Question 1: I have 2 baby plants, 1 has a very thick stem and is about 5 days old, the other one is like 2 1/2 weeks old and its stem is skinnier than the new one. I have reason to believe they are the same strain but not sure. Is there usually a reason for a younger plant to be way thicker than an older plant? Question 2: I heard about some plants being 11 to 20 feet tall. How common is this? I really really dont want to top my plant, but if they are going to be taller than my ceiling, I guess I must. Input?
each strain has different phenotypes, so to answer your 1st question, maybe. as for your 2nd question, very uncommon for indoor plants to grow that tall. my first grow was bagseed that flowered for 70 days and got 6 ft tall. I had vegged for 8 full weeks and it was 3.5 foot tall when I flipped the lights to 12/12. I have some northern lights (indica mostly) that never get really tall. many options for keeping things short; scrog, lst, etc. make sure to top it, it will give you 2 main colas unread of one
any pics of the 2? that tall is highly uncommon indoors. 20 feet is uncommon anywhere as far as i know. if you can prove me wrong please show off a little. to an extent, you control how tall your plants get. check out all the stickies and if you are new to growing i strongly suggest picking up a book or two. i couldn't have done it without jorge. i don't top mine, but others feel its imparitive. its all about preference and grow space. good luck.
Not very common. You control how high for the most part that they will be. When you move from veg to flowering stage MJ will double triple in height. That being said if you place it in flowering when your plant is say 1 foot tall you should have a 2-3 foot plant. Just do the math to figure it out.