Is the early fall color forecasting a severe winter?

Don Kinzler
Forum News Service

FARGO — Have you heard the latest? Rumor has it that early fall color appearing on some trees and shrubs means the upcoming winter will be brutal, with record-setting bitter cold, and snow depths seldom seen in modern history.

Can this be true? Does the wise old oak tree know something we don’t?

There’s an old saying that suggests if you haven’t heard a rumor by 10 a.m., you’re supposed to start one. That’s perhaps how the bone-chilling winter forecast started.

Weather folklore is fun and fascinating, but it can be problematic because it often doesn’t pan out. Although it makes for interesting small talk, fall color doesn’t predict the future. Instead, the arrival of autumn foliage color is a response to conditions that are currently happening, or have already happened, not future events.

As fall approaches, plants respond to the current shorter days and weakening sunlight and begin dismantling the summer photosynthesis machinery. Chlorophyll breaks down, green pigments fade and other leaf colors are unmasked, revealing leaf pigments such as yellow carotenoids. Trees and shrubs displaying yellow fall color have simply had their pre-existing yellow pigment unmasked by the breakdown of green chlorophyll.

Because these pigments are always present in the leaves, yellow and gold fall colors remain fairly consistent each year because they are triggered by the calendar’s short days. Besides yellow fall colors, some trees and shrubs turn red, orange and scarlet, which depends on the types of plants and the fall weather.

When night temperatures begin consistently dropping below 45 degrees, sugars in plant sap are trapped in leaves where chemical reactions convert sugars into red and purple pigments called anthocyanin. Not all types of trees and shrubs have the necessary building blocks for red and orange pigments, which explains why some types remain yellow. Orange and copper shades are created when newly produced red pigments blend with yellow pigments.

The longest, brightest fall color happens when days are sunny and nights are cool, but frost-free. Sometimes, frost is falsely believed to enhance autumn color, but frost actually shortens the fall display. Too many freezing nights cause leaves to detach from their twigs and fall to the ground. Warm, wet weather often diminishes fall color, which is often intensified in cool, dry autumns.

Why do some trees and shrubs turn color early? The University of Michigan says certain factors can cause leaves to change color early or out of sync with their neighbors, such as trees on the edge of low-lying areas where cooler air collects at night, causing them to display colors sooner. Trees that are stressed or in decline may also display fall colors earlier than their healthy neighbors do.

Early sightings of fall color are often single trees sticking out visually in mostly green stands of trees. The lone tree frequently has been stressed in some way, and the stress might even go back a year or two, such as being too wet or too dry.

In areas where new homes have been built, soil compaction can cause stress that might not show up immediately. Trees and shrubs that have been transplanted within the last few years frequently develop autumn color faster than well-established trees of the same type.

Although it’s fun talk around the coffee shop, there’s no historical correlation between early autumn color and severe winters when examined after the fact. Likewise, a heavy seed set on trees hasn’t correlated historically with the winter that follows, which is another folklore weather forecaster that unfortunately hasn’t proven accurate either.

Fielding Questions: Easter lily rebloom, lawn mushrooms and off-color Thanksgiving cactus

Q: My Easter lily bloomed today! It was a grocery store plant that I set in the ground after Easter this spring. What a beautiful second blooming. — Joyce Duenow, Fargo.

A: Thanks for sharing your success story. Your plant is living proof that Easter lilies can be repurposed instead of discarded, and it makes a fun project.

Lilium longiflorum is an outdoor perennial lily that just happened to be so attractive it was adopted by the florist trade as an Easter plant that could be potted and greenhouse-grown in much-demanded quantities. Like other lilies, it can be grown outdoors as well.

It’s important to note that Easter lilies are one or two winter-hardiness zones tenderer than the other lilies commonly grown in regional perennial beds, being about zone 5. Easter lilies can survive in our zones 3 and 4 if planted in a sheltered microclimate receiving generous snowcover and covered in early November with about 24 inches of leaves or straw as a protective mulch. The first summer in which you plant the potted lily outdoors, the usual bloom time is September. In following years, they’ll flower during July in the outdoor perennial flower garden.

Q: Is there anything I can do about the mushroom problem in my yard? From what I’ve read online, there isn’t much that can be done. We had a very large, messy maple tree that was removed a few years ago. Since then, the mushrooms have appeared and this summer have been really bad, I’m sure due to all the rain. We pull them by hand before mowing to prevent them from spreading any more. Is there any spray or trick to kill them?

A: With generous rain in many areas, it’s been a tremendous year for mushrooms in lawns. I’ve seen some the size of a dinner plate.

Mushrooms are fungi, and as such there are no plant-type herbicides that are effective. Being fungi, wouldn’t a fungicide kill them? Fungicides are mainly preventative, and have little or no effect on mushroom fungi that are already established. On the upside, mushrooms don’t usually harm the lawn. They’re existing on decaying organic material like old roots or lawn thatch and they serve a useful purpose by decomposing materials that improve the soil and release nutrients.

Removing and disposing of the visible mushroom caps, which are the spore-producing structures of the mushroom, can help reduce release of the spores into the surroundings. If mushrooms continue to be a problem, core aerating the lawn in fall or spring can increase airflow into the lawn’s profile and help diminish mushroom growth.

Q: Any idea why my Thanksgiving cactus is turning purple on the ends? It’s 3 years old and always in the north window. — Jan Barker, Fargo.

A: The stem pads of Thanksgiving and Christmas cactuses turn purple or purple-green for several reasons. They often turn reddish-green if the sunlight level is too intense, which obviously isn’t the case in your north window.

Purpling in these holiday cactuses has been linked to a deficiency in magnesium, which can be caused by potting soil that is low in magnesium, or by the plant’s inability to utilize the magnesium that might be present. Slight, subtle changes in the plant’s surroundings can interfere with magnesium uptake, such as temperature fluctuations or cool temperatures.

Look for a water-soluble fertilizer that includes magnesium in the content list, and apply following label directions. Or you can add 1 teaspoon of Epsom salt (magnesium sulfate) to a gallon of water and apply enough to soak the soil once a month, discarding excess drainage. I’d value a progress report in a few months. Thanks.

Does early fall color foretell an early, severe winter? Folklore says yes, but science says no.
A reader was excited to share this photo of their Easter lily having a recent second blooming.