The short answer
Trees deposit three unrelated stains: sap (a sticky resin needing solvent action and patience, never scraping), pollen (a film that rinses easily but returns until the drop ends — timing beats effort), and tannin (brown bleed from leaves and bark steeping in water, which lifts with oxidizing chemistry, not pressure). Matching the removal to the deposit is the whole game.
Three Stains That Only Share an Address
Orchard country like Washington Township puts homes closer to more trees than anywhere else we work, and the trees send three completely different problems down onto the housing below. Owners tend to fight all three the same way — hose, scrub, frustration. Each has its own answer.
Sap: The Solvent Problem
Conifer resin and the honeydew drip under maples land as sticky droplets that grab airborne dirt and cure, over weeks, into amber-hard spots. Two rules. First: never scrape or power-blast cured sap — on vinyl it gouges, on paint it lifts the coat with the spot. Second: sap is a solvent-and-dwell job, softened chemically and floated off gently, sometimes over two passes. Fresh sap surrenders in one visit; a summer's cured drip line takes patience but comes off clean.
Pollen: The Timing Problem
The yellow-green film of May and June is the easiest removal on this list — mild detergent, low pressure, gone. The mistake isn't method, it's calendar: wash during the drop and the film is back in days, which converts a win into a subscription. Mid-drop, limit yourself to rinsing sills and entry areas for allergy relief, then take the full wash after the release ends. Pollen's one lasting harm is as a nutrient layer — left through a humid summer, it feeds the algae that IS hard to remove.
Tannin: The Chemistry Problem
The brown tea-stains running from packed gutters, from leaves matted on rooflines, from bark mulch splashing the skirt — that's tannin, the same compound that colors steeped tea, extracted from plant matter by standing water. Pressure does nothing; the stain is chemical, in the surface. It lifts with oxidizing house-wash chemistry (the chemistry guide explains the family), and prevention is mechanical: clean gutters and cleared rooflines stop the steeping in the first place.
The overhang tells the story. Sap spots under the pines, tannin ribbons below the gutter seams, pollen film on every horizontal — an experienced crew reads your trees in the stains and prices the right chemistry for each, not one generic "house wash" for all three.
The Bottom Line
Match the fix to the deposit: solvents and patience for sap, calendar discipline for pollen, oxidation chemistry for tannin. All three are routine for a professional wash — and all three get harder every season they're left to cure, steep, and feed what grows next.
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