Growing weed in low light conditions

Ok, so I looked around some plots of land and it turns out alot of work is being done and our once 2 acre plot by our house full of nettle, rag weed, wild sunflowers and beautiful spots for weed plants is being tilled and the trees are being cut down! I have no idea for what yet but I planted my seedling (weed of course) by a fence line in the woods, the soil is nicely moist but theres like hardly any sun there are no full sun plants like ragweeds and stuff where I planted it just some low shrub-like trees and big tall ones so my weed plant gets scarce, scattered light. I dont think this will work out it seem like it would cause the plant to be long and stalky reaching up for light can I top it safly in these conditions or pin it to the ground or what?