How to Grow: Overwintering Bulbs

Learn how to overwinter common garden bulbs such as gladiolus and dahlias.

Listen to podcast:

Dahlia, Dahlias Bud, Flower, Bud, Dahlia GardenWith our warm, dry summer and fall the subtropical bulbs have been putting on a show. Canna lilies, dahlias, gladiolus, 4 O clocks and other tender bulbs have been growing strong. But with the first frosts of the season rolling through the area, it’s time to dig and store them. These bulbs are not hardy in our area, so it’s either dig and store now, or do like my neighbor is doing. She has so many cannas that she’s going to just let nature take its course and treat them like an annual.

While cannas and dahlias get most of the gardening press, there are other tender bulbs such as tuberous begonias and 4 o clocks that can be dug and stored. Most gardeners don’t realize 4 o clocks form a tuber by late summer which can be dug, saved and replanted in spring. That way you get a bigger and faster growing plant than starting from seed each year.

Once frost has nipped the tops, dig these bulbs, corms and tubers. Cut off the foliage right above the bulb and wash or knock off the soil. Let them dry in a warm garage, barn, or room for a few days.

Each bulb has a little different requirement for storage. For gladiolus, remove the older bottom corm and bulblets and store the newer, fresher top corm in onion bags in a 40F room. Place the dahlia clumps and canna lilies upside down in boxes covered with slightly moistened vermiculite, peat moss, or wood shavings in a 40 to 50 F room. Check them periodically in winter for shriveling or rotting. If too moist, let them air out. If too dry mist them with water. Once dry store tuberous begonias and 4 o clocks in layers in boxes filled with slightly moisten peat moss.

From the Vermont Garden Journal on Vermont Public Radio.

All About Houseplants Webinar

Learn about the best and easiest houseplants to grow in your home with different light, fertilizing and watering needs. These include hibiscus, begonia, monstera, figs and much more.