When Bad Things Happen to Good Hydrangeas and How to Save Them

Limelight Hydrangeas #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

Happy Monday!

 Limelight Hydrangeas are just starting to bloom here in North Carolina,

the highlight of our mid-summer garden!

Limelight Hydrangeas by The Potting Shed #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

If you’re not familiar with Limelight Hydrangeas, they’re a panicle hydrangea

with an overall height and spread of 6 to 8 feet.

Limelight Hydrangeas #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

The large flower heads open as lime green in color, transitioning to creamy white

and grow 6 to 12 inches long!

Unlike other hydrangea varieties, they’re drought tolerant, thriving in full sun.

Limelight Hydrangeas #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

They bloom mid-summer, with the large white blooms offering an illusion of ‘cool’

in the garden on hot summer days and

when everything else is in the garden is looking tired and spent. . .

like I do in lugging my hose around in 90+ degree temps. ;)

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Limelight Hydrangeas #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

Like all panicle hydrangeas, Limelight Hydrangeas bloom on new wood.

Pruning Limelight Hydrangeas in early spring #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

Because of their size, they get a heavy pruning in winter or early spring,

cutting the canes back 3 – 4 feet.

Lakeside Table and ‘Pitcher Perfect’ Limelight Hydrangeas #summer #tablescape #lake #hydrangeas ©homeiswheretheboatis.net

Limelight Hydrangeas make ‘pitcher perfect’ blooms,

no flower arranging skills required,

just cut and place in the pitcher or vase of your choice.

Transitioning from Summer into Fall Table with Limelight Hydrangeas #tablescape #lake #summertofall #hydrangeas #alfresco ©homeiswheretheboatis.net

 {  Transitional Summer into Fall Table with Limelight Hydrangeas  }

They make great dried flowers, acquiring a greenish hue,

then deepening to a burnished-bronze in late fall.

The natural beauty of fall and DIY foraged arrangement of late season hydrangeas, foliage and seed pods. #hydrangeas #diy #arrangement #fall #garden #flowers ©homeiswheretheboatis.net

  {  DIY Foraged Autumn Harvest Arrangement  }

Hello October: A Fall Harvest on the Potting Bench #fall #hydrangeas #autumn #pumpkin #harvest #mums #indiancorn #leaves #wateringcans ©homeiswheretheboatis.net

 {  A Fall Harvest on the Potting Bench  }

We planted five Limelight Hydrangeas around The Potting Shed eight years ago.

I noticed last summer that one shrub in particular on the field side of my shed

was not as robust as the others, and the blooms looked stunted.

How to deal with cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

On a closer inspection, I discovered why. . .

 EEEEKKKK . . .cane borers!

How to deal with cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

‘Cane borer’ is a general term for a large variety of wood boring beetles,

that emerge from April to July, depending your gardening zone.

Some bore into the cane to lay eggs, while others bore in as larvae to feed.

I could never find a wood borer that that was specifically labeled ‘hydrangea cane borer,’

but after some googling and reading on NC State Extension’s website,

I learned there five groups of wood boring beetles

that infest trees and shrubs in North Carolina:

roundheaded wood borers, flatheaded wood borers, weevil grubs, ambrosia beetles and bark beetles;

the most common wood borers being the roundheaded and flatheaded variety.

Signs and symptoms of cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Cane or wood borers lay eggs that bore into the end of branches of certain shrubs and trees.

Signs of cane borers are hollowed out branches, drooping and yellowing leaves,

stunted growth, and a sawdust-type material that results from boring.

As the larvae are inside the canes, insecticides are not an option to eradicate them.

How to deal with cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

The larvae grow by feeding on the pith of the stems and branches, causing stunted growth,

drooping and yellowing leaves, and ultimately death of the branches by

blocking xylem vessels and interfering with the transport of essential nutrients.

Signs and symptoms of cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

 Larvae can overwinter in the hollowed stems, emerging in the spring as adults.

Signs and symptoms of cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

As Limelight Hydrangeas bloom on new wood, there are an abundance of freshly cut wood stems

  providing borers easy access to fresh pith.

Signs and symptoms of cane borer damage on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

To save your hydrangeas and prevent further damage, cut the affected canes,

pruning back the branch until you see healthy wood.

It feels painful, especially when your hydrangea is just putting out new growth,

but necessary for the health of your shrub and future blooms.

