I have seen 1 lb Sativa's grown in 100 L bags, but these were in the tropics & was only 7' tall. I myself have grown a 1 lb. plant{bagseed indica} in a 16" pot :greenthumb: When ya dig yer holes, throw in LOTS of shit.....horse shit,[ I imagine there's lots of this in Texas], cowshit, chicken shit & lots of GOOD compost. I don't think they need to be 5' across, maybe 3' X 3' would be better for your back....good luck m8 :greenthumb: