female

how much time i have to wait to know if my plant is a female?

they are 2 weeks old.

You will have to take cuttings (unless it is an auto flower strain) and put them into flower to show sex. They can be flowered when mature (when you have alternating nodes).

how can i do that? take cuttings?

It is cloning. An easy way to know you have all females all the time once you have a good female mother plant to take cuttings from. Do a search for cloning marijuana and you will get the idea. Plenty of good videos online showing how to do it also.

Dude hes asking about how he can tell when his plant will show signs of sex, not cloning. Your making this a whole different discussion. Might aswell told him to buy fem seeds.

If you are growing indoors when you change the lights to 12/12 it will show sex within 2 weeks. and outdoors as the days get shorter the plant will show sex also. Its late in season for outdoor though kind of.

It shows sex by 2 white hairs coming out where the branches meet the stem.

I have always determined sex by flowering a clone from the mother plant. He was asking how to sex his plants. I offered a method that I use. It is hard to explain how to sex from preflowers which is hard enough for an experienced grower. Too many gray areas for a new grower. Keeping it simple. I have never been in such a hurry that I haven't been able to use my method with 100% reliability.

You do not need to take clones - just read my link below.