Florist Hydrangea Update

Healthy hydrangea in bloom in high filtered shade. Note how healthy the foliage looks.

Basically leaf spot free foliage

Foliage with leaf spot

Overall blooms September 16, on endless summer plants in sun

My number one question this time of the year regarding florist or mop-head hydrangeas is “what’s wrong with the leaves, they have spot all over them.” While I cannot be exact, it is some type of leaf spot, and usually they are growing in sun. Can you control this? The answer is yes, if a fungicide is applied before it occurs. Immunox is a good general purpose fungicide that usually does the trick if applied according to label directions about every two weeks. This time of the year; however, that is a waste of time. So you will just have to tolerate ugly leaves and enjoy their last flowering period for most of the selections. Once all of the diseased leaves have dropped from the plant, rake them up and dispose of them and the mulch that is under the plant. Replace the mulch with fresh to aid in winter protection. It is perfectly okay to wait until the weather cools in early December to reapply the mulch. All of my hydrangeas located in sun have leaf spot, but there is none to speak of on the shady plants (see photo). I have long advocated that while some species of hydrangeas love full sun, part shade is best for the florist type hydrangeas to have foliage as pretty as the flowers in our area. Also as you can see in the image above, now is a great time to cut the flowers for drying. I simply cut the flowering stems the length I want, turn the bloom upside in a warm dry place, and allow them to dry. Once dried I like to spray with hair spray, so they will last a bit longer and hold their dried color better. I have some I dried in our house for several years.

John Floyd

John Floyd has been gardening--and learning about Birmingham area gardening--for more than 30 years. In addition to his day-to-day experience, John has degrees in horticulture from Auburn and Clemson Universities and was Editor-in-Chief of Southern Living.

Leave a Reply

Your email address will not be published. Required fields are marked *