Thursday, 12 February 2015

Friendly Garden Sprays

My armoury - The most harmless of ingredients.
Not every insect needs to be obliterated in order to protect our crops. If we do that, we eventually obliterate most of our wonderful natural world.
But I can't deny that there are some insects (general term, even if they don't strictly all have six legs) which are bad news. Whilst it may be possible to control them by encouraging their predators, such as birds, hoverflies, ladybirds into the garden, this noble aim is sometimes a little idealistic in the real world. Not that we shouldn't try.
Besides, it's not just insects which threaten. I've probably had more trouble from fungal organisms - mould, rust, blight... than from creatures. Then there are bacteria and viruses, which we can't even see until their effects are all too obvious.

So, to cut to the chase, I know that I should probably spray my orchard trees and I know that I ignored spider mite at my peril in the polytunnel last year. But I really am not willing to smother everything with nasty chemicals. I may as well give up what I do and go buy it all from the shop if I take that approach.

We are therefore looking at home-made sprays. There has been a huge reduction in the number of sprays which can be used by gardeners in recent times. It's probably mostly good news as far as sensible, organic gardening goes, but the problem is the red tape. Apparently it costs in the region of £3million to get all the data required by European Law to license a pesticide. The effect of this is disastrous (similar to rules they have tried to push through about licences for selling seeds). It effectively means that the big multinational corporations gain a stranglehold on the market and many traditional organic remedies have fallen by the wayside. Unfortunately, I cannot help but think that yet again politicians have, inadvertently or not, allowed corporate lobbyists to tread all over the common people. All these rules which are allegedly to protect the consumer (labelling laws being another example) inevitably punish the small producer and rarely actually achieve what they set out to achieve.

I, however, am a man of principle, and am not about to be forced into supporting multinationals who care less about the fate of the planet than about lining their pockets and controlling peoples spending patterns.
Therefore I have determined to make my own sprays. I have seen it written that any home-made spray is illegal to use, even if it's in your own garden and you don't sell any produce. However, even if this were true, I would ignore it since it is plainly unjust and bonkers. But it appears not to be true anyway. Here is the link to the Health and Safety Executive's advice on this matter. I've also copied the relevant text at the end of this document, in blue.

Health and Safety Executive Advice On Using Pesticides In The Garden

Gardener's have been making up their own concoctions for years. We're a thrifty lot. But these have traditionally included some rather dodgy ingredients such as tar and tobacco. I am not even really comfortable with something like rhubarb leaf soup. Just because you can make your own nasty chemicals does not necessarily mean that you should. And many nasty chemicals have natural origins.

But the main ingredient necessary to fight off insects is... soap. And not just any old soap, but pure vegetable soap. They are not allowed to call it insecticidal soap anymore. You can guess why. £3 million.
I researched a lot and ended up buying a container of castile soap over the internet. Compared to Fairy Liquid or Palmolive, it's not cheap. But you only need a tablespoon or two in a 5 litre sprayer, so it goes a very long way and most definitely ends up much cheaper than any commercial alternatives.
It's worth bearing in mind that soap will not just kill the insects you want it to, so sparing and targeted use is still necessary.
In with the soap goes some vegetable oil, to make it cling to the leaves and stems.You can use any, but rape oil (the American sites seem to refer to it as Canola) is particularly good as it's very thin and doesn't clog the sprayer.
If you search the supermarket shelves, you'll find it not too expensive. Again, you don't use much.

And that's basically it.

There are things you can add. Chilli and garlic are commonly recommended (also supposed to ward off rabbits and maybe deer).
Hydrogen Peroxide is a very natural substance to use too, though you need to know what concentration to use. It's also good against fungi. I know you're thinking "bleach" but it's actually just the H2O with an extra O!
And bicarbonate of soda is good if you're main concern is fungal diseases.

So, with the exception of the hydrogen peroxide, we're basically talking common cookery ingredients that you'd be quite happy to put in your mouth (maybe not the chilli!), so I am quite happy that when I spray I am harming as little as possible.

