17 June 2026 · Patios and Paths
How to get black spot off your patio (and keep it off)
If your patio is covered in little dark, almost tar-like spots that won't scrub off, you're not looking at dirt. You're looking at black spot lichen — and it's the single most common thing we get asked about across Lincolnshire.
The bad news: a normal jet wash on its own won't shift it. The good news: it can absolutely be removed, and kept off, when you go about it the right way.
What black spot actually is
Black spot is a lichen that bonds itself onto the surface of natural stone, concrete and porcelain paving. Unlike moss or algae, which sit on top of the surface, lichen grips into it. That's why blasting it with water just polishes the edges and leaves the spot behind.
It loves the same conditions most Lincolnshire gardens offer in spades: damp, shade, and a bit of organic muck to feed on. Patios under trees or on the north side of the house get it worst.
What doesn't work
- A pressure washer alone. Even a powerful one mostly bounces off it.
- Bleach. It lightens the spot for a week or two, then it's back — and it can damage planting and discolour some stone.
- Scrubbing by hand. You'll be out there a very long time and barely make a dent.
What does work
The reliable approach is a two-stage one:
- A proper deep clean to lift the moss, algae and surface grime first.
- A dedicated lichen treatment left to dwell, which breaks the bond between the lichen and the stone so it can be cleared and rinsed away.
Done properly, the patio comes back to its original colour — and because the treatment kills the spores rather than just hiding them, it stays clear far longer.
Keeping it off
- Keep the surface clear of leaves and debris through autumn and winter.
- Cut back overhanging branches so the patio gets more light and dries out.
- A periodic maintenance clean (every 1–2 years for most gardens) stops it taking hold again.
When to call someone in
If the spotting is widespread, or the patio is natural stone or porcelain you'd rather not risk, it's worth getting it done professionally — the right treatment and the right pressure for the surface make all the difference. It's one of the patio and driveway cleaning services we're asked for most.
We cover Lincoln, Sleaford, Metheringham and right across Lincolnshire for exactly this kind of job. Get a free quote and we'll tell you honestly what your patio needs.
Frequently asked questions
Does bleach remove black spot from a patio?
It lightens the spots briefly but doesn't kill the lichen, so they return within weeks — and bleach can harm nearby plants and discolour some stone. A dedicated lichen treatment is the lasting fix.
Will a pressure washer remove black spot on its own?
No. The lichen bonds into the surface, so water alone just polishes the spots. You need a deep clean followed by a proper lichen treatment.
How long does black spot removal last?
When the spores are killed rather than just hidden, a treated patio usually stays clear for one to two years, especially with the odd maintenance clean.
Need a hand with yours? We cover Lincolnshire for patios, driveways, paths and more — see the areas we cover or browse our services. Get a free quote or call 07874 010739.
Keep reading
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