Appropriate use of pesticides is to treat only after you have a problem.

Spraying preventive insecticides is an outdated practice. It doesn't work.

You do need to treat PM before it shows up...but things like insecticidal soaps don't do any good unless there's bugs for it work on because it's mostly a contact insecticide.

It gets into grey area with something like neem oil because it can be used for some things as a preventative measure and many other things as something you use once the pests show up.

BT can be preventative, but for the most part it depends on the pest and/or if the pest is laying eggs during that time of season. Scouting for problems and then applying can be just as effective in many cases as constantly reapplying it. If you apply BT when there's no activity and it just washes off with the rain, then it's not doing much preventative work. Myself, if I had a constant problem issue which could be controlled by BT, I would apply only when I spot pests during the growth phase of a crop as needed...and if the crop was super-important I maybe would apply it as an "ahead of the game" preventative while it was fruiting (or when the moths start swarming in the case of greens in my area).

Spraying things like Neem and Insecticidal Soaps, which are broad spectrum poisons, as preventinves does much more harm then good because you are killing off any beneficials that might help control the pests. Organic groweers only spray poisons if other methods of control do not work, not as a profilactic measure.

For prevention, I like to pick the insects and prevent the mildew with dry, airy sunlight.
Last year however, I couldn't possibly pick enough 'harlequin Looking' bug that was destroying my 4 climbing cucumbers. A preventive spray may have been useful there, becuz once the problem started, I lost. :)

Worm Tea....

Worm Tea, is a new one on me. Is this worm castings or some kind of worm that you make juice from?

Mapler:
I haven't tried it yet, but supposedly it's like compost tea but made with worm castings. I just might give it a shot this year -- I've recently read that castings are not only great for the soil, but for pest deterrent also.

Experts: what's your opinion?

Kevin

"Experts: what's your opinion?"

It increases the activity of the beneficial microorganisms that live on the surface of the leaves.

And Yes, your right, "Experts" do have quite a bit of "opinions".....
;)

This post was edited by TheMasterGardener1 on Thu, Jan 31, 13 at 0:03

The poster's question was about pests and diseases, so I'm assuming that the worm tea and the microbes it populates the leaves with, actually is helpful for diseases? Are chewing bugs also deterred? :)

IMO, worm tea is such a rich source of nutrient/microbal quality that spraying it on leaves rather than applying it directly to the soil is a bit of a waste of an otherwise great amendment.

Maplerbirch:

I'm not sure. Though I'm well aware of worm castings being like gold as an amendment, I still haven't gotten around to adding it to my regimen. I've heard that applications of castings are a deterrent to a great number of pests -- even whitefly and aphids, which aren't necessarily chewers, but suckers.

Yes, Worm Tea builds up the micro activity on the surface of plants leaves when misted over the plant. This will help stop/prevent both plant pests and plant disease.

I prefer warm tea as it is having natural rich source of nutrient. Organic products are the best to get better and long term benefits.

Here is a link that might be useful: Organic Farming

Teas made from compost or worm castings may be of some help in growing plants that are somewhat healthier and better able to ward off plant diseases and insect pests. Little of anything I have found indicates teas made from worm castings are any more effective are pest control then plain water although there is much verbage out there, primarily from people selling worm teas, touting the insect repellant properties of teas made from worm castings. One of those sources states that worms teas kills off the microbes which of it does can be detrimental.
The best method of control of insect pests and plant diseases is to make the soil those plants grow in into a good, healthy soil with a soil pH in the range the plant likes and a balanced amount of nutrients in the soil so the plants grow up strong and healthy.

Well I've tried just about all the other great ideas for gardeners over the years, I guess doing one more isn't going to hurt.
Someday we might be able to put together a book of all the "Simple Gardening Tricks" that never worked.
Thanks for the input, and I'll try to remember to report my findings next summer, including Potato Bugs as well. :)

No need to write it:
"The Truth About Garden Remedies" from Jeff Gilman. In this book he tests out garden remedies/rumors/treatments from beer over compost to soda, regular fertilizer, vinegar, soaps ect...

If you can call 1-sq-ft plots tests... That guy completely unimpresses me, and he admits his "research" is intended to find a particular conclusion, so no doubt he thinks he does.

Wow, thanks for all the replies and debate which definitely made me think twice about what and when to spray. Really, the only thing I sprayed consistently was a neem oil mixture on my plants because the year before I found all my leaves got eaten and by the time I used the neem it was too late as it takes awhile to work unlike something like Pyrethrin. I've actually read that neem doesn't kill off the beneficial insects because those are no munching on the leaves of the plants. It seemed to help a lot more than harm my plants so I will probably use it this coming year as part of my routine, heck, it even rid my house of fungus gnats by spraying the soil and leaves of the indoor plants which somehow got infested even though I sterilized everything. Maybe it was that pointsettia my girlfriend gave me :). From what I gather on this post I guess spraying baking soda as a regular regimen isn't the way to go about preventing powdery mildew or mosiac virus so I'll have to rethink my ideas and keep a close eye on things. I really wasn't intending to soak my plants with pesticides regularly but my thoughts were if they needed to be sprayed and I also wanted to say foliar feed them with some liquid fish emulsion or seaweed would there be any hard in combining the ingredients and the answer here I guess is quite possibly so I'll avoid any mixtures.

Thanks again to everyone for all the help,

Rob

Rob: Not sure if baking soda works for PM or not. All I know is that NOTHING works if symptoms are already visible-- so, in the case of PM, I think a PREVENTATIVE is necessary. Because what I found out is you have to treat for PM PRIOR to symptoms.

For example, if you know your squash gets PM EVERY year around the same month when the heat and humidity rises, then maybe it would be wise to start treating for it about a month before then. Whether baking soda, neem, milk, or Serenade, etc.

"They" say that full sunshine and air circulation helps with PM. I say bull.

Kevin

Any pesticide has the potential of doing harm to many insects, including beneficials. While Neem Oil products have low toxicity to beneficials, although rated to be of medium toxicity to bees, there is still the potential it can harm them because like all poisons it does not know whether it should kill them or not. Perhaps the link below might shed some light on this.
I have used Baking Soda sprays to stop powdery mildew many times with good results as well as milk sprays.

Here is a link that might be useful: Neem oil

This post was edited by kimmsr on Wed, Feb 6, 13 at 11:37

I believe the idea for using worm tea foliar spray is the film left on the leaves is unattractive to pests. I raise my own worm castings which is what the tea is made from. It also helps to deter mildew spores from settling on the leaves . So far this season only a brief bout with aphids on honeysuckle but no mildew as of today.