As for the red spider mites, which decimated my indoor climbing beans last year, I've removed all the places where they might be able to hide away for the winter and added a little essential oil to the mix - lemon eucalyptus in this case, though there are several others which would be just as effective.

See here for more detail.

I spent ages searching the internet for my spray recipes, so here's what I have settled on:
Apologies for the strange mix of imperial/metric. It's my age.

My orchard winter wash recipe:

250ml Vegetable Oil
2 tbsp. liquid soap
1 gallon (4.5l) warm water

Just shake to mix, then spray each tree to coat the bark as much as possible. Choose a nice still day, but preferably not when there will be rain in the next 24 hours or a frosty night. Easier said than done in January and February. Be patient and wait for the right time, as long as you spray while the trees are still dormant.
Don't use on walnuts (I've no idea why! I read it somewhere.)

My red spider mite recipe:
As above, but with the addition of 10 drops of Lemon Eucalyptus Oil (bit of a guess really).

You may want to scale this down, as it will make 5 litres. Spray on all leaf surfaces (not so easy getting at the undersides, but do the best you can). I also sprayed all nooks, crannies and crevices in the tunnel. Don't spray on a really hot, sunny day (unlikely at this time of year, but quite possible once your polytunnel is full of greenery) otherwise the soap may damage the leaves.

I'll let you know if they work.
Meanwhile, here's the text of that HSE advice. I think I'm safe,

Can I use home-made remedies to control pests, diseases and weeds in my (home) garden?
HSE are aware that some gardeners routinely use home-made remedies that are not authorised to control pests, diseases and weeds. In some cases these remedies are simple physical barriers and are outside the scope of UK and EU regulations. In other cases these remedies involve the use of chemicals either from foodstuffs, like coffee grounds, or from household products which are not normally intended to be used as pesticides.
Part of the legal definition of a plant protection product takes into account the intended use of the product. For example garlic extract sold as a foodstuff doesn’t require authorisation under plant protection product regulations but garlic extract sold as an insecticide does. In practice this means a number of own use home-made remedies such as beer traps or coffee grounds fall outside the scope of regulations.
However this does not mean that use of these remedies including use of common household chemicals as a pesticide is without risk or that it is always legal. For example in circumstances where a home-made remedy was supplied to another user (whether free of charge or not) this may fall in scope of the regulations ,and if so would be illegal without an authorisation. In this sort of circumstance, where HSE (or other enforcing authorities) obtain evidence of such a supply or use we would need to consider appropriate and proportionate enforcement action.
HSE’s policy on enforcement and the circumstances in which enforcement is appropriate is set out in more detail in our Enforcement Policy Statement .


  1. Very interesting post. I don't think I have used chemical remedies in all the years in my last garden. As far as insects are concerned I did not make any pre-emptive interventions but just kept a vigilant eye. Something like aphids I just rubbed of with my fingers and after a couple of goes this always seemed to work with roses and globe artichokes which I found most susceptible. I also used soapy water but will look into vegetable soap. Fungal attacks are a different matter but good husbandry goes a long way in preventing spread. I've recently moved a plot with 4 acres so this might throw a few bigger challenges compared to what I have been used to.

  2. Absolutely, Phil. In fact it's very rare that I would see any obvious pests such as aphids in my veg plot, soft fruit or orchard. The main pests I have to hunt for by eye are slugs and caterpillars, but the poultry do a good job of knocking these and other pests back over winter as I turn the soil. I do absolutely loads to encourage natural predators and companion planting does an excellent job too. But however vigilant or tidy you are, the likes of red spider mite, scale insects hiding in the bark of orchard trees or windborne blight are much more difficult to tackle, particularly when you go past a few small beds, and they will arrive in the end whatever you do. Biological controls are possible for the likes of the mites, but are not a cheap option. Fungi and moulds are becoming more and more of a threat as we get these warm, muggy summers.
    I intend to look into using milk-based spray for these this year when they happen.
    I would certainly look into using detergent free soap.


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