Insect repellent is a ‘fact of life, it’s needed for any plant you will ever grow whether indoors or outdoors. Unfortunately, the really toxic chemical-based repellents are the most effective…that is if you wish to leave toxic waste all-around your plants to be absorbed by them and eventually eaten by you.
There are some organic alternative repellents that you can buy or make yourself. I would suggest making them yourself because once the label ‘organic’ is applied to any product, the price seems to go up by 50%.
I use the term ‘organic’ very loosely here because the key ingredient of many of the following recipes is dish soap which is certainly not organic so the term ‘organic’ is used here to distinguish from a harsh and toxic chemical.
So how do some of these insect repellents work?
I am not really sure of how they work but I do know that they are effective as repellents and even as killers of insects. I do know that soap will cut through the natural oils of a small soft insect body and help water completely enclose the insect drowning it.
Soap will also penetrate the insect cell walls and halt respiration. The problem with a soap-based insect repellent is that it is ineffective as soon as it dries on the plant leaves and too much can actually damage the plant being helped…
Here are some recipes, most of which can be mixed, poured into a spray bottle, and sprayed on a plant to apply:
| 1 cup tobacco 1 gallon water Soak tobacco in water for 24 hours to make a weak tea then strain.This will kill caterpillars, aphids and some worms but do not use on solanceous plants such as tomatoes, peppers and eggplant. Also hazardous to humans. |
3 Tablespoons liquid detergent 1 gallon water Kills slugs. Use weekly |
| 1/2 cup alcohol (rubbing or the drinking kind)3 Tablespoons dry laundry soap
1 quart warm water Do not store – make new for each use. Kills mealy bugs. Mix and spray when needed |
2 Tablespoons salt 1 quart warm water Kills cabbage worms and spider mites – mix and spray as needed |
| Spray flying bugs with hairspray Maybe not the most organic of repellents but it does work. It stiffens bug wings the same as it stiffens hair. |
Leave a small container filled with beer at the plant base. If the container is buried up to the lip of the container, slugs will crawl in and drown. |
| 5 Tablespoons of soap 1 gallon water This is homemade insecticidal soap with soap at a 1% to 2 % concentration. |
1 small piece of cardboard, index card size vaseline Color the card yellow and coat the surface with vaseline. If placed somewhat level with the top of the plant, flying bugs will be caught in this homemade sticky trap. |
| Chamomille tea made according to directions Chamomille tea is a natural anti-fungal and anti bacterial substance so instead of drinking it, spray it on plants with powdery mildew and damping off |
Neem oil added to the homemade insecticidal spray (mentioned above) Neem oil is a natural pesticide. |
| 1/2 cup chopped hot peppers2 Tablespoons soap
2 cups water Widely used and very effective repellent (also can be used as homemade mace to be used for defense) |
1 package chewing tobacco1 ounce listerine1 teaspoon dish soap
1 gallon water Not very organic and extremely toxic; do not touch, inhale or drink! |
| Broken eggshells sprinkled around the base of plants Slugs will not cross over a line of eggshells. |
Toothpicks buried until only 1 inch is sticking up around a plant base Will keep small animals away. |
| 1 Tablespoon canola oil1 Tablespoon baking soda3 Tablespoons Tabasco6 drops dish soap
1 quart water Very effective… |
Dryer cloths stuck on sticks and placed next to plants Not organic but will keep deer away. |
| 1 bulb garlic1 onion1 Tablespoon cayenne powder1 Tablespoon liquid dish soap
1 quart water I like this one the best! |
1/2 cup dead bugs 1 pint waterChop dead bugs and slugs in a blender and add to water.Organic, yesPleasant, no Effective, extremely. |
As you can see the basic insect repellent recipe comes in many variations and not all are adaptable to hydroponic use. But remember that due to the nature of hydroponics, you will never have many of these bug problems; notably slugs.
Organic pest control using ‘Parasitoids’ is a fascinating topic. These are a group of insects that are born, grow up and feed upon a host insect. They can literally spend their entire lives inside of another organism.
Unlike true parasites, parasitoids kill their host rather than just taking nutrient from it and coexisting side-by-side. Just think in terms of the movie ‘Aliens’, if you have seen it, where an alien creature gestates inside of a human host until it bloodily springs forth killing the human host in the process.
If introduced to your garden these insects are extremely effective; so effective, in fact, that they will give the term ‘organic pest control’ new meaning!
