GET MUMS IN THE GARDEN
Add some colour for fall
Fall mums provide a wonderful burst of colour in our yards just when many of our other garden flowers are fading. But another wonderful attribute of these late-flowering plants is that they require so little care to continue to look great well into autumn. A single potted, well-grown fall mum demands little more than a place to stay and a good drink of water now and again.
A BIT OF SCIENCE
As most gardeners know, the word “mum” is the diminutive of its proper name: chrysanthemum. 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. On this side of the Pacific Ocean, the fall mum has become the most popular autumn flowering plant in gardens right across North America.
Fall 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 latesummer 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.
One thing that never ceases to amaze me is the incredible number of flowers that a single fall mum can create. Quite frankly, I think that mum breeders may have developed an obsession with astronomical flower numbers. For example, a few days ago I decided to count the total number of flowers on a new variety that we are growing in our greenhouses. The number was staggering, to say the least. I did a little extrapolating of the count of flowers and buds from a region on a single “muffin top” mum and I estimated the total to be around 1,200 flowers! Maybe the breeders have finally reached their floral limit, but over the years I’ve learned not to underestimate their breeding skills.
WHAT SHOULD YOU DO?
Once you’ve found a suitable spot for your fall mum — which is just about anywhere in the yard — all that remains to do is to check the pots for dryness, add water, and enjoy. If you are shopping for fall mums, keep in mind that most of the late-summer and early-fall mums are past their prime now, so shift your focus to the late-fall varieties that are just breaking bud. Late varieties are always the most floriferous, and thus the most spectacular of the three types of fall mums. Plus, they have the longest flowering period thanks to the typically cooler October 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 -5C, 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 will be crushed and branches will break.
One question that I commonly receive about fall mums is whether or not they can be overwintered outside. I have overwintered mums in my yard by transplanting them into my garden in late October, but it’s still a gamble at best. However, if you have a sheltered spot in your garden and you want to give it a try, why not? Just remember that if the mums do survive don’t expect a mass of blooms until much later in the growing season.
Finally, if you’re the competitive type, try counting the flowers on your fall mum. Even if you don’t have 1,200 flowers on your plant, you can tell your friends that you do.
If they don’t believe you, I’m betting that they will have neither the time nor the desire to confirm whether you are telling the truth.