Lisa Dettloff
Lisa Dettloff
  • Hometalker
  • Grosse Pointe, MI
Asked on Aug 7, 2013

What are these black spots on my hydrangeas?

Felicity WoodruffeJean McKayGre209756
+13

Answered

What are these black spots on my hydrangeas? How can I make them bloom big flowers? They were do full and pretty when I bought them
Flowerless hydrangeas :-(
Flowerless hydrangeas :-(
12 answers
  • If they are not blooming, how long have they been in the ground? and were they bought in a garden center or in the floral dept. Most likely the black spot is from too much humidity and/or moisture so do not panic. Remove any leaves that are diseased and look bad and dispose of them. Hydrangeas, along with many other plants, do not like their foliage to be wet. I would get a good fungicide because powdery mildew sometimes goes along with black spot. Hydrangeas will not bloom if they freeze back to hard in the winters. You live in MI which can get very cold and many hydrangeas do not like to be frozen. You may want to think about covering your hydrangeas or creating a structure to keep the plants warmer in the coldest months. Also does it get any sun? It may need to have a bit more sun too~not full sun but not heavy, dense shade. Or if it is in full sun, may need a bit more shade. So for this winter I would prepare to cover the hydrangea because they do not like cold.

  • Lisa Dettloff
    on Aug 8, 2013

    Hi Renée! I bought them at an Eastern market. They were so full and beautiful when I planted them two tyears ago

    • @Lisa Dettloff see how much sun they get today. In your neck of the woods they would love morning sun or even a couple hours of after noon sun. It is important that you protect them over the winter. The severe winter freezes the plant and it will not bloom. Simple as taking chicken wire around 4 or more stakes (depending upon how large the hydrangea is) and carefully filling the "wall" with straw. Whatever woody branches are left after the hydrangea dies down be careful not to damage them when filling it up.

  • Lisa Dettloff
    on Aug 8, 2013

    Thanks for the tip Renee. I have them in partial shade and sun...they tend to droop when the sun hits them and then come back in the evening...I will give them a trimming... appriciate the tip... Thanks again, Lisa

    • @Lisa Dettloff only trim the badly diseased leaves or dead branches. Hydrangeas, in my experience, do not like to be trimmed. they like to be left free to grow. LOL

  • Lisa Dettloff
    on Aug 8, 2013

    Thank you @The Garden Frog with C Renee ...I will do that...you may get tired of hearing from me for other gardening questions :-) Well gotta get clipping...

  • Lisa, if they were bought at a floral market verses a nursery it's quite possible they have very few roots growing in the pot to support what is on top. Plants produced for floral shops are all about high fertilization for showy top growth only. If you don't have the best luck with this plant in the ground it's probably got very little to do with what you have or haven't done.

  • Diana
    on Aug 9, 2013

    Lisa I had this problem and no bug spray worked. I read that hydrangeas like coffee grounds and egg shells crushed up and it would keep some ? bugs off. So I scattered grounds around the plant (2-3" from the plant) and put the crushed shells right at the base all the way around. In a week those spots were gone. When I noticed them coming back I added more coffee grounds it worked.

  • Lisa Dettloff
    on Aug 9, 2013

    Thanks for the tip Diane! Will try anything easy

  • Diana
    on Aug 9, 2013

    It will work if you have anymore questions about this problem just ask.

  • Gre209756
    on Aug 11, 2013

    Hi Lisa D. My new hubby likes coffee every morning, he brews and then I take and save the used coffee grounds, I used to use regular coffee but he uses the Decaf Folgers now, SO anyway, I have the BIGGEST blooms there has ever been, these hydrangeas are beautiful, the coffee ground I let sit in a plastic bowl and the air drys them out, then after about 5 days worth of grounds I would take and put around the outer circumference of the 2 plants I have, then the 2nd week I took and sprinkled the grounds all over the plants and put hose on light spinkle...no bugs no spots...I will have to take a pic and figure how to get it uploaded on here for you to see, the blooms are blue and a very pretty shade of purple...

    • Fran Barrett
      on Aug 27, 2013

      @ So THAT'S how to do it! I have these wet coffee grounds and hate handling them, plus they don't sprinkle very well. Do other plants like them or just the hydrangeas?

  • Gre209756
    on Aug 11, 2013

    I haven't put the egg shell water on the hydrangeas, and mine are in the shade most of the day after the morning sun, but I use the eggshell water on the impatiens, in the hanging baskets and they love it!

  • Jean McKay
    on Aug 18, 2013

    @Lisa Dettloff , I bought a sickly looking one at the nursery not many weeks ago. It was covered in brown spots, I repotted it immediately in a larger pot, then in my research I read that they do not like to be watered from above which is typical in some greenhouses and stores. since I quit watering from above and moved it into shade/sun it is coming back a day at a time. Good luck

  • Felicity Woodruffe
    on Jan 8, 2014

    I found one thrown in the trash at a cemetry i was walking through so i picked it out took it home removed yellow and brown leaves repotted it and left it in the green house til next spring.When I went to check on it there was new growth buds lots of healthy leaves it didnt flower this time but im hoping it will this year,Please I too would like to know about egg shells i usually add them to compost but am keen to hear of other uses if someone would be kind enough to elaborate thanks

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