Any suggestions for protecting crops from woodlice damage?

[Margaret]

I always get some damage from woodlice in my allotment greenhouses but this year is the worst ever   The plot flooded badly in the winter and so the creatures had their preferred damp conditions and of course there are wooden edgings and bark paths.  They may be finding conditions too hot to eat rotting wood (31C for the last few days) and so they are eating stems at soil level. Dwarf beans, tagetes, cucumbers and tomatoes have all been killed. Anyone know of a deterrent?

Many thanks

Margaret

[Lesley Cox]

People say woodlice don't eat living material, only stuff already rotting but I know this is not correct. I've watched woodlice (we call them slaters) clustered round various plants in troughs, eating like mad.

We have here a product called Ripcord. I think it is what is sprayed on new houses or fresh paintwork to deter spiders. I use it with total success to spray in my potting shed and associated areas and also to spray the trays into which I put pots, especially seed pots but anywhere at all where woodlice congregate, and I know they DO congregate in enormous numbers, especially in corners and in dark inaccessible places in the garden or work areas.

So - if you haven't too great an aversion to spraying in principle, (I don't like to spray but sometimes needs must), Ripcord does the job superbly. If you haven't that in the UK there will be something similar for the same purposes, I'm sure. It also kills spiders and flies and black beetles but doesn't affect slugs or centipedes. The spray - 40 mls to a litre of water and I keep it handy all the time - lasts for at leasts for 2 years.

[Martinr]

Margaret, assuming you are in the UK, any of the powder ant killers available in garden centres will kill woodlice as well. A little sprinkled round the base of the vulnerable plants should do the trick.

[Margaret]

Lesley, thank you for your advice and observations.  I have also read that woodlice do little harm but since I started growing veg I think they are a major pest eating every sort of plant material and occurring huge numbers. I try not to use sprays etc except in dire circumstances and I certainly would use a chemical on the slaters if they were on ornamentals. However I'm a bit worried about contamination of the veg. I've put some ant powder (Ripcord not available in UK) along path edging as a first line of attack.

Martin, thank you for suggesting ant powder. I had some in the shed and have tried it round some edges and under pots where there seemed to be thousands of the horrors. The powder contains permethrin.  Wiki says that it very persistent in the soil and so I better keep it away from the veg. I'll just need to hope that the horrors die of heat stoke! It was 30C + in SE london today.

[Alan_b]

There is a suggestion here, although I don't think you'll like it: http://huntergathercook.typepad.com/huntergathering_wild_fres/2010/03/why-not-eat-insects-potted-woodlice.html

[Margaret]

Awh Alan, that's a fantastic link. I've forwarded it to my husband who likes the idea of a stone age diet. I'll let you know if he acts on it but I won't be joining him!!!  Many thanks

[Lesley Cox]

We know that they only eat decaying matter isn't true. And I've seen them walking in straight lines, if only for short distances. Indeed, if they staggered about they may be more attractive as an edible, in that a certain alcoholic content may be implied. My hens REALLY love them.

[Margaret]

Lesley, do you think that if I spread a rumour that edible, inebriated woodlice can be found on my plot in large numbers I would get a queue of old boys (and maybe old girls) ready to hoover them up for supper. I remember when we were camping in our younger days and I was given a cup of coffee made on the camping gas stove. I discovered a woodlouse at the bottom of the cup on the last mouthful. What a fuss I made. How times change.

[Lesley Cox]

Yes Margaret, I do think you should go with this excellent idea. If I were you I'd put a good price on them too, say 5 GBP for a quarter cupful. Perverse as we are, it seems that the more expensive something is, especially to do with horticulture, the more we want it. Look at snowdrops. This could be a good retirement project over time.

[Anthony Darby]

I never understand the need to have a spray to kill spiders. The mass, in kg, of flies eaten by spiders in the UK every year is greater than the total mass of the UK human population. If fruit flies could increase their numbers at their optimum, which is each female producing a 100 new flies every fortnight, you could theoretically have a ball of fruit flies 90 million miles across in one year!

[Margaret]

Good idea, Lesley. I could do with some extra income and I might be able to entice more customers with some earwig garnish.

Anthony, I like spiders in the garden and take care not to break their webs when they are looking beautiful on dewy autumn mornings. However I don't find them endearing in the bath or in bed!!

[Lesley Cox]

I want to assure you Anthony, that I do NOT spray spiders specifically and have no problem with them in general, except, as Margaret says, in the bath or over me, on the ceiling when I lie in bed, especially if they're not in the same place next morning! But it is true that those spiders which climb into my sprayed seed trays will die, the smaller ones anyway. It is slaters which are my target and I have no feelings towards them, of sentiment or kindness. When I've paid many dollars for some possibly irreplaceable seeds, I'm not about to fail to protect them as they germinate. It must be admitted however, that spiders on paintwork are really filthy things, much more so than flies, and leave their droppings in large quantities

I have changed the top note about Ripcord to read 40 mls not 440, in case anyone is tempted to  use it.

[Anthony Darby]

Quite so Lesley. Interesting they are called by their Scottish name slater, but I suppose it is to be expected, judging by the Scottish influence in New Zealand. It's products specifically aimed at spiders, like "Miss Muffet's Revenge" that I have the problem with. Not something you'd use in the bath. There seem to be lots of fiendish concoctions here - like Resveratrol. What do you spray that on?

[Margaret]

Anthony, I didn't know either product you mentioned and have googled them. Miss Moffat's Revenge must be made for people with a spider phobia. I can't imagine a gardener wanting to get rid of spiders.  I'm confused about the Resveratrol it seems to be a health supplement over here!!

[Anthony Darby]

I've only heard both products advertised on the radio. Anything with a name like Resveratrol should be some kind of pesticide.