Troubleshooting
New York Aster 'Fellowship' problems — and how to fix them
New York Aster 'Fellowship' (Symphyotrichum novi-belgii) 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
A common problem for novi-belgii types; improve air circulation by spacing plants 60 cm apart, divide regularly, and water at the base rather than overhead.
Wilt (Verticillium)
Sudden yellowing and collapse; no cure — remove and destroy plants and avoid replanting Symphyotrichum in the same location for 3-4 years.
Slugs
Newly emerging shoots in spring are vulnerable; protect with slug pellets or barriers in cool, wet springs.
Flopping
Tall stems topple in wind and rain; install ring supports early in the season or apply a Chelsea chop in late spring to reduce height.
Clump congestion
Plants deteriorate quickly at the centre; divide annually or every other year in spring for best vigour.
Prevent new york aster 'fellowship' problems before they start
Most new york aster 'fellowship' issues are care-mismatch, not bad luck. Dial in the basics:
New York Aster 'Fellowship' problems — FAQ
Why is my new york aster 'fellowship' powdery mildew?
A common problem for novi-belgii types; improve air circulation by spacing plants 60 cm apart, divide regularly, and water at the base rather than overhead.
Why is my new york aster 'fellowship' wilt (verticillium)?
Sudden yellowing and collapse; no cure — remove and destroy plants and avoid replanting Symphyotrichum in the same location for 3-4 years.
Why is my new york aster 'fellowship' slugs?
Newly emerging shoots in spring are vulnerable; protect with slug pellets or barriers in cool, wet springs.
Why is my new york aster 'fellowship' flopping?
Tall stems topple in wind and rain; install ring supports early in the season or apply a Chelsea chop in late spring to reduce height.
Why is my new york aster 'fellowship' clump congestion?
Plants deteriorate quickly at the centre; divide annually or every other year in spring for best vigour.