I found some seeds in my mid-grade a few weeks ago. I planted one in my mom's garden and to my surprize it started growing. It's pretty hot out. But it gets watered ever night by sprinklers. I think it's probably gonna die cuz the weather and stuff.
It may very well grow as its mid summer but at the risk of sounding boring i don't think growing in somebodies elses garden without there knowledge is very cool. If its seen your mum will take the heat.
well if "by your surprise" it does end up growin and you wanna keep it.. i would move it.. cuz when it gets bigger the smell will be unmistakable.. and your mom will probably know what it is and then the shit will hit the fan