Prairie gardening tip: What to plant in place of a tree infected with fire blight.

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:

Apples

Crabapples

Pears

Mountain ash

Hawthorns

Saskatoons (serviceberries)

Plums

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?

Mountain ash.

During a recent walk in the neighbourhood, I couldn’t help but admire the mountain ash trees, their clusters of bright red berries dusted with fine powdery snow.  They are certainly decked out for the festive season!   The birds weren’t hungry enough this fall to pick the trees clean – judging by the way they went after the Schubert chokecherries in the driveway, mountain ash do not appear to be the current rage in bird food.  Mountain ash trees (also known as “rowan” trees) are common ornamentals in western Canada due to their excellent cold tolerance and general lack of pickiness regarding soil type – plus, with their gorgeous berries and interesting foliage, they have that whole aesthetic thing going on.   Many of the mountain ash trees we have in Alberta are Sorbus americana, with fruit that is so bitter that it is nearly unpalatable to humans, but in Europe, the fruit of Sorbus aucuparia, particularly the cultivar ‘Edulis’, is actually fairly widely used as a condiment.  Fresh-picked, the berries (botanically called “pomes”) are still hard on the tastebuds, but apparently they make an excellent, albeit seriously tart, jelly that is often used with meat and poultry dishes.  If mixed with other berries or fruit, such as apples, blueberries, or blackberries, mountain ash berries can be used to make a sweet jam spread.  And, apparently, in centuries gone by, an alcoholic liquor called diodgriafel – a Welsh specialty – was made from fermented mountain ash berries.  (I don’t know whether or not that particular beverage is still being produced – a call out to anyone who might know, or better yet, have tasted it!).  At any rate, diodgriafel was certainly a libation with a serious health benefit:  mountain ash berries are chock-ful of vitamin C, and were used to ward off scurvy before other vitamin C-rich fruits such as lemons became more accessible to everyone.

Bottom’s up, and happy holidays!

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en.wikipedia.org/wiki/Sorbus_aucuparia

sacredearth.com/ethnobotany/foraging/rowan.php

countrylovers.co.uk/wfs/wfsberries.htm