I can't believe those plants actually grew inside of those cups. You're trying to skimp out on a decent pot for your plant/s? Come on!! They are cheap and you can even find them all around your neighborhood. If you're not willing to invest some time in looking for a decent pot you shouldn't even be growing. I don't mean to be harsh but it's the least you can do. Alright I understand it's an idea but you say it's not for you but for your cheap friend so I stand by what I said. Anyways, I don't know how those people achieved what they did in those small cups but a rootbound plant is not a happy one.