I have tried many times to grow asters but they alway die just as they are
starting to flower or sooner. Here's an entry from my journal for 2004:

August 26: The plants did not grow very much, but they put out a nice
display of flowers. Now, unfortunately, they have mostly succumbed to
whatever kills asters in my garden. Most plants have dried up and died.
August 29: I pulled the plants out. They were quite dried up, and I saw that
their roots systems had not developed since they were planted, but may in
fact have diminished.

I subsequently had the plants looked at at the Univ. of Manitoba and they
were diagnosed by microscope as having fusarium.

December 2: They were almost certainly killed by fusarium fungus. This
fungus resides in the soil and enters the plant through the roots. It then
spreads upwards into the whole plant, killing it. It is quite specific,
affecting (probably) only asters, and then not every variety.

I understand that fusarium is supposed to die out if no suitable host plants
are available. I have waited years between tries, and the asters die next
try. I have tried several varieties of aster, with the same result. I have
tried different end of the garden. No luck. There are no plants nearby
that I recognize as disease vectors. Asters in pots do fine until I put
them in the ground. Asters in the city parks grow fine, and the city does
not use any preventative chemicals.

How can I grow asters in my garden?