how long does it take for a cow plant to grow?

No idea :p Probably about 3 or so days. :) Feed them every 12 hours or they'll either die or kill you sims XD

Like 2-3 days.

Carl's guide says 24 hours. But I remember it taking longer. It was a fairly fast growing plant, but I thought around 2 days.

Iv'e had a cow plant grow within one sim day. Iv'e had others grow longer. So, it really depends I guess. I'm watering them when they need watered, weeding exc. So, I think it't different everytime.

I'm sure it's 3 days. :#

About the same as a normal plant to go from sprout to fully grown. Cowplants don't need weeding or anything, but make sure you feed it every 12 hrs and also play with it and pet it. I haven't had a cowplant die yet. The families that have them....it almost seems like a pet to them and I would be sad if they lost it. So I make sure they take good care of it.

mine been growing for 5 days

Thank you for the post @maxisacactus !

However, this thread is 2 years old, so I will be closing it :)

Thanks,
-Mage