Which Marioverse Flower is the easiest to grow?

I'd like to think it can't be that hard to start making some Speed Flowers...

I guess Boomerang Flowers? They aren't powerful enough to suggest rarity or difficulty in growing, they appear across multiple games which suggests they are common, and they don't have an elemental affinity contrary to normal flowers that suggests some kind of specialized growing method.

What about the Power Flowers from Mario 64 DS? They bloom within a few seconds after appearing, so I think they're pretty easy to grow.

The flowers that appear when you hit them with Cappy. They don't even need sunlight or water

The giant sunflower also seems pretty straightforward to plant and quick to grow.

Have you ever wondered how hard it must be to grow a fire flower? According to the The Adventures of Super Mario Bros. 3 cartoon episode "Reign Storm", Luigi mentions how "every fire flower in the kingdom has been extinguished", with the screen panning over a shot of multiple fire flowers being watered by the mushroom kingdom fire department. Now if being watered is enough to "extinguish" a fire flower, does that mean that giving fire flowers any amount of water would cause them to be completely useless as powerups, thereby "ruining" them and not allowing them to grow properly? Are they able to survive being rained on? Maybe that's why they're so commonly found in ? Blocks all over the kingdom, because it's the only environment that they can live in without being doused out by the elements. Even if they're perhaps able to handle smaller amounts of water, I imagine that growing one would still be quite difficult to do without accidentally over-watering it, kind of like trying to take care of a succulent.

Anyway to actually answer the question idk ice flower probably it can survive cold conditions I guess

The two heads of the Copy Flower provide an answer! The Copy Flower evidently reproduces through budding - and perhaps even vegetative propagation would be successful. While quite rare (and pricey!), once a interested gardener is able to obtain Copy Flower seeds and successfully sustain at least one plant, it's nearly trivial to acquire a whole flowerbed's worth.

Of course, because of the flower's reproductive method, any given flowerbed of them is highly susceptible to disease or fungal rot (unfortunately quite common in the Mushroom Kingdom). Once a pathogen is established in one flower, it will quickly spread and decimate the whole collection - which brings us back to their rarity and price!

Daisy, all you need is the Mega Mushroom.