Chrysanthemum’s the Word

A small flock of goldfinches drop out of the sky and one by one they descend into the 6-to-7-foot-high Rudbeckia triloba, immediately disappearing and becoming invisible as the yellow birds merge with the yellow flowers. The only clue of their presence being the occasional rustle of a stem as a goldfinch finishes picking the seeds from the black head of one flower then drops to another inches below.

A few young female ruby-throated hummingbirds busily buzz among the hibiscus, phlox, Rudbeckia and briefly dip into the flowers of Ligularia “Desdemona,” but the adults have long since headed south as have the young males. Where dozens of these amazing birds would gather at my feeders, now it’s just an occasional sip then off for nature’s nectars and some insect treats.

Mum is the word of the season, though, as garden centers, flower shops, big box stores and even supermarkets bring out their potted chrysanthemums for sale. They began showing up in late August, and I was amazed to see folks buying them and planting them right away. Many wilted immediately, and I’m sure some got planted with buyers thinking that for $6 you could buy a large potted mum, plant it in the garden and it would return year after year gracing the late garden with mounds of oranges, near reds, purples, burgundy, whites, yellows and bi-colored flowers.

Why these plants wilt so fast isn’t a secret, and neither is the fact that few will return to flower next year. Yes, you can have mums that will return every year but they’re probably not the ones you’re buying now and may not be the ones you can buy locally. Here’s why.

Chrysanthemums will color up your fall pots, baskets, and portions of your garden but the modern mum, while having perennial roots, is now considered by the horticulture industry as an annual bedding and potted plant. This is obvious when you realize how they are grown and brought to market, but I found another clue when I read the tag of a well-mounded mum in a 12-inch pot at a local market.

This mum is named Stacy Pink, and when I started sniffing around, I noticed that one wholesale grower listed the plant as an annual while others refer to it as a perennial. The tag with the plant tells us to mulch it when the ground freezes but nowhere on the tag is it called a perennial.

Let’s go back many months, probably to a place like Costa Rica or another nearby Central American country. It’s here that these mums are initially grown from stock plants. The tiny cuttings go into tiny cells, and once rooted these flats of about 50 cells with a single rooted chrysanthemum cutting in each are then shipped up to the United States. The cuttings will either go directly to the end grower or to a middle grower who will put several of these small, rooted cuttings into pots ranging in size from 4 inches up to 12 inches and larger. The larger the pot, the more cuttings that go into it.

The “plugs,” as they are called, then go into a very tight growing schedule and regime in which the amount of light they get is tightly controlled as is the amount of fertilizer. They get lots and lots of fertilizer. As the cuttings continue to grow the grower has a schedule that’s been supplied by the plant broker or supplier telling them exactly what to do during the production schedule. They get sprayed with insecticides, though in some cases beneficial insects may be released instead. They get sprayed with growth regulators to keep them compact and tight. They get sprayed with pesticides to manage insects and diseases.

But most important, the amount of light they receive is managed with black-out cloth that’s pulled over the plants so that during this stage of growth flower buds are initiated and the grower can estimate pretty well on the exact week that these plants will be fully budded or in flower and ready for sale.

Essentially, these plants are being forced to flower at a specific week in September or October — and they will. The problem is that if your intention is to have these mums flower again next year at the same time with the same mounding form and shape — they won’t. If they do overwinter, then next year they will inevitably be taller, not as rounded or mounded and you’ll have no idea when they’ll flower until they do. It will not, however, be when they flowered this year.

I say all this not so much to be critical but so that you have realistic expectations about these plants and how to handle them. And the ones that wilt and wither just hours after you get them home? These plants have been grown in the same pots for months and the roots have totally filled the pots. This means they need watering several times a day unless you plant them in planters, much larger pots or into garden beds where the roots will eventually expand and require less watering — maybe weekly instead of daily.

