Guys i hope You realize that You can speed up growing process. Just in case i will post it.
U need to have this fertilizers upgrades unlocked/bought. There are 2. Basically when You have the first upgrade u can use fertilizer on weed that has around 80%, 75 mayby. And it finishes it. Cuts the rest of time. 2nd upgrade gives You option fertilizing, finishing growth at 50% of completion so u save half of the required time.
Thanks to that, its not so long.