Why Did My Hydrangea Flowers Turn Brown?

Why Did My Hydrangea Flowers Turn Brown?

You patiently waited for six months while the Hydrangeas were bare sticks, you actually had flowers appear despite the hard winter or bad pruning, but by the first week in August they were brown!  Sometimes life is SO unfair. So why did your flowers turn brown when your neighbor’s are still in bloom? Here’s what causes this to happen:

1. Hydrangeas growing in full sun. Although given enough water Hydrangeas will thrive in full sun, the flowers will become brown by the end of July when they are sunshine during the mid-day when those rays are strongest. Blue mophead and lacecap hydrangea flowers last longest when they are shielded from sun from about 10 AM to 3 PM.

2. Shallow or inconsistent watering. We have to take the “hydra” part of their name seriously. Those large leaves and big flowers lose lots of water, especially in hot weather. If a hydrangea is being watered every other day for twenty or thirty minutes (sadly, standard automatic irrigation settings) the plant is likely to wilt in hot weather. Once the flowers wilt a few times they will turn brown. Similarly, if you water deeply but then skip a week or two, the flowers will droop and brown in between drenchings.

3. Fertilizer or Aluminum Sulfate burn. If a plant (any plant…it doesn’t have to be a hydrangea) is given too much synthetic fertilizer it will cause fertilizer burn. If a plant is given a strong does of fertilizer when it’s dry, you’ll also see browning flowers and leaf edges. And if a Hydrangea is given a strong dose of Aluminum Sulfate (to turn the flowers blue) when it’s dry, that also can cause brown blooms. Never fertilize a thirsty plant. Always use aluminum sulfate at the rate recommended and make sure the plant is well hydrated first.

So now you know. What turned YOUR hydrangea flowers brown?
So now you know. What turned YOUR hydrangea flowers brown?
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16 Comments

  1. judywass on August 18, 2016 at 10:01 am

    Thanks for all the info on hydrangeas.
    Miss the beauty of the shades of blue as summer wanes
    Alas! no Hydrangea wreaths this year……
    Judy
    Should we do a Rain Dance?
    Judy

    • CLFornari on August 18, 2016 at 10:29 am

      All dances for rain and a mild winter appreciated!

  2. Karen on August 18, 2016 at 8:49 pm

    Very appreciative for the info on hydrangeas. Miss all the beautiful blue in my gardens and have been trying to figure this out! Thank you!!

  3. Taunte Lala on July 21, 2018 at 7:21 pm

    The browning on the petals is worse on the paler varieties like white and pink.

    • CLFornari on July 21, 2018 at 7:58 pm

      Taunte,
      This is typical of all flowers – it’s not that the browning is worse on white and light pink varieties, it’s that it is noticeable earlier. This is the reason that some people shy from white flowers, because the brown shows up much more quickly.

  4. Frances S. Parks on August 23, 2018 at 11:20 am

    Again this year I have lots of leaves on my Endless Summers but few flowers. Some without any flowers at all and others with smaller flower heads than usual. Anything I can do at this point or next spring? Thanks

    • CLFornari on August 23, 2018 at 1:34 pm

      If you’re on the Cape, Frances, know that the warm warm fall followed by a hard freeze in early December zapped many hydrangea buds. There are pockets on the Cape where people still had good hydrangea bloom, but for most people it was spotty. What can you do? First of all, never cut them back – the only pruning you should do is to remove dead wood in late May. Never “neaten them up” in the fall or winter. Then hope for a mild winter! For more information see this article: https://www.gardenlady.com/read-articles/why-doesnt-my-endless-summer-hydrangea-bloom/

  5. cat logan on August 23, 2018 at 12:06 pm

    My hydrangea leaves are still very green but are beginning to pucker. They look like something is inside the veins. Time for insecticide?

  6. Jane on August 23, 2018 at 4:55 pm

    Thanks for the info on hydrangeas. Mine have also turned brown, which wilted a lot during the hot summer. I might have put too much aluminum sulphate on in the fall and spring.

    • CLFornari on August 23, 2018 at 5:40 pm

      Jane,
      Many people go overboard with the Aluminum…but on the Cape we have naturally acidic soil and our hydrangeas will usually be blue if we simply fertilize with Holly-tone.

  7. Kelly on September 8, 2019 at 4:59 pm

    Ours were brown for most of the summer sadly. We watered them twice a day all summer through our irrigation system. Was that too much water maybe?

    • CLFornari on September 11, 2019 at 3:43 pm

      If your hydrangeas are planted in full sun that is the problem. If you’re watering twice a day my guess is that you’re hand watering which is never enough. Use a soaker hose or sprinkler and water for a couple of hours every three to five days depending on the temperature. If they are in full sun you might want to move them to morning sun and afternoon shade in that blue hydrangeas in full sun always brown quickly.

  8. gene smith on July 7, 2023 at 11:50 am

    i live in missouri (s.w). will my now browned flowers ever turn back white? the whole plant isn’t dead is it?

    • C.L. Fornari on July 10, 2023 at 5:51 pm

      Once a flower turns brown it will not turn back to the fresh color again. Snip it off.

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