Topic: HOMEMADE PESTICIDES

[SandyLaner]

According to the experts on television last night, Wild Things Ch4, there is no natural predator that attacks rhododendrons because the leaves and everything else are toxic to insects. Does anyone know if we can take the leaves and steep, boil, distill or otherwise make a pesticide from them?

Tomato leaves were not that succesful but, given the rain we had I wasn't surprised. I really don't want to spend on chemicals that kill everything on the plot.

[Chrispy]

Shop bought chemicals have their faults, and I totally understand those who do not want to use them.
I myself keep chemical use to a minimum and very rarely use a pesticide.

However, if you buy a pesticide, it would have been developed, tested and regulated so to do the best of the job it is designed to do with the minimum of bad effects to the rest of the environment and your safety.

I can not begin to understand why anybody would think that boiling up a load of unknown toxins to unknown concentrations and with no idea what detrimental effects they may have is in some way a better way to go.

[SandyLaner]

The idea was that someone would actually know and pass on that knowledge. I fully agree with some of your reply but remember, it wasn't bumbling amateurs that concocted Agent Orange or for that matter Thalidomide, Debendox, Zyklon B or even whatever it was they released in Bhopal.

Thanks anyway

[Digeroo]

Pyrethrum originally came from plants.

[Jayb]

Perhaps a search on google may have information you seek SandyLaner. Sorry, I'm with Crispy on this one and I'm not sure this forum would be the right place for experimenting with the unknown.

[ed dibbles]

Can't help with the rhody leaves I'm afraid but an initial small trial surely can't hurt and you never know till you give it a try.

After all there isn't a commercial treatment for onion white rot and we are told it is untreatable. But there is now a growing body of evidence that spreading pulverized alliums (onion, garlic etc) on the onion bed a few months in advance of planting the onion crop reduces white rot noticeably.

Likewise it is against EU regs to use soapy water to control aphids. But nothing to say you can't wash your plants and if a few aphids succumb, well, it's just collateral damage.

[Digeroo]

But it is not just the case of killing the bugs it is about not killing the person who subsequently eats the plants.  Various plants are suggested for use as pesticides, including tobacco and chilli but not sure rhodedendron is on the list.  Do Rhodedendrons perhaps also have herbicides in them, not much grows underneath them?

[Obelixx]

Why do you need pesticides?

I never use any apart from wildlife friendly slug pellets.  I find that feeding the birds all year round means they're still here to take aphids and caterpillars and I can use nets on brassicas if needs be.

Other pests like lily beetle can be hand caught and squished and their larvae forms blasted off with the hose pipe.

[SandyLaner]

Ye gods!! I asked if anyone knew of any preparation we can make from rhododendron leaves and out came the pulpits. A simple NO would suffice.

[BarriedaleNick]

We are not really bringing out the pulpits here SandyLaner jusy trying to offer sensible advice. This is a slightly delicate area for the forum.  One, many of us have quite strong views on the use of pesticides in general (and we have had a few good barneys in the past) and two, we are adventuring into the realms of illegality when discussing home made pestiicides which could possibly be damaging to the forum. 

Personally I find the idea of plant based preparations absolutely fascinating but I would hesitate to post formulas or techiques here.  I know that may sound a little odd with this being a gardening forum but we can be an odd bunch!!

Also this is a discussion forum - once a topic is started it can take on a life of its own!!

[Melbourne12]

It may be worth reposting my correspondence with the Health & Safety Executive on this topic:

Can you ask the Chemicals regulation Directorate the specitic reference to the act of parliment which makes home made pesticides illegal so we can read the actual.

It seems stupid to ban everything sensible, and still allow aminopyralid to wreak havoc on the weedkiller front.

The relevant correspondence is copied below:

Posted At: Monday, August 29, 2011 12:12 PM
Posted To: Inform
Conversation: Legality of home made pesticides
Subject: Legality of home made pesticides

Good afternoon,

I moderate one of the many gardening forums (allotments4all.co.uk), and a question has arisen over the legality of "home brew" pesticides.  Many people use infusions of, for example, rhubarb leaves against various insect pests.  Some people are concerned that, because such folk remedies are unlicensed, they are therefore illegal.

We are not here talking about attempts to create banned pesticides in the garden shed, but simply traditional formulations. Neither is there any question of offering such products for sale.

I'd be most grateful if you could clear this matter up for us.  Any advice on the subject would be most helpful.

