Blackfly Feastival

Posted on August 12, 2015 by davidsgardendiary

This year has been the worst I can remember for Blackfly on my climbing French beans. The Black Bean Aphid, Aphis fabae, is the culprit and nothing I do seems to reduce the infestations. I don’t spray with chemicals so every control is organic or mechanical and despite washing them off with a hosepipe and rubbing them off with my fingers, they are back in even greater numbers the next day.

The bean harvest is in full swing but really, would you eat these?! The upside, if there is one, is that I am supporting the local ladybird and hoverfly population as they and their larvae are having quite a feast themselves!

Ant Farmers?

Posted on July 16, 2013 by davidsgardendiary

Is it just me or does anybody else find ants and aphids together? I am sure the ants are not eating the aphids, they seem to be fussing over them, ‘farming’ them as you would do if you kept livestock.

It may be a sugary excretion they like or something more sinister, but it seems everywhere I have aphids, green or black, I have ants. I got really close this morning and watched an ant stroking the aphid gently as if to reassure it. It was most odd!

Or perhaps I am just making too much of it and they are deciding which one to eat!

Just found this article which seems to confirm the farming theory.

Ants and Aphids – Who Knew? (littleworldofhope.com)

Problem Corner

Posted on June 30, 2013 by davidsgardendiary

Each year I grow Lupins because they are a classic cottage garden plant. They are colourful, the bees love them and they are easy to grow. But I am getting fed up with the constant attacks of Lupin aphid.

No matter what I do (apart from insecticides which I don’t use) it returns each day, devastating the stems and flowers. The sticky residue is unsightly and the flowers are ruined. I think they’ll have to go.

The other problem is the powdery mildew which attacks the Knautia macedonica as a matter of course each year. I have always associated powdery mildew with dry soils, lack of air circulation and overcrowding but I reckon I could plant this Knautia anywhere and it would suffer. I believe it is systemic in this plant. I have seven plants in various positions and every plant has powdery mildew. It is such a shame but it too will have to go.