In order to make marijuana into a very healthy looking bush...i mean a bush not bushy...the grow bible says to wait til plants are in 6th wk of growth and trim no more than 1/2 of the plant (i know it sounds painful but i've done this)...wait another 3-4 weeks and trim 1/3 of the plant again...one more month and then trim 1/3 again...wheat i mean by trim is not to top carefully but to clip the plant around on all its sides, leaves, shoots everything but just take a lil bit off everywhere and never do more than 1/2 of the total plant matter the 1st time and 1/3 thereafter...i've done it and wish i had pics...last year i had a bush that was 6 foot in diameter and 4.5 ft. tall...ppl literally would stand next to this plant b-4 it bloomed and never recognized it as a pot plant...one dude said and i quote"that plant has leaves that look just like a reefer plant but that sure ain't no pot plant...don't have a scale but it was the best bud of my small summer crop