Ashes to ashes
Just a reminder, ash trees, particularly green ash, suffers two spring problems, anthracnose, a fungus disease of the new foliage, begins as a series of speckles on the leaves, progresses to black leaf curling, and ends with leaves falling from the tree. This can be quite dramatic. Treatment is difficult, requiring preventative sprays to be applied BEFORE the damage appears. There is little that can be done once the damage appears. Trees normally add more new foliage over the next few weeks and effectively "green up". Patience works wonders. Look for ash anthracnose in the Metropolitan Region where, in contrast to the rest of the state, they have received 125% of normal rainfall this spring. See map.
The other problem that ash, again green ash, suffers in the spring is late bud break. A common problem following abnormal winters ( a regular occurrence in Minnesota) this problem causes ash trees to break dormancy REALLY late. Again be patient, as the wine commercial says, sell no wine before its time, we would suggest that you declare no ash tree to be firewood before July 1st. Patience rules. One way to check on the health of your tree is to check the branches. Try scraping off a little bark on a twig. Green indicates photosynthesis, life and hope. Brown indicates a warm hearth this winter.