March 12, 2004 at 8:46 a.m.
So far we have enjoyed a nice winter with plenty of snow, no blizzard and reasonable temperatures. I am also aware that in March and the first part of April the weather can change in a hurry. Whenever the snow melts and spring is on its way, there are a couple of nuisance conditions that can occur. Snow fleas and snow mold may sound bad, but they are both harmless.
Our office has had several calls already this year about an invasion of tiny black insects all over the soil. These tiny, dark, jumping insects are found on top of the snow in late winter and early spring. They are called snow fleas. They actually are not fleas at all, but a type of insect called a springtail that look like a flea when they jump. They are very different from true fleas. Springtails feed on decaying plant matter and are extremely abundant in the soil and leaf litter. They do not bite people or transmit disease.
Snow fleas hibernate in the soil during the winter. When the weather warms and the snow starts to melt, they wake up. Since they have a higher tolerance for colder temperatures than most insects, they are able to move up through breaks in the snow. They are usually found in large numbers, and despite their abundance, snow fleas are harmless. They can be found all the time, especially in the leaf litter under trees, but it is only when they contrast with the snow that we can see how many there really are.
Now that the snow has begun to melt and the temperatures have begun to rise, snow mold fungi may appear in the home lawn. These fungi become active at temperatures near freezing, and typically develop under a blanket of snow on unfrozen ground. Snow mold fungi may continue to infect your lawn after the snow melts for as long as conditions are cool and wet. As the temperature begins to rise and the lawn begins to dry, the fungi will become inactive. Therefore, there is no need for chemical controls. You can rake the infected area to speed drying and wait for the sun to do its job. Proper fall lawn care can help alleviate future problems.
There are two different types of snow mold, pink and grey, and each are caused by a different fungus. Typically you will see circular, straw colored patches of grass. These patches usually appear mottled and are often covered with white, pink or grey fungal growth. You will sometimes see very small mushrooms in the infected turf.
While gardeners wait for the snow to leave, they should be reminded that March is the best time to prune fruit trees. Waiting until it gets warm increases the risk of blight infection.
If you didn’t already preorder your bare root strawberry, raspberry, blueberry and grape plants, there are a limited number still available. Many of these are cultivars developed at the University of Minnesota and used by commercial growers, but hard to find for home use. You can view the order form on the web at: http://www.extension.umn.edu/county/Chisago and click on hot topics. The plant will be available for pick up near the end of April. From this site you can also search for information on a variety of gardening topics by clicking on ‘Ask a Master Gardener’. If you don’t find the answer to your question, you can submit it, and an answer will be posted within a day or two.
Remember, the new voice mail number for our local office is 651-237-3080 and the new email address is: [email protected]. Due to budget cuts, the phone is only staffed 10 hours per week, but the voice mail is checked by volunteer Master Gardeners several times during the week.