Q.impatiens
I grow impatiens in pots under my patio (mostly shade). The impatiens have white dots on them. What is the cause and how can I correct it?

Your plants may be affected by a fungus or spider mites. White flecks or webbing on the underside of the leaves are good indications of spider mites. The leaves of impatiens will begin to look gray or bronze in color as more damage is done. A heavy infestation will cause leaves to die and drop off. You can use neem oil to kill spider mites and relieve any fungal issues as well. Here is additional information that may be helpful: https://www.gardeningknowhow.com/ornamental/flowers/impatiens/impatiens-problems.htm
https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm