How can I remove Black Spots from my garden patio?
When looking at your patio, slabs or block paving stones do you see black marks. If you are considering cleaning your own patio in Oxfordshire, then read on….
These black marks are organic growth which is often called Black Lichen. Lichens are a symbiont, which means they are two different organisms living together. There is a bit that does the photosynthesis business which is usually some form of algae or bacteria, and this gets into a mutually beneficial relationship with a fungus, which functions as an anchor as well as acquiring minerals from whatever it is the lichen is growing on. The fungus sends little fungus rootlets, known as hyphae, down into the substrate, namely the paving slabs, block paved drive or walling, and such is the tenacity of these things that it is blighters near impossible to shift them.
If you clean your own patio with a home store pressure washer you are only dealing with the surface dirt and grime and not the organic growth that is going on within the patio stone. The regrowth can often be within 6 months and darker in colour and lichens.
So, can you clean these black spots yourself? Some over-the-counter products are often called Ultimate Black Spot Remover, Pro Black Spot Remover, Patio Magic, and more……. most of these products contains small amounts of Sodium Hypochlorite.
Whenever we are requested to clean patios and driveways in Oxfordshire, we always set the expectations when we encounter black spots.
Our approach to removing black spots on stone patio and driveways is to pre-treat with our SoftWash system (SoftWash Systems) agitate the surface with a nylon deck scrubber, then use Stone Health’s DOFF (DOFF) to steam the surface of the stone to remove the dirt, grime and some of the black lichen.
Sometimes a second application of SoftWash may be required. The SoftWash solution contains a biocide element, and this needs time to work. It can take a number of weeks and possibly months for the black spots to reduce in size and appearance. We would never recommend more than two applications within 72 hours.
So, can you remove black spots from my patio?
Short Answer is yes, but not overnight
Remember that your patio has been down for possibly 10 years, all of that organic growth has got well and truly settled and may take time to die off, compared to a patio that has only been down for a couple of years.