Western redcedar is an economically important tree species suffering from fungal diseases that cause wood decay and significant financial losses. Researchers developed controlled methods to test how resistant young redcedar trees are to eight different decay fungi, finding that some fungi are much more damaging than others. Importantly, they discovered that some infections remain hidden without visible symptoms but still harm tree growth, and these hidden infections can be detected using advanced DNA-based methods. This research will help forest managers and breeders develop redcedar varieties with better disease resistance.