If you have houseplants that you want to transfer into a new pot, this is the perfect time to do it.  Plants thrive better when they are periodically re-potted with fresh soil.  Pinch back houseplants near the end of March to thicken them and generate new growth.  Misting and spraying your houseplants down will help prevent dust and spider mites.  Watch for pests so that you can cure the problem before it gets out of hand.