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Gunnera problem – leaves turning brown and holes appearing

My gunnera is either being eaten by a pest, or has a disease. Any ideas from these photos?

It has been fine in previous years, but this year I've had to cut 5 or 6 leaves off as they'd turned totally brown and were covered in holes.

Even some of the young leaves are already dark underneath (see pics).

I've been spraying it with Neem Oil now and then as a pest deterrent but it doesn't seem to make any difference.

Any help would be much appreciated.

Cheers, George.

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Posts

  • GuybrushGuybrush Posts: 172

    I've only recently bought a gunnera so I'm no expert but I did read that the leaves (and all of it really) need to be moistened regularly as they can dry out and go crispy. They come from cloud forests were the air is perpetually damp.

  • ObelixxObelixx Vendée, Western FrancePosts: 28,074

    Water generously every day.  Or get it in the ground in a moist spot.

    I have one I've been nurturing in a big pot so I could take it into shelter to get it through cold Belgian winters and in this new garden it's in the shade awaiting clearance of the pond edges so I can plant it out and I am giving it a good drenching every day.  Even so, I've had to remove the largest leaves in the heatwave as they were going brown and crispy.

    "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
  • Nanny BeachNanny Beach Posts: 7,910

    Mine is similar, on pond margin, but very little rain, (just had a quick shower, but so hot its dried out again) so I have soaked it, and topped up the pond.

  • Thanks all for the responses.

    I do water mine pretty generously everyday, so do you still think these brown areas on the leaves / stems are caused by lack of moisture?

    Also, any explanation for the holes in the leaves? I was thinking something small has been munching on them...

    Thanks for your knowledge!

  • Nanny BeachNanny Beach Posts: 7,910

    they are marginal plants, need a really boggy area, our pond just went down a couple of inches in the hot weather, that was enough to over dry it.

  • MuddyForkMuddyFork North HampshirePosts: 435

    I cannot imagine anything that would munch these very tough leaves.  I think the holes may just be where very crisp foliage has fallen out.  Gunnera leaves can be burnt by the sun which given the weather we have had may be the cause of the browning.

  • Ok cool, I'll up the watering and ensure it stays totally out of the sun.

    Cheers!

  • GuybrushGuybrush Posts: 172

    Also use a good nitrogen feed every couple of weeks in the spring/summer.

  • Hi Everyone, regarding Gunera, my larger leaves don’t seem to be retaining their stature, I have been watering each day during hottest weather. Perhaps I let that slip for one or two days is that enough for it to suffer? The flowers are doing well. Should I cut off The weakened stem and compost? We started with 2 small plants now how 4, should I cut away and replant at a distance? Helps? Please I love these babies!
  • bertrand-mabelbertrand-mabel Posts: 1,710
    We have 2 Guneras (for many years) and each year as they start to grow we have frosts and they are knocked back. This year this has happened 4 times and we thought that that they wouldn't get going at all.
    The sun this year has been so intense for so long that leaves have been burning even though watering has been done.
    They have but slowly. The flowers are developing.
    They are planted in boggy conditions and sheltered.
    We don't cut back the damaged leaves.
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