattern to try to breed more Black Cosmos.
Pink: Have a few, no real plans for them.
White: In a diamond pattern with Red and Yellow to breed Pink and Orange hybrid Cosmos.
Yellow: In a diamond pattern with Red and White to breed Pink and Orange hybrid Cosmos.
Hyacinths
One of my favorites. Plan to place them around some resident houses, both player characters and animal villagers.
Blue: Currently surrounding starting villager Snake's house. Plan to replace Snake with Sprocket, but will find some use for them.
Orange: Aiming to surround the museum with these, but don't currently have enough of them to do so fully.
Pink: Currently in an undeveloped corner of the island to grow more. Might place these around Pekoe's house when I move her in.
Purple: Currently in the same undeveloped corner of the island. Plan to place around a player character house.
Red: I have a small diamond of these, with some White, to grow Pink hybrids. Probably unnecessary at this point though.
White: I have a small diamond of these, with some Red, to grow Pink hybrids. Probably unnecessary at this point though.
Lillies
I have these and like them, but no real plans for them as of this moment.
Black: I have probably like 5 of these as a result of hybrid breeding. No current plans, but would like to use them somehow.
Orange: Same situation as the Black Lillies.
Pink: Same situation as the Black and Orange Lillies.
Red: Used to breed hybrid colors. Will probably get rid of them.
White: Same as Red.
Yellow: Sam as Red and White.
Mums
I like these and want to use some of the hybrids, but no real plans.
Green: Not really fond of these, but grew some just to have them. Will probably just throw them in a corner in the future.
Pink: Might like to place around a resident house in the future, unsure.
Purple: Like Pink, I might like to place these around a resident house but no plans yet.
Red: Have a small amount of these that were used to breed Purples. Will get rid of these in the future.
White: Have a significant amount of these because sources said they'd breed Purples. Never have. Will get rid of these.
Yellow: Used for Hybrid Yellows to help with Purple breeding like the Reds. Will get rid of in the future as well.
Pansies
They get some use. They're all right, but not among my top favorites.
Blue: I have some. Think some were from Nook Miles Islands early on, others spawned from White. No plans, but like them and will keep them.
Orange: Currently surrounding the Nook's Cranny shop.
Purple: Byproduct of the Blues, just sort of spawned. Don't know what I'll do with them, but I like them and will want to keep them somewhere.
Red: Used to breed Orange, no longer needed. Will get rid of.
White: Used to breed Blue. Probably no longer needed, will get rid of.
Yellow: Same as Red.
Roses
Probably my second favorite of the flowers, and they definitely take up the most space because there's so much variety in their coloration.
Black: Currently surrounding Annalisa's house, and probably Bella's in the future. Will be useful for Gold Roses eventually too.
Blue: I have a disgusting amount of these. No current use, but I'll probably put them around a resident's house.
Orange: No current use, but wanted to have them.
Pink: No current use, but wanted to have them too.
Purple: Currently surrounding my main (currently only) player character's house.
Red: Used to be used for hybrid breeding, but no longer necessary. I grow them sometimes for the Rose Bed DIY though.
White: Used to grow hybrids, but no longer necessary.
Yellow: Same as Red and White, no longer necessary.
Tulips
I have them on the island and they're decent, but I haven't dedicated any use to them yet.
Black: Grew them just to have them. They're off in an undeveloped corner of the island currently.
Orange: Same, grew them to have them.
Pink: Same.
Purple: Same. They're currently surrounding a pond.
Red: Were used for hybrid breeding, have no interest or need of them now.
White: Same as Red.
Yellow: Same as Red and White.
My island's due for a clean-up. I just never set the time aside to do so, usually concentrating on something else.