Organic pest controls that work well

If you're planning on growing zucchinis in a humid spot such as Sydney, your plants will develop powdery mildew this summer as sure as there will be tennis and cricket on TV then, too. And if you grow fruit, including tomatoes, then fruit fly are certain to pay a visit. Now, while 'live and let live' has its merits with some garden visitors (such as caterpillars which turn into butterflies), ignore powdery mildew on zucchinis and it's a case of 'live and let die', and with fruit fly it's like this: either they get the crop, or we do. They don't like sharing, and for that matter nor do we.

The good news is that organic pest control methods are getting better all the time, and I thought I'd post away merrily about three organic methods that even the non-believers ought to start believing in. First up, controlling powdery mildew using milk...

Here's the zucchini patch this morning. Mostly healthy leaves and lots of flowers and fruits developing, but on the left of this photo you can see some leaves with powdery mildew. Me, worried? Not when there's milk in the fridge!

Perfectly well named is powdery mildew. Looks like white powder, and with our recent bout of soggy and humid weather it was a certainty to show up here. It hasn't affected all leaves, just some, and the reason it hasn't spread much is the milky spray. This spray doesn't kill off the mildew altogether, but it does slow its spread to a crawl.

The formula is as simple as can be. One part milk to nine parts water. I mix up a batch in a measuring jug, then apply via this 500ml spray bottle. As I have only three zucchini plants, this is more than enough. You can use any milk you like: skim, full-cream, buttermilk, low-fat, whatever. And if you don't use all the solution one day, just give it a good shake a few days later and you can use it again. The experts say skim milk is probably best, as it has the least fat and so doesn't smell much at all.

As mentioned above, the spray slows down the spread of the disease, rather than eradicates it. The important thing is that cropping isn't affected at all. We're harvesting often. The downsides of this spray are that that you have to re-apply it every time it rains, and every five or so days anyway. But with my small crop that really is just a three-minute job.

If you belong to the non-believers about organic controls, this milk spray has plenty of academic backing. Here are two links to articles on the topic. It was discovered by an academic in Brazil originally, and is now in use in a wide variety of agricultural industries, with plenty of research assistance from local universities.

http://www.thefrugallife.com/mildew.html

http://www.abc.net.au/science/news/stories/2002/667732.htm

This next 'organic' pest control method still has me a bit worried, but I thought I'd include it in the hope that someone reading this blog might enlighten me. It's called a 'Sticky Trap' and it's made by Bugs for Bugs in Queensland (a company which also sells predatory beneficial insects such as mites which hunt mites, wasps which hunt garden insect pests, etc). This yellow one is labelled as attracting and catching 'aphids, whitefly and other flying insects'.

This is the blue sticky trap from Bugs for Bugs, and it controls 'thrips and other flying insects'. Apparently the colour lures particular bugs, and the extremely sticky coating on the trap does the rest.

The problem I have with these traps is they seem to do a lot of business in the "other flying insect" category. The other day I noticed that one of the yellow traps had snared a ladybird, so I do have some doubt about these traps. I do know that Bugs for Bugs has a great reputation for its expertise with supplying the predatory garden insects, but from a lay-person's point of view these little traps look the insect equivalent of the killing fields. Anyone who could enlighten me about them, please let me know!

The third organic pest control product featured here is all-new to me, but it comes with a lot of very encouraging publicity, plus full organic certification by BFA, one of the Organic Certification Bodies. It's name is Eco-Naturalure, but I thought I'd get down to basics and show you that it really is black, sticky, sweet-smelling goop.

This is a small 150ml jar of the stuff, and that cost $21.96 at Bunnings (our resident monster hardware store chain), so it's not cheap (although the 1-litre bottle, at around $50 is better value – I just couldn't afford it!). And it's not easy to apply, either. The instructions say to mix up 10ml in 60ml of water. Lacking either a 10ml measure or a 60ml measure, I improvised and discovered that the little plastic scoop that came with my tub of Dynamic Lifter holds 70ml, which was a lucky find.

In fact the instructions that come with the Eco-Naturalure must be read beforehand, or it probably won't work for you. As well as being precise in mixing it up (and the thick gloop isn't that easy to handle) you need to:

1. apply it to one square metre of foliage to protect 50 square metres in your backyard. (In my little backyard which is 9m x 7.5m, I opted to spray two patches, just to be sure, as neighbours both sides grow fruit, and I figure that fruit flies don't recognise Anglo-Saxon property law.).

2. Use up the batch you mixed up, and don't keep it. You also have to rinse out the spray bottle afterwards.

3. Avoid repeat-spraying the same spot again. This is because repeated use of the product on foliage can lead to sooty mould developing on foliage.

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4. Re-apply once a week

5. Re-apply after rain

6. Avoid spraying sensitive fruit such as pears, mangoes (not a prob for me, not growing them)

7. To get around problems with repeatedly spraying foliage, they recommend spraying a piece of plywood and hanging that in the tree. The plywood would need to be cleaned before re-applying the next batch. And the spray concentration used on the plywood is different from that used in a foliar application.

How the stuff works is that it uses a natural insecticide called Spinosad (which is based on a soil-borne bacteria). Here's a link to the manufacturer's website if you want to read more. And it's actually very important to read all the stuff at the website about how to apply it, how not to apply it, etc. I made a few mistakes early on and have learned a lot in the first few weeks.

http://www.ecooroganicgarden.com.au

All the repeat sprays after rain, etc, is almost par for the course for most organic pest controls. Many of them work very well, but many of them are also hard work. If you get into a routine of doing the same bunch of jobs every week in the garden, and you make the organic spraying part of that weekly round of tasks, then it becomes remarkably easy to mix up a batch of milk spray or fruit fly spray, then spend a minute or so doing the job while you're out there. Doing it as a routine works better than spraying only when you notice a problem, because by the time you notice the problem it's probably too late.

It seems that there's some top quality research going into developing organic solutions for common gardening pests, diseases and problems. The tradition that everything about organic gardening is home-made and has a farmyard simplicity about it will just have to make a bit of room for the next generation of organic gardening – the one based on good science. As far as I'm concerned it's the best thing that has happened to gardening in a long time. Organic gardeners have set the agenda for the future of gardening and finally, finally, science has got the hint and is catching up fast!