Caffeine is a natural insectide, if you are a coffee plant. I've never tried making a coffee spray, and it would have the obvious downside of staining the plant. I just thought I would point out the natural purpose of our favorite natural buzz...

The recipe above would definately work, but it has a lot of redundant ingredients. Alcohol and soap should be sufficient to suffocate all the adult mealies. Listerene is an interesting 'natural' ingredient. Use only the organic non-GMO kind ;-)

Brad

I have a few more fungus gnats than desired on one or two of my indoor plants - currently debating whether I am going to go with BT (Bacillus thuringiensis) or a sundew plant. BT is a natural insecticide that sold commonly in stores.

A sundew plant would probably cost about the same as the insecticide, but has the bonus of being interesting and 'reusable'? If I can keep it healthy/alive. I've never owned a carnivorous plant before.

What is FE?

Many of the active ingredients in your homemade spray are also in insecticides found in stores. Just that they do not contain 'extra' ingredients that do not assist in killing the pests. One example would be scent in the soap and sugar in the mouthwash.

Dish soap is in insecticidal soap and helps wetting. Capsaicin is a natural insecticide and miticide (probably not in stores before because it can be painful to your eyes!). Alcohol (Rubbing and Listerine) is commonly used as an insecticide. Lemon Oil and Eucalyptus Oil (Listerine) are also natual insecticides and often included in those found in stores. Polysulfide (Garlic) is pretty much the same as that found in Neem Oil, which is sold itself as a pesticide.

As mentioned above, tobacco is carcinogenic and staining, so at least we should make sure what's natural won't harm ourselves in the process. That includes chili peppers too. As long as you keep towards scientifically proven ingredients, you can keep the snake oil out of your spray.

To be honest, most commonly used pesticides are natural. Humans aren't so good at developing new chemicals for insecticides - it's much easier for companies to find things that work very well in nature and extract or synthesize those compounds.

Of course, it is a good debate on how far you need to go for something that is 'natural'!

@Ewwmayo, I believe FE is Fish Emulsion. So if your plant wasn't funny smelling before, it sure will now. Thanks for breaking down the ingredients, that helps me to see things a bit more clearly. For sure, no one wants to be duped by some snake oil claim, there is a lot of that out there, but if you can back things up ^^ with proof then it makes sense to use.

Yeah Im iffy about the Tobacco as well guys, even though some growers have been using it for decades. I grow a fair amount of orchids and TMV is rampant, so its probably best I stay away from this and start up even more problems.

While I understand Listerine isn't as "natural" as some of the other ingredients but it has extracts of menthol, eucalyptus, wintergreen, and thyme oils.

My thought process is, if I was growing outdoors exclusively, and knew using X (insert name of whatever bug killer ) wouldn't harm bees/other beneficial pollinators/bugs, I'd have no objection to using it. Growing indoors is difficult, and I don't want to harm or potentially harm any pets, family members, etc by using it. Everyone's growing needs/environments are different so I can understand there are people on both ends of the spectrum when it comes to insecticides.

What are the insects and/or diseases that you have to fight most often?

Some could be decreased or perhaps even eliminate by eliminating environment they like most - like fungus gnats..they love moist and organic environment.

Others are much more difficult. I use a q-tip dipped in rubbing alcohol or spray of r. alcohol+water if I see any scale or mealy bugs or aphids. Another good practice is to check plants frequently and if there is anything, try to get rid of ASAP.

Many oils are available to purchase, and solutions could be made easily. I did make a spray from ground cinnamon, but it is much easier to make it with the oil!

Carnivorous plants are definitely interesting. A friend who successfully grew Venus Fly Traps told me most people kill them by using tap water. He only used distilled water and had much success. One thing to investigate before starting your bog involves the use of peat. I read somewhere that some people have strong skin or respiratory issues with this media. It may be just another urban myth like the hysterical reaction to Euphorbia sap. Like all things, some people will in fact have bad reactions to a particular irritant while most others just need to use care in handling. I wonder if the fungus gnats might actually like the peat environment?

I use FE use on occasion as a fertilizer/ feeder, in a short time the flies hoover around the soil line and foliage for a few days. It's not that flies are harmful as they're not a pest but the things they carry with them could be.

My next door neighbor uses coffee to treat aphids. It does not work! So I have to treat more heavily with soap/alcohol/water mix to treat my plants since his stay heavily impacted and his aphids visit my plants. In all fairness, maybe he uses decaf, because I know he doesn't drink regular coffee. So maybe that doesn't work.

