Why clean your pots?
Pots don’t just hold our plants. They also allow bacteria to grow. Terracotta is worse than plastic for this because it is porous and allows caves for bacteria to thrive.
Salt deposits also tend to grow on the bottoms if water is allowed to sit. This can affect the water quality over time if it sits too long in the saucer.
You should clean off the salt deposits regularly, but the most important time is when you wish to reuse a pot. Cross-contamination is a real problem for plants and growers. While one plant can exist without issue with some diseases, if that pot gets reused by another plant it could kill it.
When to clean a container
The best time to clean containers is as and when needed after emptying and discarding plants but you can clean them outside on a warm spring day before any planting is started. If you leave pots till spring to clean then don’t place them near any previously cleaned pots.
Washing terracotta pots prior to planting also helps to keep soil from drying out during the first crucial day of transplanting. Terracotta pots need a good soaking because if you don’t then they will leach the moisture from the soil you fill it with.
How to clean a container
First off, remove any soil and dirt left in and on the containers. Use a stiff scrub brush and clean warm water (No soap!). Stubborn salt deposits may need to be scraped off manually.
Plastic pots can be sprayed to rinse off any residual bleach and then allow them to dry in the sun. If you have terracotta pots you will need to dowse them in clean water and soak for another 20 minutes to remove the bleach. These will also need to be air dried. They will probably take much longer than the plastic ones.
Don’t soak terracotta pots and leave them out if a frost is likely. Terracotta tends to shatter over time if left out wet.
How to store your containers
Once you have cleaned your pots, keep them away from any unwashed pots, you don’t want to risk cross contamination!
If you need to, place dirty pots in a bag.