Hydrangea flowers browning out

Asked August 12, 2020, 12:56 PM EDT

My Invincible Hydrangea’s is barely turning pink and turns greenish brown. Leaves seem good. What could be causing this and what I should do?

Washington County Minnesota

5 Responses

Thank you for writing. You do not say how long the blooms are lasting--individual blooms go for a couple weeks.
Excess nitrogen fertilizing causes plants to put energy into leaves. This can happen with hydrangeas when people are trying to manipulate color with lots of fertilizer.
Deadhead hydranges for more blooms! https://www.millcreekgardens.com/how-to-deadhead-hydrangeas/

Thank you they turn brown in about 2 days. I have only put miracle grow once this year so I do not think it’s over fertilizer.

What should I do? Thank you!!

Thank you for writing.
I am not finding a lot of information on this problem. Here is a sampling from reliable sources.
1. Hydrangea paniculata varieties do better in full sun but they can brown if they’ve dried out in between waterings, or if the flowers are getting hit with irrigation on a daily basis.

2. There are two things that cause hydrangea flowers to brown quickly. The first is exposure to hot sun and the second is the frequent splashing of water on the flowers. If a hydrangea is in a place where the sun is hitting the flowers from 11 AM to 3 PM that flower will brown faster than those that are in shade during that time period. Secondly, if a sprinkler system or hose is hitting the flowers frequently, this will also cause the petals to go brown. So in order to keep any hydrangea bloom in great shape for a longer period of time plant it where it will be in shade during the hottest part of the day, and water it deeply every 5 to 7 days depending on temperature, only in the morning so that the foliage and flowers dry quickly during the day. If a hydrangea is watered for a long period of time every 5 to 7 days, and the area around the plants is mulched, the plants will be able to go without more irrigation which will keep the flowers in better shape.

https://www.espoma.com/flowers/fix-it-to-nix-hydrangea-problems/

I hope this helps but if not, tell me and I will send this on to another Master Gardener.


I will look at these areas closer. Last year I had no problems with the same sun and water so it does surprise me this year.

you don’t think it’s yellow aster so you? One friend said I should ask you this.

Thanks!

Hello Steve asked me to speculate as to the cause.

My guess would be they are senescing early due to hot weather stress. I think Steve covered all the cultural reasons. They do get reflected heat off the fence and we have had some brutal days. They could also be in an area that got 5 inches of rain and they got water logged. Its is a stress too. I doubt it is aster yellows they don’t look distorted. https://fairfaxgardening.org/plant-virus/