As for insects and diseases on mums that you may hold over from year to year, well, let me relate a short anecdote. While speaking with a plant pathologist about mums when I was putting this column together this pathologist noted that she’d been asked to write a chapter for a book on chrysanthemum diseases. When she had completed her chapter it was so long it wasn’t able to be printed.

There is another side to mums, though, and these are the different classes or styles of chrysanthemums that are used for cutting and display. These cover nearly 25 different classes of chrysanthemums that fall into one of the following categories: Irregular Incurve, Reflex, Incurve, Decorative, Intermediate Incurve, Pompons, single and doubles, Anemone, Spoons, Quills, Spiders, Brush and Thistle, Exotic, Cascades, hardy garden mums, Gnomes and probably a few others.

There used to be several growers in the country that offered these mums so we could add them to our cutting gardens and many garden club members grow them for use in competitions. Kingsmums in Oklahoma has a great selection, and you can find a wealth of information at their website, kingsmums.com. They offer over 160 mums in all the classes noted above — but they are sold out for 2022. If you visit their website early in 2023 they will be accepting orders for spring delivery. Don’t dilly dally as many will sell out quickly.

My favorite chrysanthemum? It’s the only one I grow, and it’s called Chrysanthemum koreanum “Single Apricot.” I keep a stock block about 2 feet wide and 3 feet long and each spring I can easily dig sections from this block and plant them where I’d like them blooming in the fall. I’ve never had a disease or insect problem with this variety, and best of all they are the latest-flowering mum I know of, often flowering late October into November. The plant grows only to 15 inches and never needs disbudding. The flowers are often the last ones visited by honeybees in the late fall.

Another tip if you are able to hold over your mums from year to year: Bedding mums will flower later and be much more compact if you disbud them before July Fourth. As you see the buds begin to develop just roll them off with your thumb. This results in bushier fall plants that will also flower about two weeks later than if not disbudded.

Take a road trip down to the Brandywine Valley in Pennsylvania this fall and see the Chrysanthemum Festival at Longwood Gardens from October 1 though November 13. You’ll leave wanting your own mum collection as this show is nothing short of spectacular.

From October 1 through 30, the Kiku Japanese garden at the New York Botanical Garden in the Bronx has its Japanese chrysanthemum show where you can see mums grown in the Japanese style that have been 11 months in the making.

So, mums the word and now’s the time. Temper your expectations with store-bought mums, but they do have their place when it comes to pot, planter and fall garden color. Broaden your mum horizons, though. Lots of interesting opportunities here even if you just stick with the “Korean Apricot.” Keep growing.

I’m having a little more confidence that we’ll be seeing more rain as we go into the fall. Not lots, but more. This has allowed me to do some spot seeding and overseeding in the lawn, but I’m not going crazy. A couple of weeks ago I mentioned seeing sod webworm moths in my lawn. I failed to mention that there are grass varieties that are very resistant to this moth. These grasses contain a beneficial fungus called an endophyte, and you can buy endophyte-enhanced rye grasses as well as fescues. Jonathan Green has nearly a dozen mixes that contain endophytic grasses, and you’ll see a small gold oval on the package that says “contains naturally insect-resistant grass.” Also ask at your local garden center to see if they have grass blends containing endophytes.

Fall webworms are now showing up in some trees and shrubs. They look like the same tents that we see in the spring from tent caterpillars. These caterpillars can do some serious defoliation, but they tend to be concentrated in small areas and rarely return to the same area the next year. If you find them and are concerned, a spray of Bt or another organic material can be very effective, but only use materials labeled for use on fall webworms.

In the vegetable garden, continue to harvest broccoli. Most varieties will send up second and third heads going into the fall, but if you allow the heads to go to flower, the plants will shut down and no more broccoli. Even if you are getting too much in your harvest, continue to remove the mature heads or the production will simply stop. The same holds true with basil. At this time of the year, it really, really wants to flower. Once it does, the flavor and aroma changes and not always for the better. It’s a losing battle but for as long as you can, remove any flower buds as they appear as well as bud stalks.