Lawn damage, boulevard trees, and seeding lawns

BY DON KINZLER

Q: Can you help me figure out what’s causing damage to to my lawn? (See photo on page 12.) My neighbor thinks the culprits are voles. If so, what is the treatment? — Enrique G.

A: Your neighbor is right; the winding trails in the lawn are classic vole damage. Voles are short-tailed brown or grayish field mice. They don’t run as fast as gray house mice, and they rarely, if ever, come indoors.

Voles thrive under winter snow, where they feed on grass, making winding channels through the turf. The grass usually fills in and recovers by early summer. Rake the areas well, and sprinkle grass seed if damage is widespread.

How can we prevent vole damage in the future? In the fall, mow lawns shorter than the summer height. Trim edges and along fences where longer grass grows.

Rodent baits can be placed in PVC pipes laid horizontally on the ground in areas of high vole traffic or damage. These bait stations can also be placed around the lawn’s perimeter during summer, where voles frequently hide. Rodent traps are another option, effectively baited with peanut butter or peanuts.

Commercial vole repellents receive mixed reviews, working in some cases, not in others. Fertilizing the lawn in late autumn with granular fertilizer is being investigated as a vole deterrent, based on anecdotal evidence that voles avoid the caustic nature of the granules.

Q: What are the best boulevard trees to plant? Three out of four of the trees I planted last year here in Fargo died. — Kay Z.

A: In any city, the first step is to contact the local forestry department, or other city administration, to check their recommendations or requirements. Many cities have a certain list of trees from which to choose, which ensures that only adapted trees are planted, and can help avoid overplanting the same species, which caused past problems.

Such lists recommended for Upper Midwest boulevards frequently include the following, all of which are well-adapted to North Dakota and Minnesota: Ohio buckeye; Prairie Horizon alder; Dakota Pinnacle birch; hackberry; Northern Acclaim honeylocust; Kentucky coffee tree; Amur chokecherry; ironwood; bur oak; Prairie Stature oak; Japanese tree lilac and its cultivars; linden cultivars; Prairie Expedition elm; and black walnut.

Q: I understand that most people plant grass in the fall of the year. What is the best way to plant lawn grass in the spring? — Alden L.

A: Planting grass seed in the fall before Sept. 15 is highly effective because soil temperatures are warm from summer sunshine, and air temperatures are generally mild. Evaporation is less problematic, making it easier to keep the seedbed moist, and grass seed germinates rapidly, and establishes well before winter.

Spring planting can be highly successful also. Start with a top-quality seed mix that contains at least 50% of Kentucky bluegrass varieties. Avoid bargain mixes with high percentages of grasses that don’t survive winter.

Delay planting until soil temperatures warm to above 50 degrees. The first half of May is a good window for lawn seeding. If grass is sown too early while soil is cold, birds have an extended opportunity to gobble the seed.

Follow the label directions for the amount of seed to apply. Instead of being planted deeply, grass seed is simply spread on the soil surface and rake in. When finished, grass seed should be visible.

Water the soil thoroughly right after seeding, applying at least 1 inch of moisture. Then keep the soil surface darkmoist with frequent sprinklings until grass is visible, green and growing.

Keeping the soil moist throughout the germination period is the key to success. If the soil surface dries out when the seed is sprouting, it can be killed. This might require watering in the morning and evening, especially on windy days. Applying a very light mulch of straw, dried grass or commercially available seed mulch can help keep the soil surface moist. •

If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at donald.kinzler@ndsu.edu. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.