Black Spots on House Siding: Causes, Solutions & Prevention Tips

Black spots on house siding can quickly turn a charming home into a source of concern—yet understanding their causes is the first step toward effective solutions.

Black spots often stem from mold, mildew, algae, or dirt accumulation, especially in shaded, humid areas. Environmental factors like rain, moisture retention, and limited sunlight promote growth, while organic debris can trap moisture and accelerate discoloration over time.

For safe removal, clean affected areas with a mixture of water and mild detergent, followed by a power wash using proper pressure settings. To prevent recurrence, improve ventilation, trim tree branches to increase sunlight exposure, apply mold-resistant sealants, and consider pressure-treated or durable siding materials that resist organic buildup.

If spots persist despite cleaning or show signs of structural damage, moisture intrusion, or extensive mold growth, consulting a professional siding contractor ensures thorough inspection and long-term repair—protecting your home’s value and appearance.

Addressing black spots on house siding is essential for preserving your home’s curb appeal and structural health. With consistent maintenance and timely professional help, you can keep your siding looking sharp and spot-free for years to come.

We have these small, black spots that look like specks of tar all over the white, vinyl siding of our house. It's on the porch, my windows, but it is worse on the siding. It goes all the way up to my second-story windows, and is even under my soffit and on my gutters.

What do you think it is? Sounds like you have the infamous "artillery fungus." See the image for what the spores of the. Remove Black Spots on Vinyl Siding FAQ What is the black stuff on my vinyl siding? Little black spots on vinyl siding are most likely artillery fungus, a very common problem with home exteriors. This fungus is attracted to the mulch in landscaping and it will latch onto buildings.

How do you get rid of artillery fungus spores? Black spots on white vinyl siding, resembling specks of tar, are likely caused by the wood-decay fungus, Sphaerobolus stellatus, or shotgun fungus. These spores are responsible for producing black tar-like spots on vehicles and siding.

These small, black dots can be found on various exterior surfaces, including siding, windows, and gutters. Artillery fungus is a wood-decaying fungus that causes black spots on siding, cars, and plants. Learn what causes it, how to prevent it, and how to get rid of it with professional pressure washing.

Are you noticing small black spots on your home, car, patio furniture, or anything else in close proximity to your mulch beds? If so, you may have Artillery Fungus nearby. Black dots on siding are typically one of two things, mold or shotgun fungus. about both, and how to remove them in this article!

When tiny, sticky, tar-like black spots appear on the siding of our home, on outdoor surfaces such windows, railings, and cars, or on the foliage of landscape plants, you might be inclined to think it's insect droppings or some kind of sap. But the culprit could also very well be the mulch in your yard that is affected by artillery fungus, also known as shotgun or cannonball fungus. It.

How does mold get on the siding of your house? Is it dangerous? If you have water getting trapped behind your siding, here's our guide on what to do. Appearance: Black spots that accumulate on the lower portion of siding, most commonly in areas with mulch beds. Causes: Artillery fungus grows in moist areas at ground level and attaches to and feeds on organic materials like wood chips.

Properties with bulk mulch and significant shade are more likely to experience artillery fungus infestations. The presence of persistent, brown to black spots on cars, house siding, plants, and other surfaces may be an indication of the presence of the fungus Sphaerobolus stellatus. These brown spots, called peridioles or glebal masses, are approximately 2.0 mm (1/12 inch) in diameter and are the dispersal structures of this fungus.