Regards

From: Inform <Pesticides@hse.gsi.gov.uk>
To: (Melbourne12)
Sent: Wed, 31 Aug 2011 15:12
Subject: RE: Legality of home made pesticides

Dear ....

Thank you for your enquiry.  Strictly speaking, the use of home-made insecticides, herbicides and other pesticides – the term “pesticides” is used in legislation as an umbrella term to cover any substance, preparation or organism prepared or used for destroying any pest (where pest means any organism harmful to plants or to wood or other plant products, or any undesired plant; or any harmful creature) - would be covered by the Control of Pesticides Regulations 1986 which apply not only to recognised pesticides but also to substances, preparations or organisms prepared or used as if they were pesticides.  These are UK regulations that require that all pesticides must have been granted approval by the relevant Government ministers before they can be legally advertised, sold, supplied, stored or used so the use of home-made pesticides would represent the use of unapproved pesticides and this would be an offence under the Regulations.

We are aware that some gardeners and allotment users do make their own pesticides from household chemicals or other substances to control particular pests; for example, using rhubarb leaves as in your example, or using coffee or salt to repel or kill slugs.  However, we cannot condone or encourage the use of such pesticides because such use is likely to result in the user committing an offence under the regulations even though such offences are unlikely to be prosecuted; it is usually difficult to obtain appropriate evidence and it is not generally in the public interest to do so.  This does not mean that appropriate enforcement action, including prosecution, would not take place - while some of the home-made pesticides that gardeners have produced over the years are unlikely to have health or safety implications, others most definitely could - and where evidence was obtained that the use of such substances had led to serious environmental or health consequences or where “home-made” pesticides were being sold or supplied to third parties, this would potentially result in prosecution for a criminal offence.

Similarly, we would not encourage the publication of information relating to the ingredients of home-made pesticides and/or methods of manufacture or use, although we have no actual powers to prohibit this.  However, the publication of such information could be interpreted as encouraging the use of unapproved pesticides, and this could, potentially, result in the person publishing the information also committing an offence.  We would therefore hope that anyone considering publishing information in this area will avoid references to specific home-made pesticides or their ingredients and methods of manufacture and use.

By comparison, the use of home-made fertilisers such as compost or comfrey tea are not directly covered by any legislation, although we would probably not recommend that anyone try and manufacture their own “commercial” NPK fertilisers at home.

I hope that this answers your questions but if you would like clarification or further information on any point, please let me know.

Yours sincerely,

Ian Rowland

Communications Branch
Chemicals Regulation Directorate
Health and Safety Executive
Mallard House
Kings Pool
3 Peasholme Green
York
YO1 7PX

Tel: (+44) (0)1904 455775
Fax: (+44) (0)1904 455763
Email: pesticides@hse.gsi.gov.uk

Posted At: Thursday, September 01, 2011 11:55 AM
Posted To: Ian
Conversation: Legality of home made pesticides
Subject: Re: Legality of home made pesticides

Dear Mr Rowland,

Thank you very much for your comprehensive reply.

Just one small clarification, if I may: you say in your first paragraph, "the use of home-made pesticides would represent the use of unapproved pesticides and this would be an offence under the Regulation"  and in your second, "such use is likely to result in the user committing an offence under the regulations".

I have browsed the regulations, and I've seen the derogation for the use of foodstuffs as an attractant or repellant, such as jam in wasp traps or peanut butter in mousetraps - but presumably not beer in slug traps, where the attractant is also the biocide.

I also understand that pursuing minor offences may not be in the public interest, and that there may be other offences to do with consequential environmental or personal damage.  But as far as the use of unapproved pesticides is concerned, do I take it that it is always in contravention of the regulations, no ifs, no buts?  In other words, it's what lawyers refer to as an absolute offence?  Or is there some doubt, depending on circumstances?

Thanks for your help

Regards

From: Inform <Pesticides@hse.gsi.gov.uk>
To: (Melbourne12)
Sent: Mon, 19 Sep 2011 14:25
Subject: RE: Legality of home made pesticides

Dear ....

Thank you for your enquiry.  The use of an unapproved pesticide is an absolute offence in that the pesticide is either approved or it is not, but it is only the courts that can determine whether or not an offence has been committed; if someone is charged with or prosecuted for using an unapproved pesticide; it is only if they are found guilty that they would be deemed to have committed the offence.  Since I was describing the general position, I had to take account of the fact that there might be reasons why a court would not find someone guilty in particular circumstances.

I hope that this answers your questions but if you would like clarification or further information on any point, please let me know.

