Are yellow leaves on your oak trees a sign of trouble?

The leaves on many northern Illinois oak trees are not as vibrantly green as they normally would be at this time of year. Two late frosts are the likely cause of yellowing leaves on some oaks. (The Times)

The leaves on many northern Illinois oak trees are not as vibrantly green as they normally would be at this time of year. Two late frosts are the likely cause of yellowing leaves on some oaks. (The Times)

(The Times)

(The Times)

(The Times)