Houseplants are the star of January gardening in our part of the world. We have all been cooped up, spending more of our winter days inside with colder weather and shorter days. Most of our trees are deciduous or bared to the elements, without leaves, and the world is less green and more shades of brown and gray.
We humans long for more of the nourishing and renewing green colors of life so we add some foliage plants or houseplants to our lives and look for new plants to add to our interior gardens. Foliage plants not only add color and life to our environment but they add fresh oxygen to our homes and offices. NASA has done a lot of research proving that foliage plants are great natural filters to absorb and process many pollutants that might be in our “inside” air. Plants are not only pretty and calming but actually clean our air and act as little oxygen machines to give us healthy air. We used to be limited to mainly green foliage plants in the low light of our homes and offices but now there are a few plants that even bloom in this low light and many that offer different tones of variegation from white to cream or yellow to add contrast and excitement. Houseplants work well good in small apartments, mansions or offices of any size.
The two main secrets of growing houseplants are light and watering. As a rule, the plants with more “green” or chlorophyll in their leaves like spathiphyllum or Peace Lily plants, ficus robusta or rubber plants, aspidistra or cast iron plants can tolerate lower light. Variegated plants or plants with less “green” and more of the white, cream, yellows or even oranges and reds in their foliage need more light in a spot near windows or in patio rooms. Old-time houseplant growers say the rule for light is that the less green there is in the leaf the more light the plant will need.
Watering is the trickiest part of houseplant success. In low light, our plants work at low speed or have a low metabolism, so they need less water. As the light increases the plant's metabolism increases and it needs more water. A plant in a darker living room might go a couple or more weeks between watering while plants in a patio room with lots of windows may need watering several times a week. Plants in small pots retain less water and will need to be watered more often. Plants in large pots have more soil that holds more moisture and can go longer between waterings. The most common problem with houseplants is over-watering, as folks forget how the low light slows down the metabolism and the drinking and feeding of our houseplants. The best watering meter is your finger. Feel the soil surface and wait to water until the soil is dry to the touch — not dusty but dry. Water thoroughly until water starts to drain out the bottom of the pot then wait to water again until the soil feels dry again. If in doubt whether to water or not, err to the dry side and wait.
Most houseplants survive dry better than wet. Be particularly careful not to over-water if your houseplants are in a pot or decorative container without drainage where the water is not able to drain from the pot.
January is a good time to pick out some houseplants and green up your life.
Rodd Moesel serves on the Oklahoma Horticulture Industrial Council and the Oklahoma State University agriculture dean's advisory committee. Email garden and landscape questions to firstname.lastname@example.org.