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    Save the Date: Perennial Plant Society’s 30th Plant Sale is April 4, 2020, 9 a.m. – 1 p.m. at the new Expo 3 Building at The Fairgrounds Nashville. Here’s where you can find the newest varieties of perennials, shrubs, vines and annuals from local growers, along with long-time, never-fail favorites, ready for spring planting. Learn more at the PPS website.

     

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Leave gladiolus in the ground?

We planted gladiolus in the ground and in containers this summer. I’ve heard they need to be dug up and stored over the winter. Really?

glads orange garden benchGladiolus are tender summer-flowering plants that grow from corms, and where you live will probably determine whether to dig them up or not. Here in Middle Tennessee (Zone 7a), the recommendation from the University of Tennessee Extension is to dig up and dry the corms after the foliage dies back and before a heavy frost, but the truth is, most gardeners I talk to here leave the corms in the ground and they usually survive.

In colder areas, they should be dug and stored. The Web site of the Purdue University Cooperative Extension Service (in Indiana) for example, says that gladiolus corms should be dug after frost. Dig the corms by loosening the soil so that you can pull the plant out of the ground. Shake off the loose soil and allow the corms to dry in the sun for a day or two. Cut the foliage off 1 – 2 inches above the corms and store them in a cool, dry place.

Plant the corms again after the soil has warmed up, in late April or May. By planting in two-week intervals between May and July, you can have a succession of blooms for several weeks beginning about mid-summer.

Cannas multiply, time to divide

Question: I planted cannas several years ago and they have multiplied. I’d like to move some of them to a different location. When is the best time to transplant them?

CannasIn the University of Tennessee Extension Master Gardener Handbook, cannas are listed among the “tender bulbs and bulblike plants” along with caladiums, dahlias and gladiolus. At one time, it was recommended that these tubers be dug up and stored to protect them from the cold, but most gardeners in Middle Tennessee (Zone 7a) now find that they make it through winter just fine, especially if they spend winter under a blanket of mulch.

If you want to move them, an opportunity for doing so is coming up. According to the handbook, cannas can be dug in the fall after the foliage has been killed by frost. Allow the tubers to dry for a couple of days, then store them in a cool location (50 degrees or so – a garage or basement, perhaps) where they won’t dry out completely. The Old Farmer’s Almanac suggests storing them in peat moss or wrapping them in newspaper, and sprinkling them with a bit of water every now and then during the winter. Next spring, plant the tubers in a sunny spot when the soil has warmed to 65 degrees.

You may also wait until spring to divide the tubers. Mark their location now, and in the spring, use a garden fork to dig carefully and lift the tubers from the ground. Separate them, cut off any rotten or diseased bits, and replant them. Cannas do best in a location where they receive full sun.