spots on swan plant
have a swan plant growing outdoors, and towards the end of summer,
as the monarchs were leaving, I noticed the leaves of the plant
were covered in black spots and were also present on the stems too.
I'm confident in labelling this a fungal infection and would like
to know more about what fungus it is and how to treat it.
am wondering if the black spots you describe are black aphids which
do look different from the common green aphid. Being on a swan plant,
they are best removed by fingers or soapy water rather than spraying,
as there may be monarch butterflies flying around on sunny days
and an insecticide spray will kill them.
If you are unsure, take
a sample into your local garden centre for positive identification
before taking action.
by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor
of Resource Management.
with permission from NZOOM Home and Garden content,
from the previous
The views expressed here are not necessarily those of the RNZIH