DIY neem spray

20130316-133232.jpgHere is our super easy and super-effective homemade insecticide recipe!

Gather your materials

Bucket Neem seeds Pepper Chili powder Garlic Cinnamon

Blend with a splash of water. Pour into your bucket and add water.

Ferment for a day or so.

Strain and spray on pest-sensitive crops. No need to spray willy-nilly. Just use it where it's really needed, or you risk killing beneficials.

It's best to spray in the morning or evening because the hot sun will break down the molecules, decreasing its efficacy.

We spray this often, like every day or so and have seen a huge improvement! Read our post on using grow cloth and soap sprays for more on our pest battles!

Grow cloth

20130315-061440.jpg It is time to revisit the topic of whiteflies. At the beginning of the season we were overwhelmed with whiteflies. We used soap to try and deter them because it is the gentlest pesticide I know of. You can read about that struggle here .

It didn't really work. They managed to destroy multiple plantings of tomatoes and green beans.

However I'm happy to report that things are looking up! We have a two-pronged strategy: grow cloth to keep them out of very sensitive crops (green beans and an experimental tomato tunnel), and neem sprayed on everything else.

Ok, I know I really knocked neem back in my November post, but after talking to Kathy, our local Gardening Guru , it may not be as harmful as I thought. Kathy says that industrially produced neem doesn't break down as quickly as the organic stuff. That means the neem pesticide we make ourselves won't kill as many beneficial predators as I assumed.

At any rate, the plants are happy! They are so green and glowing after our frequent neem sprayings, I'm starting to wonder if they are also being fertilized by the minerals in the neem!

Our green beans and tomatoes under grow cloth are beautiful and the tunneled tomatoes have set fruit before the control group (no grow cloth, but did receive neem sprayings). You can see here that the beans under the tunnel are much taller than the beans in front. The uncovered beans are still disease-free, most likely due to neem spraying.


Stay tuned for our recipe for DIY neem spray.

Organic pesticides

Whiteflies are attacking our green beans and tomatoes and squash. In a perfect gardening world, our soil would be so rich that the plants would be so healthy that the whiteflies wouldn't be interested. Just like lions attack the weak and the young buffaloes, pests attack weak plants. We would also have a thriving perennial flower garden around and amongst our vegetable crops which would provide habitat, shelter, and nectar for beneficial predators like wasps and ladybugs. Alas, our garden is a work in progress and outside inputs are necessary. Spraying insecticides, even organic ones, can be counterproductive. Think about the ratio between predators and prey. Usually one habitat supports many prey animals for just a few predators. The rate of reproduction is also much faster among the prey animals. So you spray and knock out half of the pests and also half of the predators. The problem is that the pests will now reproduce faster than the predators. In a week, your garden may now have the same amount of pests as before with only half of the beneficial predators.

Just because something is natural or organic doesn't mean you can use it indiscriminately. There are always unwanted side effects! Neem oil is much-touted but is definitely my least favorite. It stays in the body of the pest and if a predator eats the pest it will kill the predator as well! Yikes!

Insecticidal soap is a popular method for dealing with whiteflys and aphids. It has to come into contact with the insect in the moment and works by dissolving the insect's exoskeleton. We use soap everyday without thinking, but it turns out it is very dangerous for insects. You can use any real soap, not detergent, but most experts recommend using Safer's Insecticidal soap, or some other commercial brand, because it is specially formulated at the right concentration to not burn or damage your plants. Many home gardeners recommend using Dr. Bronner's Peppermint soap, diluted at 1 tsp to a liter. The peppermint oil will also act as a repellent when you're done spraying, whereas most soap is only effective in the moment! A soap spray that drys on the leaf and is eaten by an insect later is no longer effective; it has to be sprayed on the insect's body.

So, with a heavy heart I sprayed my beans and my tomatoes and my squash with Dr. Bronner's lavender soap (because that's what I happen to have). A moment too late I saw a ladybug; she will certainly not make it. I checked under the leaves, hoping to spray the eggs, and saw a spider. My good hard-working friend! I left her unsprayed. I also found many aphid lions which, you guessed it, eat aphids, and managed to shoo them away before spraying my death ray.

We will see how the struggle plays out in the days to come!