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ucancallmeal

Hydrangea - Fungus?

5 years ago
last modified: 5 years ago

Hello Fellow Gardeners,

I'm worried about this one bed that has panicle hyd. and some astilbe, both of whom have healthy looking leaves but look impacted by something.

It's a raised bed with fertile soil made for planting beds but not the bagged stuff.

This is their 3rd year in the ground. First year in the groudn everything bloomed. Last year only one hyd. had blooms and they looked weak. The Astilbe never flowered but the stems shot up like their supposed to. The flower areas didn't open and remained brownish. All plants have tripled in size.

This year all spring all the plants have looked great. Now I see some whiteness at several of the main joints (hydrangea first pic) where stems shoot off. The Panicles are not blooming yet and Astilbe (2nd pic) look like they are going to have the brown stems without flowers again. BUt the leaves look healthy.

My guess is not enough sun. They get dappled sun all day that moves over the bed. Rain is not an issue this spring here in NC zone 6-7.

SHoudl I try a fungicide?

Thanks for taking a look.

Al







Comments (19)

  • 5 years ago
    last modified: 5 years ago

    Hello, Al. The whiteness may be scale, Cottony Maple Scale or Mealybugs (a cousin of scale). The other hydrangea leaf damage in picture 3 could be a pest or weather damage but to confirm, you need to monitor the foliage during the day and evening to tell what the pest might be. Look under the leaves, in the stems, under the soil and rocks.

    In my area (Texas), Astilbe thrive in moist soil that drains well and where it gets morning-only partial sun. Make sure you water them regularly and give them shade in the afternoon. Use mulch to keep the soil moist but avoid keeping them in soggy soil.

    Not getting blooms: Make sure you are not using fertilizers that promote growth above everything else, like some Miracle Gro formulations that are high in nitrogen. A single application in Spring of a NPK 10-10-10 fertilizer would be fine with the hydrangea and the astilbe for the whole year if your soil has no nutrition deficiencies. You can also use liquid seaweed, liquid fish and coffee grounds during the rest of the growing season but stop fertilizing three months before your average date of first frost for your area:

    https://www.plantmaps.com/interactive-north-carolina-first-frost-date-map.php

    UcancallmeAl, Zone 7, NC thanked luis_pr
  • 5 years ago

    Hi Luis,

    I found 3 beetles on one of the hydrangeas and removed them. The hyd. are starting to get their flower buds.


    I'd say the bed gets dappled sun all day. Sounds like from you wrote, that may not be enough for the Astilbe. The whiteness is showing up at the joints on the main stem but the leaves in general look good. Especially on the astilbe. There is no whiteness on them. Just like last year the flower spikes on the Astilbe are staying brown. I probobaly need to do a PH test.


    I haven't used any fertilizers just home grown mulch and purchased wood chips from Home D. We've definitely had enough rain this year.


    Can you recommend a anti fungal safe for all plants? I'm getting holes in my Coleus, Witch Hazel and a few others.


    Thanks per usual Luis.

    Al

  • 5 years ago
    last modified: 5 years ago

    Fungicides are tricky and should be purchased when made with an active ingredient that is known to address the fungal infection that you are dealing with. Bonide produces one that is ready to be used/sprayed on leaves against cercospora leaf spot; its active ingredient is chlorothalonil but any brand whose active ingredient is chlorothalonil will work well against that disease. For powdery mildew there are many others (read the label and it should say for what type of diseases you can use the product) but I always use a 40% milk + 60% water spray solution.

  • 5 years ago

    I’ll take some better pics and upLoad.

  • 5 years ago

    IME Astilbe like both more shade and more moisture than the panicled hhydrangeas. your astilbe may be unhappy because of that.

    Like GG 48, I don’t see any sign of fungus, just bugs.

    UcancallmeAl, Zone 7, NC thanked NHBabs z4b-5a NH
  • 5 years ago

    Here are some pics. The distant one shows the average amoutn of sun the area gets. The white scale is only on a few places on 2 of the hyd. The Astilbe are showing some color on the blooms so maybe this year is ok. It looks like I'm going to get some blooms this year. Found no beetles today.