Cut canes of hydrangea damaged by cane borers until you see healthy wood #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Burn or bag your cut stems to get rid of any potential larvae to dispose of them;

don’t compost them.

Cutting canes of hydrangea back damaged by cane borers #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Look at that poor damaged pith . . . :(

We cut the branches until we reached healthy wood, continuing to cut out the damaged pith

and cutting the shrub almost to the ground.

We sealed the freshly cut stems (details below on sealing)

along with few other affected stems found on neighboring hydrangeas.

New healthy growth of Limelight Hydrangeas after pruning out cane borer damage #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

With a little fertilizer and six weeks later, we had new healthy growth on the pruned hydrangea.

With some diligence and watching for signs for borers next spring,

we should have have healthy shrub and blooms again.

Evidence of cane borers on hydrangeas #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

I noticed some evidence of cane borer damaged on some Endless Summer Hydrangeas nearby too.

I read online to seal your fresh cuts with wood glue as a deterrent to prevent beetles

boring into the freshly cut pith of the branches.

Water resistant wood glue to seal hydrangea stems from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

You’ll want to use a water resistant wood glue that

won’t wash away with the rain.

Water resistant wood glue to seal hydrangea stems from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Apply the wood glue to your freshly cut branch on a day when rain showers aren’t imminent.

It will take the glue an hour or so to dry depending the heat and humidity.

I found it easier to apply by removing the cap and dipping a paint brush into the bottle,

rather than squeezing the glue directly from the bottle. 

How to seal hydrangea stems to protect from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Growth will emerge on the sides of the cut branch,

not top of the branch, so the glue won’t prohibit new growth.

Use nail polish to protect hydrangea stems from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Option 2: If you don’t have wood glue, use nail polish to seal your cut,

which is waterproof and will dry in 15 minutes on a hot day.

I picked up some neutral nail polish from Dollar Tree to blend with the wood stems.

Use nail polish to protect hydrangea stems from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

It seems like a daunting task if you’re pruning hundreds of hydrangea canes,

but doable if you have just a few to seal as a preventive measure

to keep borers away from the tempting open wood of your stems.

How to protect hydrangea stems from wood boring beetles #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

I’m checking my hydrangeas daily for any news signs of borers.

Limelight Hydrangeas #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

Option 3: I just ordered some Pruning Sealer with Brush Top Applicator,

to have on hand, which should be a little less tedious to apply if the borers return.

New healthy growth of Limelight Hydrangeas after pruning out cane borer damage #summer #hydrangeas #garden #flowers ©homeiswheretheboatis.net

Keep Calm and Garden On!

Keep Calm and Garden On DIY Hand Stamped Copper Garden Markers #garden #spring #DIY ©homeiswheretheboatis.net

  {  DIY Hand Stamped Garden Markers  }

How to protect hydrangeas from wood boring beetles and cane borer damage #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

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When Bad Things Happen to Good Hydrangeas and How to Save Them #summer #garden #hydrangeas #flowers ©homeiswheretheboatis.net

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  32 comments for “When Bad Things Happen to Good Hydrangeas and How to Save Them

  1. Pam
    July 10, 2023 at 6:59 am

    Good morning, Mary. Oh my, I have never heard of cane borers. Yikes!! Your research gave you remedies that hopefully will keep your limelights healthy. I must share your post with my head gardener. Now that I am aware of another beetle, I will be observing any signs. Japanese beetles are getting on my last nerve. It seems they are everywhere. Gardening offers many challenges, it seems there always new ones. Happy Monday💛

  2. Rita C.
    July 10, 2023 at 7:02 am

    This is exactly what happened to the established oak leaf hydrangea in my new-to-me garden last year, and then also to one of my Itoh peonies! I also did exactly as you did – wood glue – after cutting out the stems of the peony. My oak leafs were overgrown and looked awful with the damage, so they got pulled. This year, after trimming my flower pods on peonies, I used the wood glue as a preventative measure.

    Another good share, Mary. I’ve used nail polish on trimmed roses before, another good measure.

  3. Pamela Meyers Arbour
    July 10, 2023 at 7:04 am

    I don’t have hydrangeas but that was a very helpful and informative post. Thank you.

