Mum’s the word for late fall flowers
If you think you have a ‘black thumb’ a surefire way to turn it a bit green this fall is placing a few garden mums in your yard or on your balcony.
Yes, I know that you really aren’t growing the mums — just adding a bit of water here and there — but who cares? They look spectacular and might just be the best ‘gateway’ plant that will ease your fear of killing your plants.
If nothing else, fall mums will provide a massive display of brilliant flowers as your other garden plants slowly fade.
A BIT OF SCIENCE
‘Mum’ is just a quick and easy way to refer to a member of the chrysanthemum family. Chrysanthemums are indigenous to regions of East Asia and were first cultivated a few centuries ago in China. In Japan, they were so highly revered that they became part of the official imperial seal of the emperor. Today, thanks to a lot of breeding work, the garden mums have acquired a ‘muffin top’ shape, with the top dominated by masses of flowers.
Garden mums are divided into three rather broad categories based on their flowering period: late summer, early fall or late fall. All of the mums in each of these groups are referred to as ‘short day’ plants, meaning that they require a few weeks of exposure to a continuous string of short days (less than 12 hours) before they are capable of blooming. For growers, this means that the late summer varieties must be covered with black fabric or black plastic every night for about six weeks to ensure that the plants will bloom by late summer. Missing even a single night of covering can prevent blooming.
Few plants can match garden mums for sheer flower number. The numbers on some of the larger mums is staggering, to say the least — anywhere from 500 to well over 1,000 flowers on a single plant is not unusual. I’m not sure if the garden mum breeders have reached their floral limit but I think they are getting close.
WHAT SHOULD YOU DO?
Because garden mums are so colourful and many varieties are so wonderfully fragrant, it’s best to place them in ‘high traffic’ spots. Don’t worry about sunny versus shady spots. Garden mums have finished growing when you purchase them. All that remains for you to do is to check the pots for dryness, add water and enjoy.
If you are shopping for garden mums, keep in mind that most of the late summer and early fall mums are past their prime now, so shift to the late fall varieties that are just breaking bud. Late varieties are always the most floriferous of the three types of garden mums. Plus, they have the longest flowering period thanks to the cooler fall weather.
But while cool weather is good for increasing mum flower longevity, really cold temperatures can damage flowers. If temperatures are going to drop below about, say, minus-five degrees Celsius, I like to drape a very lightweight, white frost blanket called ‘crop cover’ over the flowers to protect them. Never use heavy blankets, otherwise the flowers and branches could be crushed and break.
Overwintering of garden mums in your yard is possible but not guaranteed. It’s still a gamble at best, but I have had some success in sheltered spots in my garden. If you’d like to give overwintering a try then go for it, just remember that if your mums do survive you shouldn’t expect a mass of blooms until much later in the growing season.
For those who are hesitant to ‘grow’ a spectacular garden mum in their yards this fall because of ‘black thumb syndrome’ consider this. If you’ve managed to keep your cat or dog hydrated for that last few years, then keeping your mum hydrated will be a breeze. Jim Hole is the owner of Hole’s Greenhouses in St. Albert and a certified professional horticulturist with the American Society for Horticultural Science.