I planted a seed about three weeks ago.

I didn't germinate it, just dug a small hole and dropped the seed in.

Behold, the seed hath sprouted. The plant's really small, about the size my indoor plants were after about 2-3 days post-sprout.

Is there any hope for the plant if I just let it be on its own?

I really have no expectations for it, just an experiment pretty much. It's outside by the way.

weed is naturally outdoor plant it will survive..