(Video of Notorious deck restoration painter Anthony Ford talking about the effects that potted plants have on deck floors and their longterm health)
Lots of People enjoy placing potted plants on their decks, they are enjoyable to look at , some deck owners even go as far as to grow whole miniature gardens on their decks. ( docks, gazebos, patios)
The reality is they really should be placed off your deck unfortunately if your seeking ultimate deck health.
not only does everything you place on your deck cause shadows that keep water and moisture cool and harder to dry out of the wood ( or composite)
but they also end up with water under them , that is almost impossible for the sun and mother nature to dry up naturally and remove before corrosion takes place.
it helps a great deal if you have a super insanely thick deck armor - like Kong Armor
however , even the worlds toughest coatings, and surfaces including composite and pvc - and definetely wood will begin to take on corrosion in their fastners ( screws and nails) when water pools under objects and cannot be naturally cured in a reasonable time.
but we want to use and enjoy our decks right?
so it's reasonable that most people will do this regardless of this knowledge. however, moderation and also innovation can be used by some to overcome these problems...
for example if your going to have potted plants. limit them so u don't have a massive rot situation that develops on your deck.
also I've seen way better results for deck owners who use something that holds the pots up off the decks surface atleast 18 inches to allow the sun to penetrate and adequate airflow... also ...
rotate your plants in different locations to prevent long term shade pockets that cause damage and to prevent water from pooling under them and causing corrosion.
it's also worth noting some of the most significant damage I've seen from plants in general on decks, docks, patios and other surfaces are the seeds and fruits and leaves that fall onto the decks surfaces
they often have natural oils that are acidic and cause rot and fastner corrosion. they also attract birds and bird poop..which is highly acidic.
the less u put on your decks surface the healthier your decks surface will longterm. that's a fact I've found undisputed
over 2500+ Lifetime deck restorations / rescues/ and Deck Armor Painting Projects completed