“Full sun” on a plant tag means six or more hours of direct sun. “Part sun” means three to six. Those numbers are useless until you know what your porch actually gets, and most people guess wrong, usually in the optimistic direction.

The fix costs nothing: pick a normal day and look at the spot every hour or two. Note when direct sun first hits it and when it leaves. That one day of observation will save you a summer of watching the wrong plants sulk.

Morning sun and afternoon sun are not the same

The tag hours don’t distinguish, but your plants will. Morning sun is gentle: the air is cooler and the light less intense. Afternoon sun in a Greenville summer is a blowtorch. Four hours of morning sun and four hours of afternoon sun are technically both “part sun,” and they will grow completely different plants well.

East-facing: morning sun, afternoon shade. The kindest exposure on the porch; many “part shade” plants are at their best here.
West-facing: afternoon sun at full strength. Treat it as harsher than the hours suggest, and pick plants advertised for heat, not just for sun.
South-facing: the most total sun. True full-sun territory unless something shades it.
North-facing: little or no direct sun. Shade plants, and there are more good ones than people think.

Bright shade is not deep shade

A covered porch with an open southern view can be quite bright all day without a minute of direct sun. That is bright shade, and it grows a decent range of plants. The same porch facing a wall of trees is deep shade, which grows a much shorter list. If you can comfortably read a book there at noon without squinting, call it bright shade.

Brick, concrete, and the heat you can’t see

Light is only half the reading. A planter sitting against a west-facing brick wall, or on a concrete pad, gets the sun’s hours plus the heat those surfaces soak up and radiate back into the evening. Plants that handle the light fine can still cook from below and behind. If the wall is too hot to hold your hand against at 5 p.m., factor it in: choose tougher plants, use a bigger pot, or pull the planter a foot or two away from the wall.

The overhang changes everything

A roof overhang doesn’t just block light. It blocks rain. A planter tucked under the porch roof can go bone dry in a week of daily thunderstorms while the pots on the steps drown. Whatever the light reading says, planters under cover are on you to water, every time.

Once you know what the space really gets, the planting follows: our summer guide covers what thrives in each exposure once the heat arrives.