Not bad at all. They do not look all that small considering that mid-May was 10 days ago.
Judging by the way they look they have really taken off since then.
Yes on what
@GainesvilleGreen brings up about filling the pots as close to the top as possible. When we fill up 2/3 or 3/4 of the way we are reducing the amount of soil that the roots can grow in.
Dream Tiger, one thing I see that has to be checked on are the white areas on several leaves on "One Piece". They show up on the top photo and the photo of the plant by itself. If the second photo is just a crop and enlargement of the first then maybe not a problem. But it looks like the second photo was taken separately and the white areas still show up if there was a different exposure.
Looks like the early start of Powdery Mildew. One way to check is to use a clean damp cloth, any water will do, and try to wipe those areas off. If the white area comes off then a good chance you will have to start a prevention program.