How long in a Solo Cup?

My nephew grows outside and bred some photo seeds. He asked me to sprout and sex some to get a start on his outside grow (He's aiming for May 20 to plant).

My question is can I get them to grow and show sex in a red solo cup or will I need to transplant into half gal or?? larger pots after about ?six? weeks?

I'm doing aeroponics myself and not soil, so it is a bit inconvenient, but he gave me some samples to give him a smoke report on the parents.

You can keep a seedling in a red party cup from quite some time. You can veg in it for a month or two...The major noticeable downside is that it needs to be watered very often once it has become root bound.

There are people here who do a Red Party Cup Challenge (grow in a cup from start to finish).

As for if it will extend the time it takes to pre-sex, I do not know the answer to that.

you can grow them for ages in the solo cup. When they are sexually mature (staggered nodes approx. 3 weeks in) take a cutting and put in a glass of water under 12/12. It should survive long enough to show sex. (so I'm told)

Let it dry out enough so you can pop the whole plug out of the cup.
If you can see any roots, pot up.