Our houseplants are all back inside for the winter, or we’ve already lost them to the cold. Been there, done that. Inside or outside we still must be mindful of the underlying factors behind “Right Plant, Right Place, Right Time” and make sure we are matching the environmental conditions that are available to our plants’ specific needs. Light, water, temperature are a few of these factors to figure into our indoor landscape. Humidity (or the lack thereof) is another big concern for inside plants. Our homes are designed for people, not plants and the winter heating system may remove the humidity – the % of moisture in the air – that plants were accustomed getting from our humid NC summers, or that they received in the greenhouse they were grown in.

Houseplants don’t actually grow very much during winter months so we have to treat them differently to keep them healthy. Root rot is a common indoor plant disease issues for houseplants at this time of year and is associated with overwatering. Root rots are caused by several fungal and fungus-like organisms such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. These pathogens are very happy in wet, poorly drained soils and potting mix, and they attack the root system of stressed or weakened plants. Plants should always have good drainage, especially if they are in a container. Check the drainage hole to make sure it hasn’t gotten clogged by roots. Pots wrapped in waterproof foil or placed in deep planters should be checked occasionally for standing water.

Stress makes plants easy targets for attack from disease infections and pest infestations. Varying between extreme conditions results in stressed out plants. It makes perfect sense when you think about it, who likes sudden, dramatic change?

Look for wilting bottom leaves that may continue upward until total plant gives up. Often folks mistake the wilting for lack of water, and add more water or fertilizer to the plant. It is really important to inspect the root system condition and potting mix moisture level before adding more water! A healthy root tissue should be firm, white, and show lots of thin feeder roots. In contrast, rotted roots are mushy and have a brown or reddish color.

Although all houseplants grow best with good care, a few tolerate abuse better than others. Some of the most durable houseplants are; Snake plant (Sansevieria trifaciata), Heart-leaf philodendron (Philodendron scandens), Golden pothos (Epipremnum aureum), Corn plant (Dracaena fragrans), Janet Craig dracaena (Dracaena deremensis), Baby rubber plant (Peperomia obtusifolia) and the Spider plant (Chlorophytum comosum).

If you’re concerned about overwatering consider plants that can handle it – plants that are found in bogs or terrariums such as the Baby’s tears (Soleirolia soleirolii) or prayer plants (Maranta species). Boston ferns (Nephrolepis exaltata) love humidity and will be happy if you never let their roots get dried out. Dwarf Egyptian papyrus (Cyperus papyrus) can add a bit of the unexpected indoors too.

A useful Guide for Diagnosing Houseplant Problems can be found onlione and our friends at the University of Clemson have a very useful publication about the various plant problems and products available to homeowners to address them.

Minda Daughtry is the Horticulture Agent for North Carolina Cooperative Extension in Lee County.