I harvested a 2-leaf stage new seedling this summer from under a Bloodgood JM: appears to be Acer palmatum, or Acer palmatum ‘Atropurpurpeum’ seedling. Managed reasonably well in the wet/hot St Louis summer, but I just noted yellowing patches on some leaves (one possible cause is morning sprinkler exposure which I stopped) - - took a photo and higher magnification shows minute black spots - suspect fungal, potentially early lesions of Anthracnose, Phyllosticta, or Tar Spot - will see what develops. I know Neem oil may injure maples and this is a young unhardened seedling, but opted to spray with dilute Neem concentrate 1Tbsp per gallon and keep in shade away from sprinklers. Any ideas re the cause - am I on the right track? Neem seems a general coverage if the seedling will tolerate - I may consider change to pyrethrin/sulfur spray or a copper fungicide spray if Neem adversely affects the leaves in the days ahead or if the involved leaves worsen. Just attempting the challenge of raising a maple bonsai from natural seedling harvest. Should I remove involved leaves, the upper, newer leaves have no lesions yet - no debris on the soil surface
