hello people im just writing on here because ive grown 3 plants there 3 weeks old and in a greenhouse - 2 of them are growing at a good rate for this time of the year but 1 of them is growing out of control its dwarfing the other 2 by 5 inches :S i havent fed them with nothing yet so im confused - could this be a sign of male plant ?

could just be a different pheno. Ya wont know until it shows preflowers if its male or not.

wots a different pheno im new to this

pheno-phenotype its the same strain of plant it just has some different traits eg:one plant may grow fast and bushy and finish quickly while others grow fewer/thinner leaves and finish slowly
hope this helps mate
ollie

Just cut it down to the hight you want it, itll bush out nicely. It could well be a male, they tend to be bigger and stronger, or it might be a stretchy pheno. They will show their rude bits in a few weeks probably anyway