    • Michael THOMPSON
      July 15, 2023 at 9:59 pm


  4. Cindi
    July 10, 2023 at 7:18 am

    This is my first year with lime hydrangeas..two small ones and a normal size one ( I am sure they had better names than small and normal but…). The information is quite helpful and I will be inspecting them soon. Are you rushing summer with your autumn pictures 🤣… my pool is just about warm enough to get in ( I like the water temp 85 plus…so I want summer to stay around) yes my hubby thinks I am crazy but at 68 I have earned the right to do things my way!😀. Thank you for the beautiful pictures and helpful information. Peace.

  5. Peggy Ott
    July 10, 2023 at 7:26 am

    GM Mary! Great post. Just did some of that pruning this past Spring on my Blue Hydrangea my son got for a Mother’s Day gift 8 years ago. It is doing well as of now. A very good read. I have several variety of Hydrangeas, with one like the Limelight, but it changes from cream to pink to red cones. I cut it back a lot very early Spring when there was still snow on ground, it is looking good as well. It needed serious pruning to get back into shape. Good read and as usual, very beautiful and useful pics and tips. Thanks! Have a beautiful day in the garden!

    • Clara
      July 10, 2023 at 8:01 am

      Oh, Mary, I’m sorry to hear you had cane borers in your hydrangeas. I didn’t know they had such issues. I’m so happy you were able to eradicate them. Hopefully, your hydrangea will flourish now. Thanks for the instructions on how to deal with them. Happy Monday! Clara❤️

    • Laura
      July 31, 2023 at 8:20 am

      I believe this one is called a strawberry sundae hydrangea 😊

  6. Susie
    July 10, 2023 at 8:18 am

    Thank you for this!!! I am on the way out to check the hydrangeas right now

    • Myrna
      July 11, 2023 at 1:26 am

      Good information sbout sealing them.Too hot to grow hydrangeas here. Catapillers wiped out most of my oleanders.
      For those that buy grapevine wreaths at craft stores, please examine them for wood beetles. Starts with a dark spot, then a whitish residue, then sawdust.Put them in a black garbage bag in the sun. An orchid basket from Home Goods one year hatched thousands.

  7. July 10, 2023 at 8:58 am

    Wow Mary, I am very impressed! The Limelight hydrangeas are indeed beautiful, it’s so good that you figured out how to save them. Using nail polish is quite brilliant! Gardening is a continuous labor of love that rewards with amazing eye candy~

  8. RS
    July 10, 2023 at 9:09 am

    Thank you for this timely post. Going to check my hydrangeas now as one is unhealthy.

  9. Allison
    July 10, 2023 at 9:16 am

    Yikes, Mary! I just noticed my hydrangeas have some holes in the stems and was wondering what was causing that! Thanks so much for this post!

  10. Donna
    July 10, 2023 at 9:20 am

    Very helpful. I have 3 baby limelights, I think they are called little limelights. Thank you. Photos are always fantastic.

  11. Dorinda Selke
    July 10, 2023 at 9:36 am

    Mary ~ we don’t have limelight hydrangeas but I am still going to go out and check all our other ones. Love learning all this important gardening info. Thanks so much.

    Hugs, Dorinda

  12. Shannon@Belle Bleu Interiors
    July 10, 2023 at 10:06 am

    Mary, I’m going to be doing some research on cane borers in my area. My limelights were planted a few years ago. We lost one and the other two haven’t done well this year. Thank you for making me aware of these borers. Gardening takes a lot of patience, and it seems you are always battling something. We have been having a terrible time with snails. They destroyed all of my dahlias this year. Japanese Beetles have also been relentless this summer. I haven’t spotted any the past week. Hopefully, they are well on their way out of here. Your limelight hydrangeas are breathtaking! The autumn arrangements with the dried ones are beautiful! Wishing you a wonderful week ahead!

  13. Karalee
    July 10, 2023 at 10:19 am

    Thanks so much Mary! I recently planted my first Limelight at our new home in Central Oregon (high desert!) and it looks as if it’s going to have a few blooms. I appreciate the info on what to look for next spring (and as my husband is a wood worker we always have plenty of wood glue around!) It’s due to your previous posts that I was even introduced to the Limelights…thank you again!

  14. July 10, 2023 at 10:54 am

    All great info since I can’t grow hydrangeas!

  15. Barbara
    July 10, 2023 at 11:21 am

    Thank you Mary, we have lime light and oak
    Leaf hydrangeas, we will be diligently watching them for this to me unheard of problem. your blog continues to be our favorite for your lovely photos and timely informative content

  16. Donna
    July 10, 2023 at 11:30 am

    Great information on the bores!!!!

