The pot and the soil
Every container needs a drainage hole — no gravel layer rescues a pot without one, and the gravel trick actually raises the waterlogged zone into the roots. Bigger pots are easier than small ones: more soil volume means slower drying and steadier temperatures.
Use potting mix, not garden soil. Garden soil compacts into an airless brick in a pot; potting mixes are engineered to hold both moisture and air. Refresh the top third each spring, and repot completely every few years as the mix breaks down.
Watering and feeding on pot time
Pots dry out far faster than ground — daily watering is normal in summer heat for small containers, and the finger test settles any doubt. Water until it runs from the drainage hole so the whole root mass wets, not just the surface.
All that watering rinses nutrients out the bottom, so container plants need feeding where in-ground plants might not: a slow-release fertilizer worked into the mix in spring, topped up with a half-strength liquid feed every couple of weeks during peak growth.
Winter and the two-zone rule
Roots in a container sit above ground and feel winter much harder than roots in the earth — subtract about two hardiness zones for anything overwintering outside in a pot. In cold regions, cluster pots against a sheltered wall, wrap them, or shift the tender ones into an unheated garage once they're dormant.
Frost-proof your pots too: porous terracotta can flake and crack in freeze-thaw climates, while glazed ceramic, concrete, and quality plastics shrug it off. Lift pots onto feet or bricks for the winter so drainage holes never sit sealed against wet pavement.