Once the nighttime temperatures stay above 45 degrees, it's ok to send your houseplants on a summer vacation. They love being outdoors when the conditions are right! Do be sure to place them in a mostly shady area.
The late springtime is a great time to get them spruced them up, too. Now is the time to do any repotting necessary or add some potting soil to any plants that are showing roots. You can also give them a cleaning with a gentle spray from the garden hose. It's the easiest time to leech them which means drenching them with lots of water to cleanse the soil of built-up salts. They appreciate it!
Vines and plants that could use a pruning will benefit immensely from a good haircut and will grow out beautifully. Fertilizing regularly during the summer will help ensure good healthy growth during this fastest growing phase of the year.
If your plant is placed inside of a decorative pot, it's better to leave the nicer pot indoors. If plants are left inside of those outdoors, they can collect water at the bottom of the pot, after a rain. If the excess water at the bottom of the decorative pot is not removed, your plants may rot. With a little extra attention in the spring, they should grow well throughout the summer with little effort on your part.