If you only change your containers once a year, make it this one.
Autumn in the Upstate is long, the light is flattering, and the plant material is at its best. A fall container planted in early October will still look good at Thanksgiving, which is more than you can say for the summer planting it replaces.
Plant in the first half of October
Not September. Our Septembers are still summer, and anything planted into a hot container spends its energy surviving rather than establishing.
Not November either. The average first frost lands around November 7 in Greenville, and one year in ten sees it before October 24. A plant that goes in a week before that has no time to root.
The window is the first two weeks of October. That gives roughly four or five weeks of warm days and cool nights, which is exactly the condition fall material wants.
What actually works
Croton is the backbone. Nothing else gives you orange, yellow, red and deep green on a single leaf, which means one plant can carry the whole color scheme and everything else can be quiet. It wants bright light to keep that color. In shade it fades toward plain green and the point is lost. It is a tropical, so it is also the first thing to go: once nights settle below 50°F it starts dropping leaves, and a frost finishes it. Worth knowing it is toxic to pets if chewed.
Ornamental cabbage and kale do something unusual: they get better as it gets colder. The centers deepen in color after the first frosts, so they are the one thing on your porch actively improving in mid-November. They also bring a cool gray-green that stops the whole arrangement going warm and flat.
Lemon cypress gives the vertical line. In a pair of urns either side of a door, two cypress do more for the composition than any amount of flowers, because they set the height and let everything else sit below them.
Pansies and violas go in at the same time. They will look modest through autumn, sulk through the coldest weeks, and then be the reason your containers look alive in February.
Mums, with a caveat, below.
The mums mistake
Almost everyone buys mums in full flower, because that is how they are displayed and that is what looks good in the cart.
A mum in full bloom has roughly two weeks left. Buy them in tight bud (they look unpromising, greener, less finished) and you get five or six weeks instead. It is the single cheapest improvement most people can make to their fall containers, and it costs nothing but the discipline to buy the plant that looks worse.
Pumpkins are a design element, not a decoration
The instinct is to put pumpkins on the step and consider the job done. They work much better used to step the composition down: urn height at the door, something mid-height on the step, pumpkins at ground level on the walk.
That gives the eye a path from the door to the street, which is what makes a porch read as composed rather than as two pots either side of a door. It is the trick behind most entries you drive past and think look good without knowing why.
After the first frost
When frost arrives, the croton and mums are finished. The cabbage, kale, pansies and cypress will carry on.
That is the natural moment for the holiday changeover: pull what is spent, keep the cypress for structure, and build evergreen and lights around what is already there. The cypress you planted in October is the same cypress that anchors the Christmas urn.