  • 5 years ago
    last modified: 5 years ago

    Thanks for the new pictures. Pictures 2 and 4 show indications of some pest causing leaf damage or virus (sorry, but the leaf was too far away to tell either way) but to confirm insects, you need to catch it/them and identify them before you can decide how to control it. Discard the leaves that concern you and observe if there is a repetition of symptoms or not.

    If the white stuff in picture 3 moves when disturbed, it is probably mealybugs or scale. You can also cut that part off and take it to a local nursery in a sealed, transparent plastic bag for identification.

    Picture 4 needs to be monitored; top left leaf especially... for possible virus but... there is a sun reflection that does not let me see the leaf close and personal. The leaf immediately below has a sun reflection that is fuzzy and unclear. Something bright may be there, in between the first and second major veins of the left side of the leaf but it is unclear if it is just a sun reflection. You can cut the leaves if they bother you much and then monitor the plant for repetition of symptoms.

    Note regarding the curling: there are also some insects that cause leaf curling (spider mites, hydrangea leaf curler, etc.) as well as some chemicals in fungicides/insecticides. "Chemicals" may be ones that you have used recently or that a neighbor used and wind drift blew them towards the hydrangea.

  • 5 years ago

    Hi All,

    I took another couple of pics. Found 1, just one, beetle on one of the hyd. Since there is damage on all 3 plants but not the Astilbe, I'm guessing it's not one beetle. The white scale I'm seeing is on some of my other plants; climbing hyd. and confed jasmine. I don't see any bugs on leaf underside only small black specs but not a lot of specs. Overall, the hyd. look like they're going to bloom. Buds are forming.




  • 5 years ago

    The nursery confirmed something similar to mealy bug and sold me something to treat it with. Thanks everyone.

  • 5 years ago

    They are very common in May-June in some parts of the country. Keep that "something" handy in case if it re-occurs in future years.

  • 5 years ago

    Got a pic of the beetle and some other white bug which I guess is the reason for the white residue on the branches. My sprayer had roundup in it. Ok to wash out and use to apply fungicide? I assume that no beetle species is beneficial.

  • 5 years ago

    That beetle is same kind that was on hydrangeas.

  • 5 years ago

    If it is green and brown, it probably is a Japanese Beetle.

    UcancallmeAl, Zone 7, NC thanked luis_pr
  • 5 years ago

    Yes the first photo is definitely a Japanese beetle. Go out first thing in the morning and/or just before dark with a can of soapy water. Hold the can under the beetles and knock them in. You can also spread milky spore disease on your lawn according to direction. It will infect the grub stage of Japanese beetle in your lawn and prevent them from maturing into the adults. This has to be timed right so read the directions, but in your zone it shouldn’t need repeating in fututre years. you will likely still get some flying in from neighboring yards, so you will still want to do the can of soapy water as needed.

    UcancallmeAl, Zone 7, NC thanked NHBabs z4b-5a NH
  • 5 years ago

    Checked this morning and no beetles but will ask the lawn people if we are protected from beetles. Prob not. Will research the milky spore disease. So far I've only removed 5 beetles in the last few weeks.


    Didn't see any other pests. Lots of insects buzz around the astilbe late in the day, diff types of bees and others. They are blooming with color!


    I followed the direction on the fungicide and treated jsut one hyd to see what happens.

    All the hyd blooms are forming pretty quickly.


    Keeping fingers crossed and thanks everyone.

    Al

  • 5 years ago
    last modified: 5 years ago

    Probably not. These are hungry troublemakers that eat leaves and flowers and the grubs need to be dealt with too:

    https://www.thespruce.com/controlling-adult-japanese-beetles-1402495

  • 5 years ago
    last modified: 5 years ago

    A bit confused. If it was identified as mealy bugs, then hopefully it was an insecticide used not a fungicide.

    Safest to have separate herbicide and pesticide sprayers.

    All in all in those pictures, I don't see anything overly concerning. The leaf distortion look more like insect feeding damage I get most years. And just because a bug in on a plant doesn't mean it's doing anything.

  • 5 years ago

    Yes, I wrote imprecisely because I couldn’t remember exactly. I’m thinking it’s not too serious so far as well now that I’ve had input. Thanks for following up. I only tested on one plant to see results and will report back.

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