I find April to be the best month to transplant house plants just as they are waking from their winter rest. It can be a messy chore so it is one that I do on a warm day either outside or in the garage.
Shifting plants up to a larger pot one needs to be careful not to “over pot”, using a pot that is too large. Plants should be repotted into pots that are just two or three inches larger in diameter than the original pot. Using a good potting soil is a must and it will take two or three waterings to adequately moisten the new soil.
Plants not being repotted can be brought out on a warm day for cleaning and a rinse down with the hose. I check all houseplants this time of year for aphids, mealy bug, scale, and mites. These critters seem to appear from nowhere as spring arrives. An outside spaying on a warm day of insecticidal soap or horticultural oil will control these pests.
Houseplants thrive on being outside for the summer, a move I make in Mid May after the danger of frost has passed. They do need to be acclimated to the sun and prefer some dappled shade!