However all marijuana growing areas must be enclosed locked and they cant be viewed from the outside in other words it is tricky to grow cannabis outside and meet all state laws incidentally colorado residential properties are allowed to grow a maximum of 12 plants while medicinal marijuana growers are permitted up to 24. Trainwreck has been around for a minute now and it is one of the best and easiest strains for growing outside it easily grows well over 2 meters and has a very potent yield one plant can yield as much as 700 grams when grown outdoors it takes only about 8 or 9 weeks to flower and you can also train and top it to further increase its yield. Harden off your marijuana plants if you start your plants inside in a grow room or on a windowsill harden them off before transplanting them to an outdoor location hardening off is a process in which plants gradually become acclimated to the outside environment over a period of seven to ten days. Choosing the soil wisely youll be hard pressed to find a grower who uses their native soil most times youll need to adapt your yards current soil to create the right mixture for your cannabis ideally your soil should be between a ph of 60 and 70 and contain an adequate amount of micro and macronutrients