While standing near freezing drizzle Friday, Wilm explained why to PR-B students of all ages as they prepared to plant more than 1,000 trees on school grounds.

Extreme heat is stressful on the trees, he told chilly but eager planters. The ground would also be easier to turn because of the moisture.

Kindergartners through high school seniors gathered near the football field to dig holes and plant Norway (red) pine and white cedar in a combined celebration of Arbor Day and Earth Day Friday, May 2.

For many years Wilm has brought good planting techniques and tree spades to PR-B.

After the brief lesson, students teamed up to share a spade and planted the trees from the DNR's Badoura nursery.

In another Arbor Day activity at the school, students decorated paper bags at local grocery stores Carl's Market, Jerry's SuperValu and Godfrey's.