I just came back from my raised bed garden and am afraid to return. The concrete blocks are full of chiggers!
I've had some terrible experiences with chiggers and don't want to weed or pick lettuce until the chiggers are dead. What is the best way to kill them without getting my vegetables full of poisonous sprays or powders?
Chiggers are the larval stage of harvest mites and are microscopic so you wouldn't be seeing them. Are they ticks? I know some people get them confused. But if what you are seeing are the adult mites, than the larval chigger is definitely around (the adults are harmless).
Regular insect repellant actually helps a lot. So does sulfur. You can dust your shoes, socks and ankles with it. But for some reason it doesn't work on ticks. You just get yellow ticks sucking on your blood!
As far as an application to the area, I don't know much that isn't going to be terribly toxic. I think diazinon is recommended for chiggers. All the organic stuff leaves no residue, so you will only kill the ones that are there at that moment. But it would help control the population and give you a respite for harvesting!
Good luck - chiggers are awful (I'm actually dealing with quite a few bites myself right now)!
I just had an exterminator come through my office. He said what I saw were spider mites. They bite, but don't cause the intense itch of a chigger.
I told him I sprayed them with a mix of dilluted dish soap, listerine, and ammonia. It killed the ones I sprayed, but others just ran over the sprayed area after it was dry. If anyone else wants to know, he said to use diluted laundry soap with borax to kill them.
That makes more sense than Chiggers. The spider mites are really hard on your plants also. They suck the juices from the leaves. You'll see the leaves yellow and a pattern develop along the veins of the leaf and if you look closely you will find the webs (that's why they call them Spider Mites).
The more you kill before they start on the plants the better.
There are several commercial miticides that can be used early in the season to kill mites.
Pyrethrum has been used to kill mites. It is a natural pesticide produced by a close relative of the chrysanthemum. The problem with using it is that many races of mites have developed immunity to it. However, it is the first miticide you should try.
Cinnamite comes as a concentrate that is diluted and sprayed on the plants. It contains a miticide derived from cinnamon oil. It is very safe and is rated least hazardous. It is quite effective but it doesn't kill the eggs. It should be used every three days for two weeks to make sure all the mites are killed soon after they hatch. It is a contact spray so plants should be dipped or sprayed on the leaf undersides. It is also effective against powdery mildew.
Neem oil is a natural miticide derived from the nuts of the Neem tree, which is found in India. It is a mite repellent as well, so some gardeners use it as a prophylactic, spraying it on a weekly basis. I mix neem oil with Cinnamite to eliminate small infections. Cinnamite and neem oil are also used against powdery mildew.
For growers who distrust anything commercial, try an herbal tea that acts as a miticide. To each quart of water use a tablespoon each of ground cinnamon, ground clove and 2 tablespoons of ground Italian seasoning. Heat the mixture until it starts to simmer, then turn off the heat. Add 2 tablespoons crushed fresh garlic when the water cools to warm. Let the tea sit until it cools. Strain and save the water using a cloth or coffee filter. Add a few drops of liquid soap or dishwashing liquid to the water. It is ready to be sprayed on the leaf undersides. After spraying the mites off with water, spray it on the leaf undersides. It will eliminate the mites if it is sprayed every three days after the wash. Within two weeks the mites will probably be gone.
Avid is a miticide registered for ornamental plants. Its active ingredient is abamectin, a derivative of a toxin originally found in soil bacteria. Avid is not registered for use on vegetables except in certain restricted situations. Other brands of abamectin such as AgriMek by Syngenta are registered for a wide range of crops. The AgriMek label calls for a minimum of a seven day wait between application and harvest. I wouldn't use marijuana if I knew it was treated with this pesticide during the last few weeks of flowering.
Some gardeners have reported success controlling mites using predatory mites or other predators. These carnivorous mites reach an equilibrium with the herbivorous mites, keeping damage to a bare minimum. I have tried introducing mixed species of predatory mites a few times but have never been satisfied with the results. They did not get the problem under control. However, they can work and some gardeners swear by them. I probably didn't provide them with the right conditions. There are also other predators that eat mites, but I have no experience using them.
Ultimately, the solution to the mite problem and the pest problem in general is to prevent the garden from becoming infected. Following certain simple rules will help:
Wear freshly washed clothes or change into a garden outfit when going into the garden.
Never work outdoors, especially in a garden or other vegetative or turf area right before working in your indoor garden.
Pests are frequently carried in on shoes. Do like Mr. Rogers and change your footwear before you enter the garden.
Don't use outdoor soil, tools or containers in the indoor garden
If a plant is to be introduced to the garden, first do a close examination and then put it in quarantine for five or six days. Examine it closely, especially the underside of leaves, before placing it in the garden.
Close up any unfiltered airways or holes through which plant pests might enter. Make sure that air intake from outside is filtered.
Back to chiggers, with which I am very familiar on my place, here are some suggestions that work for me:
1.) If you want to be all natural about it, just be sure that you immediately wash off using lots of soap and a washcloth after your day is over. That will prevent all but a very few bites. I make it a regular practice to shower and scrub everywhere after each day out in the pastures.
2.) If you want to further reduce your chances of itching from any bites you did get, take your favorite antihistamine after you get out of the shower.
3.) If you are like me and must sometimes be where it is heavily chigger-infested and you will have lots of contact with plants and grass, and you don't think there's much wrong with DEET (which has been in use since WW II), the best thing I have found is Backwoods OFF. Spray around your pants leg bottoms, shoes, beltline, and on upper arms if you are wearing a short sleeve shirt or t-shirt. It doesn't take a heavy application. You still have to wash after you come back in, but it helps a lot in keeping them off you in the first place when doing chores that will guarantee contact, or when picking blackberries, etc. Often, you can stay totally bite-free using a DEET product like Backwoods OFF.
Sweetpea Farms "To avoid criticism, say nothing, do nothing, be nothing." -- Robert Gates
Chiggers and ticks are everywhere here. Impossible to kill all of them. Having been walking the fenceline for the past few weeks repairing the problem spots, my legs are covered with bites right now. I just use ChiggerX to get rid of the itching. In the garden I will try the recommendations posted by peter nap (thank you , I copied those), and also hve about 5 pounds of DE left to dust with.