Gardening in the Dirt in Winter

Connie Holland
Adams County Master Gardener

Until recently, the unusual warmer than normal weather made some outdoor gardening possible. Now that the cold weather finally is here, we must turn to indoor activities in order to get a "gardening fix". Garden catalogues are starting to fill our mailboxes with tantalizing photos and descriptions of new plants, bulbs and seeds to try. That activity satisfies one only so long. I know that I need to get my hands in some "dirt" to be happy. (My excavator neighbor, Leonard Shealer, used to tell me that dirt was on your kitchen floor and what we were digging around in was "ground".) Either way, I need to get my hands in it.

Plants overwintered indoors provide an opportunity to get one’s hands in that dirt. I overwinter my collection of tender cacti and succulents in addition to other tender plants. Thirty-five different species of cacti and succulents spend the winter in my basement workshop under artificial lights. These plants normally spend the rest of the year outside in pretty much full sun, so keeping them happy during the winter can be a challenge.

Through experimentation, I found that these succulents and cacti survive winter best under fluorescent lights kept no more that 24 to 30 inches above the plants. I do not use anything special to house them. My plants sit on trays on a large table under four 48" fluorescent double-tube fixtures on timers. At this light intensity, the succulents do not become leggy and the cacti receive enough light to keep their shape. In fact, I find that some of the succulents are happy enough to actually bloom during the winter. Right now there are Haworthia, White Fox Aloe and Gasteria in bloom. Interestingly most of my various succulents bloom with a single, rather tall stem, bearing pendulant peachy-orange flowers at the tip. (See White Fox photo.) In contrast, the Haworthia’s blooms are tiny white curly flowers all along a tall stem.

Outside plants wintered indoors need attentive care during the winter. Unfortunately aphids, soil gnats and mealy bugs can pop up as indoor pests. Their eggs get carried inside in the plants’ potting soil and are triggered to hatch by the warmer indoor temperature. Aphids can appear like magic weeks after a plant is brought inside. Mealy bugs can become a persistent problem due to their habit of hiding in tight leaf folds. Hand removal and alcohol on Q-tips can keep them under control. Do not spray pesticides indoors. If absolutely necessary, do so outside and always read the label and follow label instructions.

Other plants and tender perennials that prefer full sun can survive the winter if positioned near a southern or western facing window. Even potted herbs such as rosemary will grow well if careful attention is paid to not over watering, often a cause of plant fatality. Over watering is especially hazardous to the succulents and cacti. In fact, I inadvertently over watered a Life Saver cactus (Huernia reticulata) causing its center to rot. Currently it sits out of the pot drying on newspaper to try to save most of it from dying!

Having some potted plants to over winter inside gives us gardeners the best opportunity to stay in touch with what we love most – digging in the dirt. Another activity that fulfills that need is grooming our houseplants. They certainly benefit from our attention to dead leaf removal, pruning to improve shape, repotting, and inspection for disease or pests. There are almost unlimited varieties of houseplants that thrive in bright sunny windows to keep us happy gardening in the dead of winter when we long to get outside and dig in that dirt.

Read other winter related gardening articles

Read other articles by Connie Holland