Brown spots appearing on new blueberry plants - Ask Extension
Hello!
These spots (pictured) have appeared recently on the leaves of my blueberry bushes. They're especially plentiful on one, but are starting to a...
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Brown spots appearing on new blueberry plants #642350
Asked May 28, 2020, 11:38 AM EDT
Hello!
These spots (pictured) have appeared recently on the leaves of my blueberry bushes. They're especially plentiful on one, but are starting to appear on most of the others, as well. I planted the bushes (5 total) in early March; they're all highbush blueberries of different varieties.
I have been preparing the soil for blueberries since October-ish, including adding quite a bit of peat moss as well as rounds of acidifier. I just confirmed that the pH is now 5.5ish. I'm unable to confirm the current reading since my husband appears to have lost the gauge while "reorganizing" the garage, however. I applied a tiny bit of fertilizer a few days ago, though the first spots had already appeared on the first plant at that time. What is this? What can I do?
Thank you!
Washington County Oregon
Expert Response
It doesn't look like any of the diseases in http://pnwhandbooks.org/plantdisease/host-and-disease-descriptions?title=blueberry. I know blueberries are sensitive to nitrate-based fertilizers so I'm wondering if it's damage based on the type of fertilizer you used, but you did mention some of the spots appeared prior to the application of the fertilizer. the only other possibility is scorch, but the patterns are different http://pnwhandbooks.org/plantdisease/host-disease/blueberry-vaccinium-corymbosum-scorch. You could contact https://extension.oregonstate.edu/harec/plant-pathology-diagnostic-laboratory-services. they are more for commercial agriculture testing and not for the home owner. You could also contact the retailer from whom you purchased the plants to find out if others have had a similar problem. Most nursery stock is monitored for these types of pathogens.
You can try removing the most affected leaves but it may be worth monitoring this for several days to see if the areas on existing leaves get larger.
In general, you don't have to work that hard to acidify the soil enough to support blueberries. When I first planted them in my yard (30 years ago) I didn't do anything special and they have been doing fine for years.
You can try removing the most affected leaves but it may be worth monitoring this for several days to see if the areas on existing leaves get larger.
In general, you don't have to work that hard to acidify the soil enough to support blueberries. When I first planted them in my yard (30 years ago) I didn't do anything special and they have been doing fine for years.
