Troubleshooting
Dutch medlar problems — and how to fix them
Dutch medlar (Mespilus germanica 'Dutch') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Powdery mildew (Podosphaera clandestina)
White powdery growth on young shoots and leaves; particularly affects the large foliage of 'Dutch' in dry, warm conditions. Prune for airflow; avoid overhead irrigation. Resistant to major outbreaks under temperate UK conditions.
Brown rot (Monilinia fructigena)
Large fruits of 'Dutch' are susceptible to brown rot post-harvest or on the tree following wet autumns. Harvest before hard frosts and blet indoors; remove all rotten fruit promptly.
Aphids (various spp.)
New growth may attract aphid colonies in spring. Usually not severe on mature trees. Encourage natural predators; apply winter wash on dormant trees if populations were heavy the previous year.
Prevent dutch medlar problems before they start
Most dutch medlar issues are care-mismatch, not bad luck. Dial in the basics:
Dutch medlar problems — FAQ
Why is my dutch medlar powdery mildew (podosphaera clandestina)?
White powdery growth on young shoots and leaves; particularly affects the large foliage of 'Dutch' in dry, warm conditions. Prune for airflow; avoid overhead irrigation. Resistant to major outbreaks under temperate UK conditions.
Why is my dutch medlar brown rot (monilinia fructigena)?
Large fruits of 'Dutch' are susceptible to brown rot post-harvest or on the tree following wet autumns. Harvest before hard frosts and blet indoors; remove all rotten fruit promptly.
Why is my dutch medlar aphids (various spp.)?
New growth may attract aphid colonies in spring. Usually not severe on mature trees. Encourage natural predators; apply winter wash on dormant trees if populations were heavy the previous year.