Last spring I bought a lovely pink polka-dot plant, big and bushy and about 20 cm tall. The single plant filled a six-inch pot, and I think it had either been kept over for the winter or else grown from seed planted months earlier.
I was fascinated by the speckled leaves and the plant’s tidy growth habit — a nice mounded plant with no straggly stems or branches. I kept the plant as a potted plant all summer; locating it outdoors on a table where it got full morning and early-afternoon sun.
In the fall I took the plant into the sunroom where I soon noticed that the intense colour of the leaves waned (polka-dot plants like strong indirect light or even some sun), so I moved it closer to a south-facing window. I also noticed that the plant began to send up flowering spikes of insignificant, small violet-coloured flowers. After deciding that the parent plant was on its way out, I knew that if I wanted to save it, I would need to propagate some new plants before the parent plant deteriorated any further.
After some research I discovered that polka-dot plants do indeed have a short lifespan — usually lasting only one growing season so treated as annuals. After it flowers it either dies or goes into a dormant state and is difficult to revive.
Luckily my plant still had a couple of terminal stems that had not been cut back when I brought it indoors. They seemed to be in good shape and did not yet have flowering spikes so I cut them off, stripped off a few lower leaves, and created three healthy-looking cuttings. Cuttings from polka-dot plants take a long time to root — especially in the fall (all plant slips root more quickly in the spring). I used a rooting hormone to promote roots to form and planted the slips together in a six-inch pot, dampening the sterile soilless mix before inserting the cuttings.
I kept this pot in the bright light of my light garden, checking it periodically and adding a bit of water if the soil was drying out, being careful not to keep it too wet. Cuttings that take a long time to root will often rot before they have time to root if the planting medium is kept too wet. For this reason I did not tent the pot with plastic as I often do with other plants. Beginning to think that my efforts hadn’t been successful, (the cuttings soon appeared wilted and looked very sad for about a month), I almost threw them out but I saw no sign of rot at the base of the slips so I kept the pot with the forlorn-looking slips.
Eventually the slips slowly perked up and gradually lost their wilted appearance so I suspected that they had finally rooted. Gradually new growth appeared. The whole process had taken a couple of months but I finally had three small polka-dot plants that looked healthy.
Slowly, during the rest of the winter, the small plants grew and by springtime I had three 10-cm-tall plants to use outdoors. I had not discarded the parent plant — instead, after taking the slips, cutting it right back, removing the flowering stems and just leaving about six-cm stems sticking up from the soil. These stems developed leaves and by spring I had a nice mounded plant.
The polka-dot plant is quite easy to grow, likes porous soil that is kept moderately moist, and recovers quickly from wilting if the soil dries out. I use soluble 20-20-20 fertilizer during the growing season.
The most popular colour is pink dots on a green background but there are varieties with both red and white spots. The leaves will become solid green if the plant does not get enough light so the intensity of the colour can be manipulated by varying light levels. They are available in garden centres as bedding plants in the spring and can be grown from seed started indoors in early spring — an easier way to obtain plants than my overwinter project.
If you want a showy little plant that serves as a colourful indoor potted plant or a good contrasting plant outdoors, give polka-dot plant a try. Maybe you’ll be so enamoured with it that you too will try propagating some new plants during the winter.