To prevent skinny stem fall overs ... I plant them in small flower pot when they are seedlings ... I only fill them half way up with soil ... so when they start showing top heavyness, I fill the rest of the flower pot with soil ... covering up half of the stem ... the stem will soon grow roots out of the stem I covered up ... its anchored better and has a better root ball thats deeper.

If you start with a full flower pot, then the root ball with stay close to the surface ... and be prone to top heavyness with poor anchoring ... leaning plants mean there is some roots ripping