As you can see from the top photo my Columbine were attacked by leaf miners last year.

This Spring I added a one to two inch layer of compost around my Columbine. The bottom photo shows this year’s leaf miner free plants.

The addition of compost appears to have eliminated the appearance of leaf miners.

I don’t know how compost would deter leaf miners. Perhaps healthier plants are able to withstand leaf miner invasion? Perhaps leaf miners are attracted to weaker or weakened plants?

Predators tend to prey on the weak.