Stone patios look great and they hold up outside well, but they sometimes need to be cleaned.* Here are a few tips to help you out:
The first thing you should do is clear the patio of everything that doesn’t move. This will include furniture, flower pots, lighting fixtures etc. Next sweep the patio and give it a once over with a garden hose. This will get rid of the loose dirt.
As for which solution to use, there are a number, but you can’t go wrong using a 50-50 bleach and water solutions, then scrub with a hard-bristled brush. You don’t really have to rinse it, and it might even be ill advised since the solution can kill grass.
There are green methods as well. For instance, white vinegar is popular for cleaning and it has the added property of killing weeds between the stones. Just apply a half vinegar / half water solution to the stone. Some people use a spray bottle. Allow the solution to set and simply rinse. Often scrubbing is not needed, but if there are tough spots you should do so.
Finally, pressure washing is another alternative, but as a rule it only works for mortared stones. Otherwise, the sand in between will erode
After you clean, it’s always a good idea to apply a sealant, which will protect your stone until the next cleaning.
NOTE: some stone have special detergents, so make sure you investigate which one yours uses.