The popular selling parasitoids are mainly small, stingless parasitic wasps, generally 1/4 inch long (6 mm), who lay eggs inside of another insect, hatch and feast. Here is a list of some of the more popular varieties used as organic pest control:
| Parasitoid | Description |
|---|---|
| Encarsia Formosa | This tiny parasitic wasp has been used as organic pest control around the world since the 1920’s. It goes after whiteflies and is used mainly on the whiteflies that attack tomatoes and cucumbers. Sold as eggs, 1 egg per square foot of garden works best to be repeated every 2 weeks for 4 times. |
| Trichogramma Minutum | Extremely small parasitic wasps (5 fit on the head of a pin) that attack caterpillars. Very popular with small growers, they attack cutworms, tomato hornworms, corn earworms, codling moths, fruitworms, cabbageworms, armyworms, cabbage loopers, corn borers, webworms, and cane borers by laying their eggs inside of moth eggs preventing the caterpillar from emerging. They are sold as strips of paper containing 5000 already parasitized moth eggs. Hang the paper near the caterpillar infestation and it is all over for the caterpillars. |
| Aphidius Colemani Aphidius Matricariae |
The entire Aphidius group consist of small parasitoid wasps that love aphids. They are sold as already parasitized aphid mummies which will hatch wasps. The adult female wasp will seek out and parasitize an aphid by following distress signals from plants. Generally 10 eggs per square foot of garden works best for organic pest control to be repeated every week for 3 times. |
| Diglyphus Isaea Dacnusa Sibirica |
Small (2mm) parasitoid wasps that attack leafminers. The female wasp seeks out leafminer larvae and lays her eggs next to or within the larvae. The small wasp hatches and feeds upon the larvae. One female can parasitize up to 360 leafminer larvae. They are generally sold as pre-hatched, pre-fed adults and released at a rate of 58 per square foot, every 2 weeks for 3 releases. The Diglyphus Isaea species is adapted for summer and warm climates while Dacnusa Sibirica is adapted for colder climates and even winter. |
| Pediobius Foveolatus | Parasitoid wasps who parasitize the Mexican Bean Beetle (pictured here). They are sold as parasitized Mexican Bean Beetle mummies in ‘units’ where 1 unit contains 20 bean beetle mummies and approximately 500 wasps. One unit covers 2 square feet. These wasps should be released when the weather is calm and there are yellow beetle eggs present. When the wasps hatch they will immediately find and parasitize the beetle eggs. |
| Aphytis Melinus | These parasitic wasps feast on scale. They are shipped as adults and once established the females will search out scale larvae and lay their eggs in it. When the wasp hatches it will consume the host. 1 to 2 wasps will control 1 square foot of the garden and must be released weekly for 3 intervals. |
| Eretmocerus | Another parasitoid wasp native to desert areas and favoring all kinds of whitefly. It is shipped as eggs packed in bran and these eggs can be spread around the base of plants to hatch in a couple of days. When releasing be careful that ants do not take the eggs away. The female wasp lays it’s eggs next to whitefly larvae and when they hatch the baby wasps spend 3 to 4 days burrowing into a whitefly nymph. After they enter the nymph they become dormant until the whitefly pupates and then they release digestive fluid to start dissolving the whitefly. |
These parasitoid wasps do their job but are not cheap to buy. None will survive winter with the exception of Dacnusa Sibirica and, in fact, many will die within a couple of weeks or simply leave when the food supply runs out.
They are usually shipped out overnight or 2nd day and when received, can be stored in the refrigerator for 2 to 3 days before use. Storing in a freezer will kill them.
There are beneficial insects and there are nuisance insects in your garden. The nuisance bug will eat your plant or somehow suck the life out of it while propagating madly and the beneficial or ‘helpful’ insect is there to help you out.
Beneficial insects are the fighting troops of your army that will destroy the invading army of nuisance insects. These ‘good’ insects have really never been used in gardens until recently.
They are the bugs that eradicate your problem pests for you without the use of any kind of repellent or pesticide. More and more hydroponic stores are offering pre-packaged, live bugs that you can release into your garden as a completely natural and organic means of gettings rid of garden pests.
A number of years ago I was introduced to these ‘good’ insects in a rather novel way… My wife and I own sea kayaks and we have kayaked several of the large lakes all through the northeastern USA.
There is nothing more pleasant than cruising the shore of a lake listening to the birds and searching out a remote spot for a picnic. Except… when the deer flies start buzzing you looking to take a chunk out of your hide.
And as you go further north the deer flies are replaced by moose flies which are several times larger and meaner. When a moose fly bites, it hurts!
Predatory insects can now be purchased online in most hydroponic retail shops. You can buy full grown insects or eggs to hatch these insects.
Once you get them in the mail, release them according to the instructions and sit back while your army attacks the invaders…
Are there drawbacks to this approach? Yes.
- The price of these beneficial insects seems rather high to me,
- Once released, it may take weeks before the insects ‘take hold’ – maybe too long,
- When the pests are eradicated, the predatory insects, that you spent good money on, will probably move somewhere else where there is food,
- Introducing insect species into certain areas may upset the natural environmental balance (something to keep in mind).
When these flies appear our response was automatic; paddle as fast and as far as possible from these little devils.
One day, as a deer fly attacked me, I noticed a dragonfly land on the bow of the kayak and my first thought was that another pest had come for the feast!
As the dragonfly began to buzz me I realized he was not ‘buzzing’ me at all, he was buzzing the deer fly. I watched as he chased the deer fly around and around, circling him like a helicopter.
Then when the dragonfly reached a good position he launched himself at the deer fly, clamped on and took off holding onto the deer fly for a feast of his own.
This was when I first realized that there were beneficial insects as well as problem ones…
The same goes for your hydroponics, and even ‘dirt’, garden. Do not discount how valuable a ‘good’ insect could be to your garden; it could literally save it from an insect predator…
I have looked at different online hydroponics stores and am amazed at how popular buying these insects can be; at one site I counted over 25 insect varieties for sale. And keep in mind that there are ways to attract ‘good’ insects and birds to your garden without spending the money buying them.
So what exactly do these insects do for you? What are the varieties of species?
I have divided these predatory bugs into 3 separate categories – and these are solely my own categories not someone else’s. And they are not all insects as you will see…
First are the parasitoids, a personal favorite of mine, next are the nematodes, and lastly, are the rest of the insects.