Pests in the Garden: How to fight them without Pesticides

While our gardens are full of bad insects that bite us and eat our plants, many of the bugs in our garden are not only helpful and beneficial but responsible for much of the food we eat. Many of our valuable pollinators are on the decline due to habitat loss and overuse of pesticides by both commercial farmers and home gardeners. Since pesticides cannot tell the difference between a good bug and a bad one, it is best to not use them at all. 

Yet, insects like aphids, Japanese beetles, and squash bugs can destroy a plant quickly. And fleas, ticks, and mosquitoes? In addition to those itchy bites, they carry diseases which can be fatal. What can we do? It depends on the insect really.

Here in our garden, we use a variety of different methods for insect control. We have chickens, ducks, and guineas that roam free-range throughout the day eating every bug they see. Since introducing chickens to our garden, we have seen a significant decrease in Japanese Beetle damage. Guineas love to eat ticks, I am told. And ducks just eat every bug within reach. Since I have read that geese eat snails, I am entertaining the thought of getting a goose for my garden. (Don’t tell my husband.)

Aphids will usually be taken care of by Ladybugs, if you haven’t killed them all with pesticides. If you don’t have a good Ladybug population, you can order them online from Gardens Alive. Be sure to follow their instructions when you release them. Its really the Ladybug larva that devours the most aphids.

If you can’t wait for the Ladybugs to do their job, use the safest insecticide you can, insecticidal soap. You can purchase it ready made or make your own (1 or 2 Tablespoons of pure liquid soap like Castile, not detergent, to 1 quart of water.) Spray on the undersides of leaves and only where you see aphids.

For Japanese Beetles, mix up a cup of soapy water and add a little vegetable oil. Take it outside and as you see a Japanese Beetle, knock it into the soapy water. The oil will prevent its being able to climb out. This is a good job for your little boy, if you have one.

For many plant pests like squash bugs and tomato hornworms, the best method of control is to simply pick them off by hand. Since I don’t like to touch bugs and caterpillars, I use my pruners to knock them off. You can then mash them, or if you have chickens, knock the bug on the ground for them to fight over. It’s been years since I’ve seen a grasshopper in the garden here. Our chickens used to fight over them. It was fun to watch.

For ticks and fleas, here is an excellent recipe for homemade repellent.

Planarian: Eater of Earthworms and Enemy of the Garden

When rearranging containers at the greenhouse recently, I ran across something unusually icky–a planarian. 

Land Planarian

Planaria are non-parasitic flatworms existing in most parts of the world. Some live in ponds, while others are terrestrial and can be found under flower pots or in other moist places. You’ve probably seen a planarian before, but might have mistaken it for a slimier than usual earthworm. 

A land planarian is long, flat, and either gray or brown with several black stripes running the length of the body. A planarian can be extremely long. I have seem them almost a foot in length. And, once again, this creature is not native to Georgia, but is thought to be originally from China. 

Planarians have been found in the United States since about 1901. Planarians just love greenhouses, because they provide everything a planarian needs to survive: moisture, humidity, and something to eat. Planarians appear to be dispersed with plants–we might unknowingly bring one home  in a plant we purchased. 

Planarians have a mouth that also serves as an anus. How gross is that?! 

Where might you find a planarian? They like places that are dark and moist, so look beneath container plants, boards, or rocks. If you’re lucky enough to experience a heavy rain, they might even be seen on the soil surface, especially under shrubs. If you have a worm bed, look for a planarian attached to an earthworm.

High humidity is vital to the survival of a planarian, and they are seen most often in spring and fall. 

Planarians move about by gliding on a stream of mucus, and if they find themselves up on the leaves of a plant, they can lower themselves using a stream of that mucus. Yuk! They leave a shiny slime trail like that of a snail. You might be thinking, yes, this is grossly interesting, but what does all this have to do with gardening?

Planarians are cannibals and will eat each other. They will also eat slugs, which could be a help to the gardener. Perhaps this is the grossest fact yet–a planarian can even use some of its own tissue for food if necessary.

But what concerns me is that planarians eat earthworms! The earthworm is a gardener’s good friend, and I want to protect all my earthworms. A planarian infestation is devastating to a worm bed and reportedly is capable of destroying the earthworm population of an entire farm. 

I won’t describe how the planarian turns the earthworm into food, because that’s even more yucky than what I’ve written so far. 

You should not try to destroy this pest by mashing it, since it will regrow from small parts of itself. So if you chop up a planarian, you’ll be multiplying it. In the past I’ve just tossed them into the garbage can, but experts recommend melting them with a spray of orange oil.