There’s something warm and inviting about a well-placed, thriving houseplant. Experts call this “interior landscaping,” and it’s becoming increasingly popular, not only in homes but in offices and other commercial settings. I would have assumed that’s because houseplants can be quite inexpensive. But now, we’re learning that houseplants offer surprising physical and mental benefits as well. No. 1: Clean Indoor Air A number of studies reported by NASA give conclusive evidence that plants are excellent at removing toxins from the air—over 80 percent of volatile organic compounds (VOCs) every 24 hours. VOCs are chemical compounds often found in common household items such as carpets, toys, paint, and more. These VOCs can evaporate and compromise air quality, posing health risks to inhabitants. One large plant—or two smaller plants—per 100 square feet is recommended for noticeably improved air quality. No. 2: Regulate Temperature and Humidity It’s pretty well known that planting shade …