First Outdoor Grow

Hello peoples. I just recently started growing my very first plant. The plant is almost in its seventh week of growing from when it was just a sprout. The plant looks good and healthy, but I am having a few issues which I need help correcting. Currently I am feeding the plant a 20-20-20 Miracle-Gro nute solution with some silicon additive to improve the plants cell structure. I water every three days and I am growing outdoors in Texas. My plant is very healthy, but many of the older leaves' edges are burning and I'm thinking that the plant is sitting too high to the sun. Also, I just topped the plant and was wondering if the plant will continue to grow up once it has finished recovering from the topping. I have posted some pics below.

Bump! Bump!

Looks great. Cold temps probably stunted it a bit as it should be bigger for 7 weeks. The main stalk will not grow anymore but all the other shoots will continue to grow upwards. It looks like your goign to have two dominant colas that will stretch more then the others.

Has the plant been outside from the beginning? If so, I doubt the sun's burning it.
It's looks like it could be nute burn though; 20-20-20 seems a little strong.

thanks for the input los muertos and dank. i could understand it possibly being nute burn, but i barely use any nutes and i have only used the 20-20-20 solution the past two times i watered which was two times within 6 days.

and yes the plant has been outside since the beginning