Warning: Cold Spell in the Midwest

For all those with repotted trees (and other trees leafing out) in the cold-frame, there is a cold spell (high will be lower 30sF and low will be upper teens F to lower 20sF) coming through most of the midwest region for the rest of the week. Somehow make sure that the cold-frame stays above freezing.

This is especially crucial for the repotted trees; whether deciduous or evergreen.