flowers are spotted

[Margo]

This year our All Summer Beauty hydrangeas had brown spots on the flower petals. We had a very dry summer. Could that be the reason? Or perhaps I'm not fertilizing properly. Suggestions ? Zone 5.

[Grey]

I'm guessing either a fungus, or sun scalding. Or maybe blight.

With a fungus, it should also affect the leaves, however. A treatment of neem oil should help this.

If the plant got wet and the sun was very hot, the remaining water can burn the petals and you will get smooth, almost round, brown spots.

In blight, petals turn brown and fall. Spots may form on the leaves, especially where faded petals have fallen, and flower buds may be killed before opening. This can be caused by the plants being too close together, not permitting enough air circulation. I would also not put any cuttings/trimmings in the compost bin - throw them out.

[The Helpful Gardener]

I'm with you Grey; one of these is definitely the culprit. I'm leaning towards scald, as fungii usually leave that purply-red color as well, and Margo just said brown...

Scott

[Margo]

You know. The petals never fell off. Which make me think sun/heat etc. However, if it is a fungus or blight will it automatically return next spring/summer? Neem oil? Is this somethiong found at garden centers?

[Margo]

P.S. I forgot to mention. The leaves remained healthy and green.

[The Helpful Gardener]

No purply color to the spots? Then I doubt it's fungal; skip the neem oil and just make sure to water at the base, not wetting the flowers, and keep the air circulation moving in that area by not allowing things to get overgrown and dense. That should do it...

HG

[Margo]

Thanks. I'll do just that.

[The Helpful Gardener]

Welcome...