A few weeks ago, I was sent a question about fire blight – a gardener had a seriously infected hawthorn tree cut down in her yard and the arborist left the chips on the ground. She wanted to know if she should remove the chips or keep them; her second query was what types of trees she should plant in the hawthorn’s place. Fire blight is caused by a bacterium called Erwinia amylovora. It is spread by insects, birds, wind, and water, so it is likely to have traveled from another infected plant nearby.
My recommendation was to remove the chips and dispose of them at a landfill. As for the trees, fire blight affects members of the rose family, so I advised her to avoid those, or at the very least, look for cultivars within those genera that are fire blight resistant. Trees that are susceptible to fire blight include:
There are a few shrubs to avoid as well, including roses, spirea, and cotoneaster. Raspberries can also get fire blight but it is a different strain than the other plants mentioned can contract. By knowing which plants to avoid, better choices can be made about the new selection.
Janet Melrose and I have written more about fire blight – including how to ID and attempt to control and prevent it – in our book The Prairie Gardener’s Go-To for Pests and Diseases.
Do you grow any members of the rose family? Have you ever had an issue with fire blight?
Erwinia amylovora can not survive in necrotic and decomposing chips forever. We always dispose of infected material, just because of the potential for infection from relatively fresh infections. However, in my own garden, blighted material gets left out in the forest. The infections die off before they can infect anything.
Yes, that’s absolutely correct! But she was worried about using the chips right away and the potential for more immediate issues. She wouldn’t have stored the chips to allow the bacteria to die off and then used them later on. (I’m thinking she had a small urban lot).
Now you got me wondering how long it survives. I had not considered that. I either dispose of the debris or leave it to deteriorate for a long time. There is not much in between.