Should I trim my portulaca plants?
This is a personal preference. I trim them when they start getting ratty-looking and to collect seed. Often you can tell where a new branch is emerging from an old stem. Don't cut this off. You can go for a quicker and more drastic cut if there is time for the plant to recover and rebloom before frost. Moss rose loves hot weather and direct sun. If you are in the northern hemisphere, the weakening sun and decreasing hours of daylight mean less vigorous growth in sun lovers. Where I live, frost is due in 3 weeks!