Always inquire if the nursery you are getting your plants from are pesticide FREE!! So important. I am not an expert, but I can almost guess Wal-Mart or any plant retailer like that do use pesticide.
Aphids can be an issue but because I checked my plants daily I was able to keep the insect at bay. I just used a tissue and removed them that way. OR a gentle washing with a hose will do the trick too. Invite ladybugs. They love to eat aphids! *smile*