Ashes on my plants

Question

I live in Montana in the middle of many current wildfires. It rains ash on some days leaving my plants with a layer of ash on the flowers and leaves. Should I be hosing off my dahlias, crabapple trees, roses etc to get rid of the ash? My husband said the ash won’t harm these plants/trees.
Thank you

Answer 1

Probably no great harm to leave it on the plants short term until you get rains that will wash off the ash. But if up to me I would hose off a heavy deposit on and under leaves because it can block sunlight access and photosynthesis of sugars that nourish plant tissues, and it can block stomata that are openings for leaf moisture regulation and respiration. It may also have a drying effect.
Heavy deposits of ash can affect soil chemistry and mineral balance, sometimes good sometimes not so good. After the fires are done and the winter rain and snow has taken the ash into the soil, you may consider running a soil test in spring to analyse soil mineral content and pH (acid/alkaline balance). And correct imbalances with recommendations from a soil analyst.