Flowering SMALL/YOUNG plants

i have four ice plants growing in my shed at the moment and are doing fine as the pics show...
Basically, my two biggest ones are 6.5 inches and close to 8 inches. the other two are both 4-5 inches tall.
In my grow space, i am not in the position to be growing massive monsters, i just want a few tame beasts!! No need for me to grow them over 3 foot in total, ideally they would be smaller, close to 2.5 feet.
I know that if i was to flower the biggest ones now, they would be just under 3 foot, but would it be a bad idea to flower the two 5 inch plants now? as i dont want the older ones to exceed 3 foot as i have insufficient space, for like i said; monsters!
Will the two small plants be potent still if i flower them at 5 inches, and what kind of height would i be looking at if i did flower them within the next couple of days?

first question to you is how old are they? i would flower plants that are no 8 weeks at least, since plants need at least 8weeks to mature.

next thing would be if you have taken so far a look into topping and LST, which basically tying them down and let them grow in a shape you prefer? that would help with height problems.

if you limited yourself to 3ft height you should be able to grow them to 1ft, in flower they grow then to 2ft maybe 3ft which is then okay with your limits.

id say wait at least till u got at least 6 nodes

mr. shed...

What kind of lights are you using?

There is rarely a need to grow a plant more than 4-12 nodes before flowering. A typical indica plant has 4-5 nodes at 4-5 inches tall..

iloveyou

Experiment and have fun. I let one get about 3 feet and cut her down to a foot. Poured the Fox Farm to her and within a week you should have seen the new growth. Like a massive little bush. Waited another week and more lush green growth. Now she looks like a round like bush. Just put her into flower. Can't wait for the 6th week explosion.