  17. Chloe
    July 10, 2023 at 11:32 am

    My new-to-me garden is heavy on roses, but I would love to add hydrangeas. Thank you for a helpful post on what I might expect in terms of pests and remediation ideas.

  18. July 10, 2023 at 10:02 pm

    Mary, I’m sad you had to deal with the cane borers, but fortunately you have a solution and have made good progress. Fingers crossed that the problem is eradicated. Your lime lights are gorgeous. I asked for limelights to be planted in my new garden space last fall, but they couldn’t be found. I’m going to try again as a neighbor down the street just planted a row of topiary lime lights. They are gorgeous! Thanks for sharing this excellent information from your personal experience. Gardening is full of twists and turns.

  19. July 11, 2023 at 3:28 am

    Wow! Thank you for this informative post! I hope we never have to deal with cane borers but if we do I now know what to do! I am so sorry you had to deal with this!
    I cut back our Limelights extensively this past fall and made beautiful outdoor bouquets. I have beautiful growth now but no signs of blooms yet. I’m hoping they are just late this summer here in Pennsylvania. We did have a late frost… we shall see.
    Thank you once again for all your information!

  20. Patricia
    July 11, 2023 at 9:48 am

    Thank you Mary. My Limelight tree forms are blooming and looking robust. but I have filed this post away and plan to be on the lookout going forward. I must go out tomorrow and cut blooms as the branches on my tree are bending under the weight of the heavy flowers.

  21. franki parde
    July 11, 2023 at 10:41 am

    Oh, for Petes;s sake…THAT too yet??? franki

  22. Linda L Hovgaard
    July 11, 2023 at 12:56 pm

    I hope we don’t get those in Oregon! So sorry those buggers got into your Hydrangeas! What a pain! I’ve had unusual things happening in my garden this year. The latest being the neighbor’s 3 steers got out of their field and walked right through my vegetable and flower gardens. Unbelievably the only thing they destroyed was my garden basket that I use for transporting vegetables and flowers. They must have stepped on it and crushed the handle. They left me a deposit (not in a good way) and unwanted footprints but that’s about it. Whew! The guy upstairs knew how much work I’ve put into everything for months and months and led those cows right out! Lol!

  23. Colleen Hartwell
    July 11, 2023 at 3:04 pm

    Thank you so much for this positing. We have two huge Limelights and I checked them and yes, they have the cane borers! Much to my disappointment since we lost 75% of our landscaping here in TN due to a fast freeze in December. Ugh! At least I know now that we need to cut these down and apply the pruning sealer you suggested. I only wish someone would have told us about Boxwood blight so we could have protected our beautiful hedges!

  24. Michele M.
    July 12, 2023 at 12:56 am

    Oh my word, Mary – thank you! I have 3 limelight hyds and will check tomorrow. One has always done fabulously well, another medium well and the third just tiny. All bought, planted and treated the same, too. Boy the insects are soooo bad this year. We just didn’t get the deep freeze these past two winters to aid us in insect protection.

    I have pinned your post, Your expertise and wisdom is very much appreciated.

  25. Cyndi Raines
    July 13, 2023 at 12:11 am

    Thank you Mary for this important information. Glad yours are making a comeback, all due to your good pruning and tender care. They are beautiful! I hope my mop head will give me a few blooms but I think my neighbors aborvitie blocks too much sun now that they are so tall.

  26. July 13, 2023 at 8:04 am

    Great info, sure wish I could grow hydrangeas, I just never see blooms 😢

  27. Laura Dugas
    July 31, 2023 at 8:26 am

    I’ve had a limelight hydrangea for about 4 years now and it has never bloomed. It’s a very healthy green so I don’t want to cut it down and try again but I’m wondering if you have any suggestions for helping me get some blooms next year?

    • July 31, 2023 at 5:40 pm

      Hi Laura, Do they get enough sun? Limelights perform best when they get full sun or at least 6 hours of sun per day. If that’s not the issue then maybe they’re getting too much nitrogen from fertilizer (run off from your lawn fertilizer)? Too much nitrogen will produce foliage but not blooms. You want a fertilizer with a higher amount of phosphorus to produce blooms (the second number in fertilizer). Hope that helps!

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