What is the spawn rate of the Jacob's ladder(lily of valley)?

[Airysuit]

Hi all!

So i got a 5 star rating, but had to mess up my town quiet a bit to get there! I just really want the Jacob's ladder, but now I'm wondering for how long I have to keep my town like this? For example if i want 5 plants, would that take me a month or so? Or less?

Thanks!