Spring can bring snow mold to your home’s yard

ST. CLOUD, Minn. — As this year’s snow seems to linger, winter stress in our lawns can be more prevalent. One way that stress manifests is snow mold.

There are two different types of snow mold: pink snow mold and gray snow mold — each caused by a different fungus. Snow mold is caused by three types of pathogens: Typhula spp. and Microdochium nivale. Either of the snow mold fungi typically appears within the home lawn as circular strawcolored patches of grass. These patches usually appear matted and are often covered by white, pink, or gray fungal growth, which has a webby appearance. Pink snow mold produces pink colored spores and pinkish colored fuzzy mycelium while gray snow mold produces sclerotia which appear as dark colored hard bee-bee shaped bodies on the grass blades.

The fungi that cause snow mold to develop become active at temperatures near freezing, and typically develop under a blanket of snow on unfrozen ground. Snow mold fungi may continue to infect home lawns after the snow melts, as long as conditions are cool and wet. As the temperature begins to rise and the lawns begin to dry, snow mold fungi become inactive. Therefore, there is no need for chemical controls — unless there is an area on the lawn where the snow mold appears every year. In severe cases, a preventative application of thiophanate methyl in October or early November may be helpful.

Although the damage from snow mold is seldom serious, there have been years where large areas of lawns are killed. Generally, infected areas are just a little slower to green up. In areas with low mud, gently rake affected areas of the lawn to promote drying and prevent further fungal growth.

To minimize snow mold damage, avoid excessive applications of nitrogen in the fall. If snow mold is common in your lawn, skip the fall fertilizer application. Continue to mow the lawn at the recommended height until it is no longer actively growing. The taller the grass, the more likely it will mat and encourage snow mold.

Do not, however, cut the grass shorter than 2 inches. Grass that is cut too short will be subject to winter injury in the event of a cold, open winter.

This article was submitted by Quincy Sadowski, University of Minnesota Extension. v

Preparing pastures for spring grazing

While it is tempting to open the pasture gate at the sight of green grass, there are several items to consider beforehand.

Take soil samples every three years to determine pH and fertilizer needs. Soil sampling can occur as soon as the frost is out and the ground is dry. You can collect one soil sample per 20 acres of pasture if the management, topography, soil type, and plant species are similar. Sampling should occur from multiples sites within the pasture. You can obtain soil testing kits from your County Extension Office.

Fertilize your pastures. When applying fertilizer, it is best to apply half of the amount in early spring and the other half in the middle of June. The ideal time to fertilize is right before a gentle, soaking rain. Keep horses off the pasture until you can no longer see the fertilizer pellets.

Spring is also a good time to control annual weeds. Mowing is usually sufficient for annual weed control, but you may need to use a herbicide. Always follow the directions and grazing restrictions listed on the herbicide label.

Keep the horses off pastures until the ground is firm and the grass has grown to 6 to 8 inches. Once the grass has reached this height, start acclimating the horses to the pasture in 15-minute, daily increments (15 minutes the first day, 30 minutes the second day, etc.) until you reach five hours of grazing. After that, unrestricted grazing can occur. This gradual transition provides enough time for the horse’s microbial populations to adjust, which reduces the chance of laminitis and colic.

Grazing requires flexibility to respond to plant growth, which depends on weather conditions. Having a dry lot, multiple pastures, and practicing rotational grazing can help buffer adverse weather conditions. Rotational grazing also makes resting, mowing, fertilizing, controlling weeds, and dragging pastures more manageable.

This article was submitted by Krishona Martinson, University of Minnesota Extension. v