Charleston's spring pollen drop leaves a yellow film on every exterior surface. Here is the post-pollen cleanup checklist that puts the house, roof, gutters, driveway and patio back in order before summer humidity sets in.
Short answer: the post-pollen checklist for a Charleston home runs in this order — clear the debris, then soft-wash the walls to kill the living film and lift the salt haze, then handle the roof streaks, gutters, driveway and patio while the crew and the water are already on site. Timing matters more than force: once the oak and pine pollen has finished dropping, the clean holds through the humid summer; do it mid-drop and you are washing a surface that yellows again inside a week.
Charleston does not get a single clean sweep of weather that resets the exterior. What it gets is a heavy spring pollen load from live oaks, pines and sweetgum, and that drop lands as a tacky yellow film across siding, roofs, concrete and glass. It holds moisture against the surface, which feeds the green-black algae and mildew the Lowcountry already grows in shade. The practical rule is simple: time your exterior clean after the pollen has finished falling, not during it. Wash mid-drop and you are spending money to clean a surface that will be coated again in days. Wait until the drop tapers, and the same wash carries you through the hottest, most humid part of the year.
The order is not cosmetic. Do the flatwork first and you rinse pollen and grit onto a clean wall. Do the gutters last and you leave dirty water running down a freshly washed fascia. A real post-pollen visit is sequenced, and the sequence is what protects the result.
Each surface has its own problem and its own fix — the checklist works because it names them separately instead of pretending one pass solves all of them.
You are killing the living film and lifting the salt haze. The green that shows up first on the shaded north wall and behind the piazza is algae and mildew in the surface, and it comes off with a low-pressure soft wash and the right dwell, not with a high-pressure blast that drives water behind clapboard or carves soft old brick. The dull, chalky film on a harbor-facing elevation is mineral salt from the air, and it needs a surfactant and a rinse that carries it off rather than a wipe that smears it. A wall washed after the pollen drop holds into summer; a wall washed mid-drop is yellow again in a week.
The streaks are living growth, not dirt. No-pressure treatment kills the colony in the granules; pressure strips the granules and does permanent damage. On a historic-district roof — slate, metal, tile, copper — the method is even more conservative, because a single wrong pass on an irreplaceable surface is a repair bill rather than a cleaning. If the roof is already granule-lean or past its service life, the honest answer is that cleaning is cosmetic and the money may be better spent on a replacement conversation.
Two jobs here, and they are not the same. A gutter cleanout clears the leaves, pine straw and catkins out of the trough so water drains — that is the twice-a-year maintenance the oaks and pines force on every Lowcountry home. A gutter brightening removes the black oxidation stripes from the outside face of the gutter — a cosmetic-to-structural finish, not a debris removal. They are priced separately, and you should know which one your gutters need before you book.
A flat surface cleaner is what keeps a slab uniform. A handheld wand leaves the zebra-striping pattern that reads as dark-and-light arcs the moment the concrete dries, and it scours the cream off the top of the slab so the aggregate underneath grabs dirt faster from then on. Pollen, algae film and surface grime come out with the controlled pass; oil that has soaked in and rust bleeding up from rebar are conditions of the concrete, not surface soil, and they do not come out with a wash. A sealer on a clean, fully dry slab locks the surface down and makes the next clean easier and longer-lasting.
The same shade-and-humidity combo that greens a wall grows on a deck, a paver patio and a pool surround — and around water, slick growth is a slip hazard, not just a cosmetic problem. Wood and composite want a gentle clean with the right chemistry; pavers need the joints worked as much as the faces; flagstone and travertine need particular care because they pit under aggressive pressure. Sealing helps on pavers only after the joints are refilled and the surface is dry.
The window is after the pollen drop finishes, which in Charleston is usually late spring — often late May or early June, once the live-oak and pine load has tapered. That is the single most useful clean of the year, because it lifts the layer that has been building since before Christmas and sets the house up for the humid summer. A second pass in the late fall clears the summer's salt film, the summer growth and whatever the early-winter rains brought down, so the property goes into the lower-sun season as clean as possible. Homes under heavy tree canopy, close to the marsh, or with shaded north walls may want a third touch-up mid-summer — the practical test is the same one for any surface: if the green is clearly established, it is time, not a fixed calendar date.
A good post-pollen read takes five minutes from the street and tells you what the job actually is.
What you see from the street is usually what the quote should be built on. A proper quote names the actual surfaces — the slab, the apron, the gutters, the roof, the deck, the pavers — and prices each one flat against that scope. The number should not move because the back wall turned out heavier than it looked from the driveway, and anything a wash will not fix should be told to you before the work is booked, not after.
The reason the post-pollen checklist is one visit rather than six is that the surfaces share the same cause — moisture, shade and salt — and they share the same window. A crew that is already on site with the water managed, the planting wetted and the runoff planned can wash the walls, treat the roof, brighten the gutters and clean the hardscape in one setup, and each line is cheaper booked together than apart. The same visit is also when you find out whether anything is a repair decision rather than a cleaning outcome — failing mortar, rotted fascia behind the gutter, a roof past its life — and the honest crew tells you that before you are billed, not after.
The full picture of what drives the price of all of this in Charleston — the flat numbers, the factors that move them, and which stains actually come out — is in our Charleston pressure washing cost guide. The gutter cleanout specifically is walked through in our Charleston gutter cleaning cost guide. And the reason the timing matters — why the spring drop is the event that sets the whole year's exterior schedule — is covered in our guide to what to wash after Charleston pollen season, which is the companion piece to this checklist.
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