Saturday 7 June 2014

Viburnum Beetle

Making Life Easier
Psychological approach?
      I've come to the conclusion that the apparently peaceful pastime of gardening is actually do-it-yourself warfare: the more we try to control nature, the more bloody minded it gets and the greater the need for creative thinking:

      We recently spent a few days at Stratford Upon Avon and I made what is becoming a habitual visit to Hidcote Manor gardens. As usual, the gardens impressed but something which caught my eye was an area signed 'The Poppy Border'. As a gardener plagued with the pretty but uncontrollable Welsh poppy, I recognised this as a masterpiece of adaptation - the psychological approach to a problem using the 'if you can't beat the buggers, join 'em' technique. I've been thinking of employing the same strategy by creating 'The Dandelion Border', 'The Willow-herb Bed' and maybe even 'The Marestail Bank'. This would be achieved with a complete lack of effort on my part except for the making of the signs. However, gardening being what it is, I can almost guarantee that the dandelions would suddenly and inexplicably be over-run by Dahlias, the willow-herbs by Phlox and, for the first time in history, the marestail would inexplicably disappear.

      If the Hidcote gardeners were allowed to sit back with satisfied smiles, it wasn't for long because the enemy was advancing along another front: I was trying to identify a large and, I thought, exotic shrub with amazing lacy leaves when it became apparent that it was simply the common Viburnum opulus. The Viburnum beetle had reduced the foliage to a tracery of veins and, when I looked closer, I could make out the tiny caterpillar-like larvae wreaking their havoc. When I listened carefully, I swear I heard munching.
Viburnum beetle damage
Viburnum beetle larva
      The larvae feed in late spring (mid April to early May) and that's the time to zap them. Pyrethrum is the best organic spray, although the adults, which turn up to feed later in summer, are most effectively controlled using something like Bayer Sprayday Greenfly Killer. However, in my experience, it isn't easy to spot the adults and, as the main damage is already done by the time they turn up, early application of Pyrethrum is the best bet.
Hosta sieboldiana - off the menu?
      The chemical approach to a lot of pest problems brings to mind the open stable door and lack of horse scenario and it's much easier to grow plants which have a natural resistance to the main enemies: a big problem with gooseberries is American mildew and varieties like Invicta, Jubilee and Pax (among others) are fairly impervious to its ravages. Similarly there are blight resistant potatoes, club root resistant cabbages and cauliflowers, carrot fly resistant carrots, and many others. Even slug caviar - Hosta, has some varieties which, though not completely immune, seem to be far less palatable than others. Those with blue, thick and puckered leaves fit well into this category.

For more about slug control go to Organic control
For more about carrot fly problems go to Carrot fly problems





2 comments:

  1. Does spraying Hosta with WD40 count as organic control?!!!!!!! It works!

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    Replies
    1. Don't know whether it's organic - I suspect not - but it certainly stops them squeaking.

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