Go Organic: Bad year for blackflyBy James Ashford
June 24, 2011
It looks like another dreadful year for blackfly.
You almost always get them on broad beans and as long as you keep on top of them they don’t cause too much of a problem.
This year they seem to be everywhere.
I’ve got them on my runner beans and even on the courgette flowers.
In small numbers they don’t do any real harm but because they breed so quickly they can become quite a problem.
Blackfly, like all aphids, feed on the plant’s sap and will eventually weaken and kill their host.
They can also spread viral diseases from plant to plant.
Conventional gardeners have no hesitation in reaching for the sprayer, and while it’s temping for organic gardeners to do the same it’s always worth finding out whether you can keep aphids under control without resorting to chemicals.
There’s no substitute for vigilance, so make time every day to have a really good look at your vegetables, especially around tender growing tips.
When you see blackfly, gently squish them with your thumb or dislodge them with a blast of water.
Aphids prefer young leaves and shoots because they can break through the softer tissue more easily. Unfortunately this is where they can do most damage.
Check the undersides of leaves lower down on the plant, where they also cluster. The leaves will often start to curl in on themselves when they’re badly affected, but taking action then is usually too late.
Blackfly will also congregate on young bean pods and in the worst case cause them to wither and die.
But while its a bad year for aphids it seems to be a good year for ladybirds – and there’s nothing ladybirds like as much as blackfly.
As with most insects, their larvae like them even more and will eat huge numbers.
I quite often move stray ladybirds to plants that are suffering aphid attack, in the hope that they’ll stay and join the feast.
Between me squishing, and the ladybirds eating, the blackfly should stay under control on my plot.