For those of you that were not at the organic pest control class this past month, I have provided abbreviated notes. As always, send an email or respond to the post with questions.
There are a number of ways to ensure that your crops thrive during the growing season and avoid falling prey to damaging insects. Some of them include:
* Improve the health of your plants
* Use a barrier such as a “floating” row cover (covered by Bill Yoder in his gardening class)
* Remove insect intruders by hand
* Repel insects with a strong smelling oil such as clove, thyme or garlic
* Plant companion plants and trap crops
* Use biological controls
* Use organic pesticides
Improve Health of Plants
It is important that transplants and especially young plants get regular water in order to build strong roots and thrive, especially during periods of low rainfall. Dry plants can become stressed and attract insect pests. Sickly plants, much like sickly animals in a wild herd of African antelope, are the first to succumb to predators.
At the same time, over watering can present fungus issues and attract slugs, but if this year is anything like the last several in Atlanta, we will be unlikely to face overly moist conditions.
One of the best supplements for growing plants is a foiliar spray of liquid kelp. Spray the leaves of plants in the early morning to regularly supplement healthy plants growth.
Remove Insects by Hand / Spray with Water
If you can, keep a daily eye on your plants. Look under leaves for your eggs and hiding insects. Soft bodied insects such as aphids can be sprayed off of plants with a burst of water from a simple spray bottle. Larger insects can be picked and dropped in a cup of soapy water to finish them off (and who likes squishing bugs anyway?). Be sure and look under rocks and large pieces of mulch for hiding insects. But leave black beetles alone – they eat lots of bad bugs.
Prevention / Repellants
I like to use Green Light Organic Insect Control Concentrate which was purchased at Farmerd’s. This formula is made from thyme oil, sesame oil and clove oil. There are many other types of repellants that people have used over the years. The theory is that strong smelling oils can confuse attacking insects. Others believe the strong smell simply drives away would-be habitants.
Repellants are NOT good to control infestations but should be an initial “preemptive” insect control program. Regular application will work to repel and control infestations. Insects are going to be visiting your garden. Repelling the unwanted guests is a great way to keep down the potential for a full-on invasion.
The Green light repellent concentrate is something I like to call “almost vegan-friendly” in that it repels without killing. But some bugs may be terminated in the process so we should probably just stick with calling it organic. Some controlled insects include pillbugs, caterpillars, earwigs, aphids and whiteflies.
Beneficial Insects and Plants / Companion Planting
Attracting beneficial insects such as Ladybugs, Green Lacewings and Parasitic Wasps are a great way to keep damaging insects at bay. The following are some recommended beneficial plants that can be planted in our around the garden.
* French marigolds repel bad nematodes / scent confuses predator insects
* Parasitic wasps feed on nectar from fennel and small flowered herbs
* Radishes repel squash pests
* Yarrow attracts parasitic wasps
* Evening primrose attracts ground beetles
* Basil – repels mites and aphids / plant near tomatoes for tomato hornworm control
* Horseradish planted with potatoes repels colorado potato beetles
* Use radish & nasturtium for cucumber beetle control. Nasturtium is also for trap crop of aphids and to deter squash bugs
Beneficial Nematodes kill eggs and adults of grubs, fleas and vine borer grub, among others. Bacillus thuringiensis (or Bt) is a soil-dwelling bacterium that kills chewing worms such as caterpillars, tomato hornworm and loopers but does not harm people, pets, beneficials or earthworms.
BT comes in both a powder form as well as a liquid. Dipel dust contains BT an is available at any garden center that sells organic products. This stuff is really smelly but works well.
Insecticides & Fungicides.
Neem oil is a versatile garden solution that can repel insects, kill insects and also provide fungus and mold protection. Neem is a great broad-spectrum pest control that works when repellants are insufficient. It is also one of the few organic fungicidal options.
The choices for organic insecticides has grown tremendously as the popularity of organic gardening has spread to community gardens, urban farmers and backyard gardeners.
One of the best ways to control cutworms, slugs, snails, pillbugs and other crawling creatures is Sluggo (comprised mostly of iron phosphate). If you have ever picked up a slug, it is quite difficult to wash off the slime they leave on your fingers. Sluggo makes it easy to control slugs and snails without having to make a mess.
When all other methods have failed and you have a full blown infestations, Pyrethrins are a best last resort. Pyrethrins are broad spectrum and can kill almost any adult insect and their eggs. The problem with pyrethrins is that it can kill beneficials as well, so be very thoughtful about when and where you apply pyrethrins.
Organic does not mean “harmless” by any means so please remember to wear gloves when handling any of these products.
If you need help identifying bugs or want to learn more about properly applying insect controls, send an email or comment on this post.