Pollen & Honeydew
Pollen and honeydew are two separate sticky contaminants that are constantly blamed on each other. Pollen is the yellow dust that coats Wisconsin cars, siding, and windows every spring from late April to early June — primarily oak, maple, birch, and grass pollens. Honeydew is the clear, sticky, sugary fluid excreted by aphids and scale insects that feed in the canopies of maples, lindens, and elms during summer. Honeydew dries into a lacquer-like film that attracts sooty mold and quickly turns black.
In depth
Both respond well to a standard house wash with surfactant, but they require different timing and technique. Pollen is a one-wash fix; honeydew usually needs a longer dwell and sometimes a follow-up visit to fully break down the sugar. Homes under mature maples or lindens in Madison's older neighborhoods — Nakoma, Vilas, Maple Bluff — often deal with annual honeydew staining on cars, patios, and window sills that is mistaken for tree sap or mildew.
How this shows up on our jobs
We distinguish pollen from honeydew on every quote and schedule accordingly. Pollen jobs get booked for early summer; honeydew jobs get scheduled after peak aphid season and often include a patio or deck.
Services where this matters
Related terms
Tannin
Tannins are natural plant polyphenols — the same compounds that give red wine, tea, and oak bark their characteristic astringent flavor. In exterior cleaning, they are the source of the persistent brown, red, and orange streaking that runs down siding beneath overhanging trees (especially oak, maple, walnut, and cedar) and the rusty shadows that form under wood decks and pergolas. Acorn drip, leaf accumulation, and cedar-shake runoff are classic tannin sources.
Organic vs. Inorganic Stain
Organic stains are caused by living or once-living things: algae, mold, mildew, lichen, tannins from leaves, berry drip, insect excretion, pet urine, and so on. They contain carbon and respond to oxidizing chemistry — sodium hypochlorite or hydrogen peroxide (percarbonate) — which breaks the carbon bonds and destroys the stain at the molecular level. Inorganic stains are mineral-based: rust, hard-water deposits, efflorescence, metallic irrigation over-spray, fertilizer streaks, and the like. They contain no carbon and will not respond to bleach at all — you need an acid or a chelating agent to dissolve the metal or mineral and carry it away.
Atmospheric Fallout
Atmospheric fallout is the general term for the mix of airborne particles that settle on your home over time: diesel soot from trucks and buses, combustion residue from industrial areas, pollen, road dust, wildfire smoke particles, brake dust, and sap aerosols. Individually invisible, cumulatively they build up as a gray or brown haze on siding, windows, and hard surfaces — especially on the sides of the home facing prevailing winds and nearby roads.
Soft Wash
Soft washing is a low-pressure exterior cleaning method that uses biodegradable detergents and a controlled bleach solution to kill the algae, mold, mildew, and bacteria that cause staining — rather than scouring them off with brute force. A soft wash rig delivers cleaning fluid at roughly 60-200 PSI, comparable to a strong garden hose, which is safe on siding, shingles, painted surfaces, screens, and caulking. The chemistry does the work: the solution dwells on the surface, breaks down the organic growth at the cell level, and is then rinsed clean with fresh water.