Newly planted Oak Leaf Hydrangea with Spots!

Asked June 16, 2018, 9:18 PM EDT

We just bought and planted two Ruby Slipper Oak Leaf Hydrangeas and I noticed as we were planting them that there were a few black/purple spots on some of the leaves near the bottom. Is this stress on the plant being in a pot, stress from sun or is it fungal? What I have read online suggests fungal which has me concerned since it is present right when we plant them will this be something we have to deal with every year? We have been careful to water only at the base and not getting leaves wet since we have had the plants but it was a very wet spring as you know. There is a warrenty on the plants from the nursery. Would this be something that warrants returning the plants to the nursery? Or is it something that will go away once they are established? What should I be doing? Thank you!!

Montgomery County Maryland disease issues shrubs natives oak leaf hydrangea cercospora leaf spot on hydrangea oak leaf hydrangea leaf spot

4 Responses

Yes, this is a fungal leaf spot, known as cercospora, very common on hydrangeas is very wet years. It is not critical, and will be worse in wet years. You may never see it again after this year. No treatment is necessary.

ECN

Yes, this is a fungal leaf spot, known as cercospora, very common on hydrangeas is very wet years. It is not critical, and will be worse in wet years. You may never see it again after this year. No treatment is necessary.

ECN

Thank you! It was a particularly wet spring this year. Should I remove any of the infected leaves or can I leave it as is?

It's not needed, but will lessen the pathogen load in the landscape.
It really depends on the plant. If it has plenty of other leaves then yes.
If it is sparse and those leaves still have plenty of green to produce chlorophyll, leave them.

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