on swan plant
HAVE a swan plant that is laden with beautiful monarch caterpillars.
However, it is also covered with aphids. They are bright orange
and are on everything. I certainly don't want to use a spray that
will harm the caterpillers, but the aphids are taking over and the
poor plant looks a little sad. Do you have any handy hints?
sounds like you have a nice healthy colony of oleander aphids. I
wouldn't worry about it too much as the monarch caterpillars will
do much more damage to the plant than the aphids, yet the plant
will probably still survive. A reasonably large swan plant can usually
put up with having its foliage completely stripped off by monarch
caterpillars. Once the larvae stop feeding and pupate, the swan
plant will most likely produce more leaves and start growing away
again, despite the aphids.
Any of the sprays you
can get from garden centres to dispose of the aphids would have
a detrimental effect on the caterpillars, so perhaps the best and
easiest way to knock the population back is to rub them off by hand.
Wear gloves if you don't want aphid juice all over your fingers.
Once the monarchs have gone you could spray for the aphids, if you
feel the need.
Gardener, Issue 195, 2006, Page 29
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.