"Tumbleweed" wrote in
:

Its often used an excuse that you must have been spraying or someone
nearby must be spraying, if you have got lots of pests. It aint so.
The simple fact is that generally pests like greenfly can vastly
outbreed their predators (e xcept in artificial circmstances such as
the parasitic wasps in greenhouses) and that their numbers are
controlled either through seasonal factors (for example winter) or
shortage of food. Pretending that nature will strike a balance which
includes mopping up all the greenfly and caterpillars on your plants
is just that, a pretence.

I'm not pretending. Nor did I say that 'nature would strike a balance'.

I still think, (having tried it), that gardening 'organically' in a
small garden surrounded by other non-'organic' gardeners is a bit
pointless. Your stuff will be affected by other people's approach: you
can't pretend you are on a desert island when the council is squirting
weedkiller through your fence.

If everyone else in the area has the same problem, it may (or may not)
not be caused by the use of pesticides, and it might well not go away if
they weren't used.

I don't know of any detailed tests. Do you? So far, we seem to be
working with anecdotal evidence on both sides of the discussion.

I genuinely don't have greenfly problems here. If they aren't being
controlled by predators, what other factors would you suggest? It could
be the soil or climate, but I'm not clear how those interact with
greenfly populations.

The difference in bird and insect life is one of the more obvious
things. I still sometimes get aphid problems on houseplants: putting
them outside usually clears them.

Victoria
--
gardening on a north-facing hill
in South-East Cornwall
--