Sure, you can flower plants that you've raised from seed. However, don't be put off by cloning. Piece of cake- and will both save you weeks and weeks later on and give you assured female plants.

However you go, you will first raise up some seedlings under 18+hr/day light to sexual maturity (preflowers showing at nodes, 4-6 wks).

Now, you can either flower the plants you grow from seed and hope for females (statistically, 50% will be male; feminised seeds go about 60-80% female), or you can take a cutting or two from the seed grown plants and flower those cuttings under 12/12 light to determine sex. Of course, the clone/s will be the sex of the mother.

Once you've determined the plant grown from seed is female, you can then flower the clone/s you made, or you can raise them up as mothers. A mother plant is simply a known female plant from which you take cuttings. You can also either flower the now known to be female plant you grew from seed or you can use it as a mother plant.

If you get ordinary seeds, half will be male. Feminised seeds run about 60-80% female. If you only raise plants from seed, you'll wait 4-6 weeks in EACH CROP for plants to come to sexual maturity.

However, if you establish a mother plant and take cuttings, you'll KNOW each plant is female. It only takes 7-10 DAYS to get a cutting to set root- sure beats waiting 4-6 weeks for a plant which may OR MAY NOT be female!

Yes, establishing a mother and taking cuttings is a little bit more work- but in the 4-6 weeks you wait for seedlings to become sexually mature, you could have a crop 3/4 of the way (usual flowering is 8 weeks) to being harvestable buds.

Depends on whether you like smoking dope or watching grass grow.

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How not to grow dope - 'Not Your Father's Marijuana' / 'new super cannabis' / 'extra potent hydro' myths busted
DIY batwing reflector - DIY power panel to keep electrics safe and neat - DIY low-temp 3-day bud dryer - Get a harvest every 2 weeks - Photoessay: A batch of clones in rockwool - Project Big Blue Bastard: DIY 5-tube, 100 watt UV ioniser

...and don't even THINK about asking me how to hide your grow from your MOM. This is an adult sport. Give it up until you grow up.