Yours sincerely,

Ian Rowland

Communications Branch
Chemicals Regulation Directorate
Health and Safety Executive
Mallard House
Kings Pool
3 Peasholme Green
York
YO1 7PX

Tel: (+44) (0)1904 455775
Fax: (+44) (0)1904 455763
Email: pesticides@hse.gsi.gov.uk

As a postscript, Mr Rowland makes one small omission in his second reply.  It would be up to the Crown Prosecution Service, not the courts, to decide whether to prosecute.

I don't want to make too big a thing of this, since the letter from Mr Rowland makes it clear that you're unlikely to be prosecuted for spraying rhubarb tea or washing up liquid.  But technically you ARE committing an offence.

[Melbourne12]

According to the experts on television last night, Wild Things Ch4, there is no natural predator that attacks rhododendrons because the leaves and everything else are toxic to insects. Does anyone know if we can take the leaves and steep, boil, distill or otherwise make a pesticide from them?

Tomato leaves were not that succesful but, given the rain we had I wasn't surprised. I really don't want to spend on chemicals that kill everything on the plot.

Notwithstanding my post above, I've been having a little internet search to see what it is in rhododendrons that deters insects.  But it looks as though there ARE insect predators that attack and even kill rhododendrons in many countries.  Even in the UK, leaf hoppers and vine weevils can attack them.  I suspect that the reason that rhododendrons don't suffer too badly is that our weather is too cool for their worst enemies.

The RHS say, "Rhododendrons are susceptible to many and varied pests and diseases including vine weevil, leafhoppers, scale insects, bud blast, honey fungus, and lime-induced chlorosis if the soil is not sufficiently acid."

So I think the programme was wrong, and you're unlikely to get an effective insecticide from infusing the leaves!

[chriscross1966]

I was going to say there's a perfectly easy way to get rid of rhododendrons, lime the soil a few times and they die.... also there was a perfectly good treatment for onion white rot that is still available in America called Armillatox... however over here it isn't licenced for use as a pesticide (it costs a fortune for the licence adn they're not a big company) so it can only be used as a cleaning agent.... The American application rate is a 1% solution (100ml in 10 litres) at 5 litres a square metre (about a gallon a square yard)....

[Chrispy]

Have a read of this, and beware of gifts of honey.

http://en.wikipedia.org/wiki/Rhododendron#Toxicology

[Kea]

Rhubarb infusion as a foliar feed! Etc

[Robert_Brenchley]

If you want to make your own pesticides, stick with known recipes like rhubarb infusion. Rhododendron is sufficiently poisonous for the honey to be decidedly bad for you. There have only been a couple of mild cases here since it doesn't produce much nectar in our climate, but it's well known in the Caucasus. There's a famous story about a force of Greek mercenaries being chased by the Persians, which disabled the enemy by leaving out poisonous honey for them to find. They ended up too ill to continue the pursuit.

[laurieuk]

There is now a possible cure for white rot with onions. When you harvest a crop of oniions attacked by white rot you leave behind the spores of the fungus that then go dorment until another allium crop is planted( up to 7 years) but if you water the ground as soon as the crop is clear wiht a solution of garlic the spores germinate then  as there is no allium plats for it to live on the spores die. This is being used conmercially now I have a good crop at the moment where I have used  this method. Al

Can't help with the rhody leaves I'm afraid but an initial small trial surely can't hurt and you never know till you give it a try.

After all there isn't a commercial treatment for onion white rot and we are told it is untreatable. But there is now a growing body of evidence that spreading pulverized alliums (onion, garlic etc) on the onion bed a few months in advance of planting the onion crop reduces white rot noticeably.

Likewise it is against EU regs to use soapy water to control aphids. But nothing to say you can't wash your plants and if a few aphids succumb, well, it's just collateral damage.

[Vinlander]

Obviously the best natural pesticides are things that work despite the fact that we can eat them - garlic etc.

Oxalic acid does come under this category in small doses - a) there's no way it will ever get into the plant itself and b) if it's on the surface and you are daft enough to eat it soon after treatment then you can taste it. Don't use it on spinachy stuff as you might not notice!

However there are also a few things we have a strong (almost paradoxical) resistance to and bugs don't - you may have noticed a lot of people taking lots in as smoke and living long enough to get ill from just about everything else in the smoke  except the nicotine.

Cheers.

[Robert_Brenchley]

The vast majority of the nicotine is burnt up. Even an addict can kill themselves quite easily if they start eating their fags!

[lottie lou]

Ah, but what wouldn't I give for a f*g :(