yes. u can plant several clones into 1 container. i have a friend who routinely plants 2 clones per 3 gallon. his yields are good, but he grows columnar varieties that dont stretch or branch out…
ive ran in short beds (3x3 w/ 5 plants and with 9 plants, and 4x4 with 5, 9 and with 16 plants) and in large plastic totes 22gal+, with 6 oir 8 plants, depending on length. (one with holes punched, set inside another with a solid bottom)… its no different in principal than what yur suggesting.
yes u can grow multiple pants in one container. but should you? u could get something decent off of 2 clones in a single 5gal., but like u said u would have to force early, and yeild would suffer. remeber a plant will double or triple in size, by the time its harvested. so u have to force when the two clones are 1/3rd the way from crowding each other. if u want to veg longer, i wouldnt top, but instead bend and tie down both plants’ tops. like away from each other and encourage lateral growth… it still be a matter of timing… you;d have to anticipate the added flowering growth when deciding when to force.
IMO, instead of a single 5gal with 2 plants, I would grow two plants each in their own 2gallon container. or grow 4 plants in 1gallon containers. veg 2-3wks in 24/0 and flip them. if u have tall strains, i would top at the onset of veg… but it sounds like u have limited space, so a short-veg SOG style would be ideal, i think… what would be even better if u could setup something to house a cut or two. so u could have a rotating crop and perpetual harvest…
If u can fit a 5gal, then u can fit four 1gallons. run on 2wk cycles. every 2weeks: harvest a 1gal, force a new 1gal, repot a rooted clone into a 1gal and veg, and cut a new clone. so, you’ll have 4 plants in flwer, 1plant in veg, and 1 clone thats rooting. u can do this all in less than 3sqft… that way, you wont run out weed… if u do, the next harvest will be just 2wks away.
Another option would be to simply grow one clone the 5gal for 3 or 4 months and train it into a huge plant, flower for 2months and hopfully you’ll get enough weed to last 6moinths, until the nest harvest.