A little off topic, but I had to share.

I vote at Rotary Park here in Cape Coral, FL. It is a total eco park with plant and animal sanctuaries. Beautiful place, actually, and I am lucky enough to be within walking distance. On election day in 2012 we had huge lines winding through the foilage areas to the main building where voting was taking place. Unfortunately, a newby groundskeeper who apparently had no idea that voting was occurring soon at this facility treated the entire area with FE the day before election day. UGH!! Standing in line we had to endure the stench of rotten fish!! Trust me - November in Florida is still warm enough that it was really a suffocating experience.

While FE may be great for our plants, it really is not a pleasant experience when standing for hours in an eco park. And yes - it made us all wish we had brought bug repellent with us! LOL

Haha fish emulsion is bad. My dog wants to dig in the soil of my pots for a couple of days- perfume to him. What's the purpose of it in an insecticide?

@Rina I've had to deal with springtails a bit, they seem to magically find their way to my plants, not sure if they do any harm, but their presence makes me uncomfortable. I dont have this problem yet *knock on wood* but would like to be prepared just incase I get slammed with mealies. Im getting ready to order a number of plants and from what I've read online they're very very mealy prone, so yeah :/.... Very interesting that you mention cinnamon, does it burn the plants at all, have you used it with no ill effects?...

@nomen_nudum, I've read online that FE is great in cases of scale, but I dont know... How long do you find that the smell lingers for?

@Crenda hahahaha I bet thats something you'll never forget. I can only imagine with the heat and humidity of Florida, that the smell was amplified.... Ugh...

@Breathnez it seems that it is used for scale, but I dont know for sure. My understanding is that it was a 'natural' fertilizer with lots of good micronutrients, dont know beneficial it is to cacti/succulents!

Minty

Springtails are 'good bugs', you'll find zillions of them in compost (leaf litter, moss, a ny decaying material...) - they don't directly participate in decomposition of organic matter. They control microbial communities, and help in decomposition by fragmenting organic matter - so I would think that there are suitable conditions around for them to appear. They prefer moist environment. I read that they consume spores of some fungi - so that would be beneficial? I should do some more reading about them...

If you buy new plants, best practice would be to keep them isolated from other plants, carefully inspect for any signs of insects or diseases. If you find anything, treat the plant away from others. Many nasties could be brought home from stores.

I use powdered cinnamon on large cuts (usually jades-they have thickest trunks). Just apply a small amount over the cut area, it is considered antifungal. Just a small amount is needed. I used spray on the leaves of phaleonopsis that had fungus - while the leaves eventually died off (took a while) there wasn't any fungus spread on other leaves and new growth. I also used it on aloe that seems to have some kind of fungal disease - I couldn't find any info, so just sprayed it. It's been a while, and so far it looks like that spread of fungus stopped; damaged areas dried and I cut them off (they were completely dry). Rest of the leaves seems to be fine. I never had any burning or similar problems, only that it will leave little stain. But stains I cleaned off within few days disappeared. And plants smell good (if you like cinnamon!)

As anything else, use in moderation. Someone mentioned that cinnamon powder would interfere with new growth - I don't know for sure since I didn't notice. I don't see need to use it on smaller cuts (thinner branches), and so far didn't use it on other succulents but jades.

I never used FE for anything. For scale, q-tip dipped in alcohol works great (or spray as I already mentioned).

Does a synthetic derived from chrysanthemums count as natural?

Best organic insecticide us spiders, hands down. Chicken come in a close second. They get more bugs than spiders but the spiders can live IN your plants and not eat the plant. Chickens love vegetables.

If derived from plants directly, yes. It is also manufactured and combined with some other synthetics, and not considered organic. Synthetic pyrethroids are considered toxic especially to fish and cats. They are also used combined (pyrethrin and pyrethroids). Bees are sensitive to pyrethrin in very small doses, so it is advised to apply at night, and as a spray rather than dust/powder.

My choice insecticides/fungicides include cinnamon for fungus, BT for fungus gnats (it works like a charm - and you can buy bricks of the dehydrated bacterium for pennies) and neem oil for everything else. If there's a really big problem, I'll dilute a natural pyrethrin emulsion and lightly spray that on. All of these are plant-derived, aside from the bacillus thuringiensis.

I only use it in the house because it affects spiders too.

I use it on the dogs and chickens (and in the coop, mtes are the worst!).

I don't kill house spiders - they catch flies...