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Forced Hydrangea Pruning

Hi guys, hope everyone is doing well and staying safe. I have a quick question about the pruning of Hydrangeas that have been greenhouse forced. 

A few weeks ago we bough two beautiful Hydrangeas in full bloom, and repotted them in our garden. We unfortunately weren't aware of the concept of "greenhouse forcing", and the flowers quickly wilted. At the moment all flowers are brown and brittle (dried out), and most leaves are dark green and droopy with greenish-black tips (not dry tho, still soft and malleable). However, the stems are still strong / firm and green, and there are a few healthy-looking baby leaves growing under the big droopy ones. 

So my question is, should we prune these Hydrangeas? If yes, what should we cut and what should we avoid cutting? I mean, in my mind it would make sense to clip the dead flowers and droopy leaves, whilst preserving the baby leaves... but I'm wondering wether we'd also need to cut back the stems or something like that. 

Thanks in advance, any advice will be highly appreciated! 

Posts

  • BorderlineBorderline Posts: 4,687
    Difficult to answer without seeing a photo and the type of Hydrangea. At this time of year, if it is kept in a greenhouse, it's fine to clip off the damaged and dead top parts. 

    Droopy leaves can indicate being in an area that is too hot and wilting, or not watered well and the whole plant is dehydrated. They may not like the swings in temperatures in your greenhouse. I would move them outside and tuck them against a north westerly wall so they get good air circulation. Keep well watered and avoid keeping in an area with too much sun. They prefer part shade if you can give them that.
  • luis_prluis_pr Hurst, Texas Zone 8aPosts: 123
    edited April 2021
    I agree too. You can deadhead the spent blooms unless you are the kind of gardener that leaves them until they fall down on their own. I used to deadhead the blooms when they turned brown in the Fall but now, I have so many that deadheading is not practical ;o)). If you want to cut them off, you can cut the peduncle, the little string that attaches the bloom to the stem.

    I would not prune either. Other than pruning stems that dried out during winter or pruning to remove crossing branches, hydrangeas rarely need to be regularly pruned.

    The signs of droopy or wilting leaves shows that there is some form of stress that makes the leaves lose moisture faster than the roots can absorb more water. Examples of these conditions: temperatures above 29C; windy conditions; lack of water or lack of enough water; too much sunlight; disturbing roots when transplanting, etc.

    When the plants wilt, you can usually test the soil with your fingers and give them more water if the soil is dry or almost dry. This is a common issue with new hydrangeas in Year 1 but will occur less frequently once the plant becomes established in your garden and develops a larger root system. You can also: maintain 5-10 cm of organic mulch under the plant all year around up to the drip line in order to minimize soil evaporation, protect the tiny, shallow roots from temperature extremes and to provide additional nutrients as the mulch decomposes; relocate the pot or the plant if it gets sun after 10-11am (or thereabouts); switch rocky mulch to pine needles, hardwood mulch, etc.; add wind blocks or relocate the plant to a less winy location; temporarily provide additional shade using outside umbrellas or outside chairs (I try to acclimate new hydrangeas slowly to the sunlight prior to planting).

    I suspect you may have a Big Leaf Hydrangea but like Borderline suggested, pictures of the leaves and blooms would help us identify them. Big Leaf Hydrangea, aka French Hydrangea or Hydrangea macrophylla, develops flower buds inside the ends of the stems several months after the current set of flowers open. This can occur out of the normal time this year but should sync up with what is normal for your location in Year 2. For example, where I live, I try to have any pruning done by the end of June because I already know that I will have some of these invisible flower buds by the end of the summer or early fall. The flower buds stay inside the stems and then open in Spring and resemble tiny broccoli heads. I am not sure about the variety that you got but there are some varieties that will also produce blooms again in the summer from new growth (stems) that started growing this spring.

    Your hydrangea macrophylla, if it is indeed a macrophylla, may have pom pom-like blooms that are called mopheads or a "flat" bloom that is called a lacecap bloom form. Lacecap blooms have the mophead flower's sepals usually growing around the actual fertile flowers.

    The link below has lots of hydrangea pictures that can help you identify which type of hydrangea you have. Plants purchased in plant nurseries also contain a label that identifies the type and the cultivar name. But plants purchased in some grocery stores and florist stores only have a small tag that reads something like "Hydrangea", "Blue Hydrangea", etc. and nothing else (luckily, those florist hydrangeas tend to be hydrangea macrophyllas) but feel free to check out the website. I find it has very useful care/maintenance information too.



  • Difficult to answer without seeing a photo and the type of Hydrangea. At this time of year, if it is kept in a greenhouse, it's fine to clip off the damaged and dead top parts. 

    Droopy leaves can indicate being in an area that is too hot and wilting, or not watered well and the whole plant is dehydrated. They may not like the swings in temperatures in your greenhouse. I would move them outside and tuck them against a north westerly wall so they get good air circulation. Keep well watered and avoid keeping in an area with too much sun. They prefer part shade if you can give them that.
    Hi there, thanks for the reply! I'll attach the pictures to this post.

    Pictures 1 & 2 (3153, 3155) show the two hydrangeas we purchased recently. They came to us in full bloom and we placed them in our garden after repotting them. We used multi-purpose compost from GoodHome, and we've been watering them roughly once a week. I check the soil daily to make sure there's enough moisture. I've also included Picture 3 (3157), which is a hydrangea we purchased in the summer of 2019. As you can see this year's baby leaves look healthy, and we've never had any problems with it over the years... it always blooms beautifully. The two new plants get the exact same amount of sun / shade, the exact same amount of water, and were placed in the exact same type of soil.

