HAVE a dwarf kowhai, 'Dragons Gold', which was devastated by caterpillars
in summer. It was in a tub, but I have since planted it in the garden
and it seems to have recovered enough to produce a covering of leaves,
but only about half a dozen flowers. Should I give it a feed? If
so, is a slow-release fertiliser the best? Also, what is the best
spray to use to prevent another caterpillar attack? I have used
neem oil in the past.
don't generally require much in the way of feeding, so in reasonable
garden soil a general fertiliser, whether slow-release or not, should
be fine. Don't be tempted to apply lots of fertiliser, as you'll
probably only encourage lush growth at the expense of flowers.
What's likely to also
have a very beneficial effect is applying a good layer of mulch
to conserve soil moisture over summer, as well as an occasional
watering in dry periods.
Neem oil should help
control kowhai moth caterpillars, but you'll need to spray at the
right time. Check your plants regularly through summer and spray
as soon as you spot the first few caterpillars - while they're still
small and haven't had time to do much damage. You need to be vigilant,
as they grow quickly and can sometimes strip a small tree in just
a few days! One or two timely sprays will often be enough to control
Other products you could
use include Success Naturalyte, one of the many pyrethrum-based
products such as Garlic & Pyrethrum, and Derris Dust.
Gardener, Issue 178, 2005, Page 32
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.