VX writes
This is from the Crocus web site, on aphid control. I've read this a number
of times and I have finally concluded that I *really* do not understand what
it means. The first two sentences are clear enough- it's when they go on to
nettles and "a colony" (of what?) that I get lost. And then cutting back the
nettles- why? Nothing of the last two sentences seems to make sense. Maybe
I'm just having a very dense day, or possibly this is not explained as well
as it might be. Please- could anyone explain the last part to me?

Treatment
Organic - the best thing to do is encourage the predators of aphids, such as
ladybirds, lacewings and hoverflies, into your garden. This can be done by
planting nectar-rich flowering plants which attract them, such as buddleia,
calendula, sedum, stocks, sweet William and wallflowers. [That's clear
enough, but from here on I'm lost...] Get a head start on the aphids by
growing a patch of nettles with a small colony to help build up natural
predators in your garden. Cut back the nettles when aphids appear in other
parts of your garden to encourage the predators to seek them out.

I think it means - encourage a small patch of nettles with aphids to
build up the predator population, then when you have the predators, cut
down the nettles so the predators have to go and search out the aphids
on the rest of your plants.

It's the same principle as Janet B recommends - attract tits to your
aphid infested bush by hanging a fat ball in it, then the tits will
start on the aphids.

Why nettles, I don't know. I'd never thought of them as particularly
aphid prone.
--
Kay