What Are Those Black Sticky Dots on My Windows?!

Are they bug poop? Fly spots? Holly bush seeds? Jealous neighbor’s prank?

Ever see tiny little black dots covering your windows and stuck to the side of your house? They are annoying, unsightly, and a pain in the booty to get off. Even if you scrape off the hard-outer part, it still leaves a small brown blemish on the surface of your windows and sidings. What exactly are these little buggers and how does one remove and prevent them effectively?

When we moved here to Kentucky we had our first encounter with these little nasties while working on a home. Imagine our dismay when we realized that every window was covered in them and each would have to be carefully scraped off, making sure not to scratch the windows in the process. When we questioned the homeowner, the response was that they were little fly spots. Brrrnn, WRONG!

After some research we discovered that it is called Artillery Fungus. Yes, aptly named because the fungus can shoot its spores at light-colored house-siding, fences, windows, and cars. These tough little fungi grow and develop in mulch made from wood during cool and damp conditions. Also known as “Shotgun” fungus, they can then shoot their spores as high as 20 feet into the air!

Also known as “Shotgun” fungus, they can then shoot their spores as high as 20 feet into the air!

Once attached to your house it is extremely difficult, if not impossible, to remove them. As demonstrated in the video, it usually requires use of scrapers to effectively remove them from the glass. This certainly adds an extra step to outside window cleaning and increases the use of ladders in place of poles.

When artillery fungus is on your sidings, it’s even a greater problem. Even a professional soft wash of your house which will remove most of the organic debris from the sidings will only be effective if the fungus is very very fresh. So, unfortunately, most of the times pressure washing will not remove these pesky things. You will need to scrub with Mr. Magic Eraser (they’re amazing in so many ways!) or use a plastic scraper very gently with lubrication to remove them. Since they can be as high up as 20 feet from the ground, this can be a challenging task! In order to stop further attacks to your house exterior, you can remove the infected mulch from the surrounding areas of your house and replace it with new mulch.

Leave the windows to professionals because you can scrape the spores off your windows, but if not done correctly you could cause harmful scratches and damage to your windows and their seals. Some frustrated home owners even consider moving mulched areas away from the immediate vicinity of their house. If you’re in the greater Lexington KY area, give us Infinity Pro Clean pros a call for residential window cleaning, house wash (soft wash), and any other pressure washing needs. We will be happy to help and share our expertise on the maintenance of your property.