What lies below
Snow can be the bane of those of us who live on the prairies. Unless you’re into a sport that involves it, most of us just want to get rid of the stuff. Now there’s even more reason to think about those flakey white crystals this time of year, or more accurately, what lurks beneath them.
The demon that hides under the snow is mould; and its spores, or reproductive cells, can cause real problems for allergy and asthma sufferers. If you’ve ever noticed a whitish-grey fuzzy mat left behind on the ground when the snow melts, you’ve found the culprit.
Snow mould is actually a fungus. It thrives under moist conditions at temperatures between zero and seven degrees Celsius, which is right about early spring here in Saskatchewan. Grey snow mould (Typhala incarnata) is the most common in our area. It usually attacks only the above-ground blades of grass, which may not cause a lot of damage to the lawn, but pink snow mould (Microdochium nivalis) can be much more damaging, as it also attacks the roots of the grass. Fortunately, it’s not as common here as the grey version.
When the snow melts, the fungi release their spores into the atmosphere, where, if breathed in by someone with asthma or allergies, they can cause sneezing, wheezing, itchy eyes and, in more severe cases, breathing difficulties. The Lung Association of Saskatchewan says that reactions to the spores can be especially severe for allergy and asthma sufferers. “[Snow mould] causes an allergic reaction. It can cause a very mild allergic reaction or, in people with asthma where mould is one of the things that triggers that asthma, it can actually be quite serious,” said Jill Hubick, a registered nurse, and health promotion coordinator and respiratory educator with the association.
While it won’t start causing problems until the snow melts, now is the time to take preventative steps. Snow mould doesn’t actually live in the snow, but in the ground just beneath it. It’s killed by warmer air, so ensuring the snow in your yard will melt quickly and evenly in the spring will help both allergy sufferers and the lawn. Don’t let snow build up in large piles and, once the weather warms up, start raking to spread it around. The sooner it all melts, the sooner you can stop worrying about snow mould at least.
Hubick advises people who are sensitive to snow mould to let someone else do the work. “Like anything that makes asthma or allergies worse — a trigger — avoidance is best if possible. If they can, they should avoid outside chores and ask someone else to do them,” she said. People who do have to be outside when the spores may be airborne should consider wearing a mask, Hubick added. And, she reminds them to continue taking their regular medication to control their allergy or asthma and may, in fact, need additional medication. “During periods when snow mould is problematic, their doctor may suggest increasing their everyday asthma medication, and some [people] may also need allergy medication in addition to their asthma medication,” she said. Hubick also reminds people with severe asthma to always carry their “rescue medications” such as inhalers, for emergencies.
Just as there is no cure, only treatment, available for the human reactions to the mould, so too is there nothing available to cure your lawn. None of the antifungal products available for our gardens will work on snow mould; homeowners can only apply a good quality fertilizer in the spring and hope their lawns recover. In severe cases, or if lawns are afflicted with the pink version of snow mould, they may have to be re-seeded.
If you’re concerned about snow mould, the best time to take preventative action is autumn, when homeowners can ensure their lawns are cut short and de-thatched if necessary, and that there are no leaves or other debris on the lawn to encourage mould growth. Other than that, it’s just a question of making the snow go as quickly as you can. To do that, spread the snow around so the drifts don’t pile up too high and it melts quicker. Something we can all hope for!