Q. What is a soilless potting mix, and when do you use it?

A. Soilless mixes are combinations of peat moss, vermiculite and perlite. They are lightweight, sterilized and well-suited for the common foliage houseplants. Regular garden soil is not recommended for houseplants since disease and insect problems often accompany this soil when it is moved indoors. Some soilless mixes also include a slow-release fertilizer. If none is included, you might want to mix a very dilute liquid solution of a balanced houseplant fertilizer into the plant’s regular watering schedule since soilless mixes contain fewer nutrients than are found in good garden soil.