Giving the Bulbs a Rest
Summer flowering bulbs such as dahlias, tuberous begonias, canna lilies, and gladiolas have all worked hard this summer producing beautiful flowers, and now it is time to give them the rest so that next year they can put on another great flower show.
All these summer flowering bulbs are considered tender bulbs that are not hardy enough to stay in the ground outdoors over the winter months. After they have been affected by a fall frost they need to be dug up, brought indoors, stored over winter and re-planted next spring. There are different methods for each type bulb.
Dahlias– After the foliage has been touched by a frost, the foliage should be cut back to 15 cm. Carefully lift the tuber out by first loosening the soil around it and then gently digging up the tuber making sure that it does not get damaged. Remove any excess soil from the tuber, then placing it upside down allowing the moisture to drain out of the stem, placing it in a dry, airy, frost-free area for 2-3 weeks until it has dried. After it has dried, store it in a cool (above freezing) dry space for the winter months, checking it every few weeks for any signs of rot. If there is any rot, remove it immediately before it gets a chance to spread.
Tuberous Begonias– should be carefully dug out of the ground after the first fall frost. Place the tubers on a newspaper for a couple of weeks in a cool frost free location and then cut the stems back to 10-15 cm from the tuber, and gently remove excess soil. Continue to keep the tuber in a cool location for a few more weeks until the remaining foliage stems dry up and come off the tuber. It is at this time the tuber is ready to be placed into storage. Fill a container with dry sand or vermiculite and then place the tuber in it. Store the container in a dry, dark, cool (6-10 C) space until February, which is when the tubers can be re-planted.
Canna lilies– After the frost has affected the foliage, cut the foliage back to 12-18 centimetres before digging up the rhizome. After the rhizome has been dug up, air dry it in a frost-free space for a few days and then place it in a container filled with moist sand, peat moss or vermiculite. Store the container in a cool area (above freezing) over the winter months. Check the medium that the rhizomes are stored in periodically for moisture. If it becomes too dry, add a little water to ensure it stays slightly moist.
Gladiola bulbs(corms)- When the gladiola are blooming, remove the finished flowers as they occur before they get a chance to set seed. After they have completely finished flowering, leave the bulbs in the ground until the first frost, which is when the bulbs are dug up and the stems are cut back to 2-3 centimetres from the bulb. You will probably notice that the gladiola formed new bulbs that sit on top of the old bulbs. Keep everything intact at this point. Leave the bulbs in the sun for a few hours, before placing them in a cool (above freezing) area for the next few weeks. Now is the time to remove the new bulb from the old bulb, discarding the old bulb and storing the new bulb. Store gladiola bulbs in an airy container, in a dry warm space over the winter months.
When storing bulbs over the winter, always label them with name, variety, colour, size, height etc., so that next spring you will know what to plant where!
Jos Van Hage owns and operates two Art Knapp Home and Garden Centres in Prince George:
- Highway 16 west at Kimball Road
- Highway 97 North at Northwood Pulpmill Road