I'm kinda new to full time gardening, I've always had a green thumb. I'm in zone 9, I started my dwarf marigolds and semi dwarf zinnias early may from seeds in 3 inch pots. They've been in those pots since. Now they're about 6 inches tall. I'm wondering if I should repot them in bigger pots, or if the 3 inch pots are okay.

Details: using ground-in flower and vegetable soil, plastic 3 inch wide and tall pots, I put 1 Jobes fertilizer spike in each pot, I water them from ground level, I rotate them everyday, and when I put them in full sunlight they start wilting (is that because they're still too young?)