    I actually came to this forum for advice earlier in the month when they first began to wilt, and the general consensus was that these plants were greenhouse forced by our local flower market and they are looking unhappy because we've moved them outside. We were told there is not much we can do about it as hydrangeas are not supposed to be in full bloom at this time of the year (for weather context, I'm located in south east London). 

    I'm guessing these blooms aren't going to come back to life, which is why I'm wondering if I should snip them... then again I'm really not sure how to proceed. What do you think? 
  • PianoplayerPianoplayer Posts: 624
    My guess is that it isn't a watering problem (as you are doing that!) - they are more likely to have been caught by the overnight frosts. Once you are sure that the frosts are truly over (whenever that will be!) then I am sure you can cut off the dead flowers and shoots, and just keep watering and feeding. The third one looks good, so hopefully the new ones will adapt to being outside as it has done.
  • luis_pr said:
    I agree too. You can deadhead the spent blooms unless you are the kind of gardener that leaves them until they fall down on their own. I used to deadhead the blooms when they turned brown in the Fall but now, I have so many that deadheading is not practical ;o)). If you want to cut them off, you can cut the peduncle, the little string that attaches the bloom to the stem.

    I would not prune either. Other than pruning stems that dried out during winter or pruning to remove crossing branches, hydrangeas rarely need to be regularly pruned.

    The signs of droopy or wilting leaves shows that there is some form of stress that makes the leaves lose moisture faster than the roots can absorb more water. Examples of these conditions: temperatures above 29C; windy conditions; lack of water or lack of enough water; too much sunlight; disturbing roots when transplanting, etc.

    When the plants wilt, you can usually test the soil with your fingers and give them more water if the soil is dry or almost dry. This is a common issue with new hydrangeas in Year 1 but will occur less frequently once the plant becomes established in your garden and develops a larger root system. You can also: maintain 5-10 cm of organic mulch under the plant all year around up to the drip line in order to minimize soil evaporation, protect the tiny, shallow roots from temperature extremes and to provide additional nutrients as the mulch decomposes; relocate the pot or the plant if it gets sun after 10-11am (or thereabouts); switch rocky mulch to pine needles, hardwood mulch, etc.; add wind blocks or relocate the plant to a less winy location; temporarily provide additional shade using outside umbrellas or outside chairs (I try to acclimate new hydrangeas slowly to the sunlight prior to planting).

    I suspect you may have a Big Leaf Hydrangea but like Borderline suggested, pictures of the leaves and blooms would help us identify them. Big Leaf Hydrangea, aka French Hydrangea or Hydrangea macrophylla, develops flower buds inside the ends of the stems several months after the current set of flowers open. This can occur out of the normal time this year but should sync up with what is normal for your location in Year 2. For example, where I live, I try to have any pruning done by the end of June because I already know that I will have some of these invisible flower buds by the end of the summer or early fall. The flower buds stay inside the stems and then open in Spring and resemble tiny broccoli heads. I am not sure about the variety that you got but there are some varieties that will also produce blooms again in the summer from new growth (stems) that started growing this spring.

    Your hydrangea macrophylla, if it is indeed a macrophylla, may have pom pom-like blooms that are called mopheads or a "flat" bloom that is called a lacecap bloom form. Lacecap blooms have the mophead flower's sepals usually growing around the actual fertile flowers.

    The link below has lots of hydrangea pictures that can help you identify which type of hydrangea you have. Plants purchased in plant nurseries also contain a label that identifies the type and the cultivar name. But plants purchased in some grocery stores and florist stores only have a small tag that reads something like "Hydrangea", "Blue Hydrangea", etc. and nothing else (luckily, those florist hydrangeas tend to be hydrangea macrophyllas) but feel free to check out the website. I find it has very useful care/maintenance information too.



    Thank you so much for all the useful information! 

    Before anything else, please have a look at my reply to the previous commenter, as I've included the pictures and a bit more information about the flowers. 

    After looking at the link you've sent, I think all of our hydrangeas are Original Endless Summer, as the new leaves and blooms grow out of the previous year's branches. At least I'm 100% sure our older hydrangea (2019) is of that variety, and the new ones look exactly the same as the older one when in full bloom. 

    My main doubt is wether the hydrangeas will spruce up later in the year when climate becomes more adequate, or wether I need to snip off all the dry blooms and wilted leaves... although my fear is that nothing will grow back this year. Based on the pictures attached to the comment above this one, what do you think is the best course of action? 
  • My guess is that it isn't a watering problem (as you are doing that!) - they are more likely to have been caught by the overnight frosts. Once you are sure that the frosts are truly over (whenever that will be!) then I am sure you can cut off the dead flowers and shoots, and just keep watering and feeding. The third one looks good, so hopefully the new ones will adapt to being outside as it has done.

    Hi there, thank you so much, your comment definitely gives me some renewed hope that these hydrangeas will turn out ok! I was afraid that it was too late in the year to be cutting off the flowers and shoots. To be honest, coming from a tropical country, my knowledge of the seasonal cycles of specific plants is still very scarce.

    Now that you've mentioned it, I think that we purchased these hydrangeas in the middle of a rather uncharacteristic early spring heat wave, which was immediately followed by a few extremely frosty days... so yeah that makes a lot of sense. Anyway, I'll make sure to wait until the weather is a bit more consistently warm before I do any cutting. 
  • PianoplayerPianoplayer Posts: 624
    Yes - you are absolutely right. A lot of comments on here about the same problem. It's nothing you've done wrong. If you wait a while, you will be able to see clearly what is dead (and can be removed) and what has recovered!
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