Plumhill, I agree with your basic premise, but I don't think a comparison of Cu vs. Sevin is a very good example to make your point. Sevin is more dangerous than Cu. I am certainly not a syntheti-phobe and many times grow weary of the public perception of organic vs. synthetic pesticides. Namely, the unfortunate public opinion that organic is always better than synthetic. Certainly the LD50 value is dependent upon the particular formulation of Copper and the particular formulation of Sevin. I have both Copper and Sevin in my lockers and their LD50 values are as follows: Kocide 3000 has an LD50 of 1847 mg/kg and Sevin 4F has an LD50 of 590 mg/kg. A little bit more Kocide is required for a full dilute spray vs. a full dilute of Sevin but even in full dilute, Sevin is more acutely toxic. There are other health considerations besides acute toxicity as well. This in my opinion is where Sevin loses the race. It is a cholinesterase inhibitor and listed as a carcinogen and developmental/reproductive toxin for mammals. Cholinesterase inhibition is the big deal here. I've read some applicators who routinely spray carbamates (i.e. Sevin) or organophosphates periodically have their cholinesterase levels checked because of the risk associated with these compounds. Again these risks are for applicators who are spraying these compounds all the time, not for a homeowner occasionally spraying their fruit trees, or applying a little Sevin dust to their vegetables. I'm not trying to make anyone paranoid about Sevin or copper. I'm not afraid to use either one, but from a health standpoint, I'd rather have repeated exposure of Cu vs. Sevin. From an environmental standpoint, I'd rather spray Sevin because, as you point out, it breaks down quickly. There are plenty examples of synthetics out there that are safer than Cu. Many of them have LD50 values of greater than 5000 mg/kg. Scott mentioned MFF. I see it has an ld50 of 4340 mg/kg. That means the concentrate of MFF is less acutely toxic than table salt. Quite safe.

I'm posting on this OLD post because it still comes up at the top of google search for "citrus peels lower soil ph" ... I have been doing tests with Citrus Peels.... I have found that about 30 good size grapefruit peels blended up in a blender (lots of batches of blending) with half water/half citrus in the end, produces a good acid base. I did enough to fill 30% of a 5 gallon bucket, which I then diluted to a full 5 gallons of liquid. This was then diluted 5 fold to register a drop in pH of 1 for the water... This diluted citric acid can be used similarly to sulfuric acid dilute. There is a company here that sells Moon Juice which is a combination of sulfuric acid + iron and other trace minerals... It's used for temporarily lowering the ph so trees and shrubs and such can uptake iron and other minerals that lock out at alkaline pH Levels... Given that we're in the southwest we have an ABUNDAND supply of citrus and over time, this is the same effect the trees fruit would give to the soil if there were no humans to tend to and pick the fruit... the fruit would rot on the ground, the citric acid would leach out into the ground as it decomposes and maintain a more acidic soil balance for the trees long term support... So can you use citric acid to dilute, yes you can, though, just like with a sulfuric acid dilute, you're going to need to apply it regularly (monthly or so depending on ph plant/etc) until the bacteria that feed on the sulfur have had enough time to lower the soils actual ph levels ... Something that seems to be long forgotten as I read some of these posts is... all living things have a pH, you can burn things by dropping ph too fast, or by raising too fast, so obviously some of the responses regarding putting acid next to the roots are appropriate, they are also inappropriate because your obviously not going to dump straight acid on anything unless your intention is to utilize the full strength of the acid :P Good Luck! Would love to hear about what you've done and how it's developed since your original questions!

t-bird, surgery is 1/31. On the list: Everything! (But we've painted most of what has to be painted, so my job, unlike yours, is just getting rid of stuff and cleaning every surface, like an old-fashioned spring cleaning.) We're empty-nesters so there are no kids' rooms to clean or kids to give attention and time to. Kitchen is about 90% done, foyer (only a little coat closet and some tile and the front door) is done. Workout room was just painted and is finished except for the closet, which is full of old political-campaign paraphernalia I need to box up or get rid of, and I don't really care much if I get to that or not. Downstairs too is my office, which is a sea of papers, and a TV room and guest bath. Upstairs I have the LR, dining area, and MB, along with 1 1/2 baths. So I may be able to get all of this done. I move very slowly because of my knee, so it takes a while. I'm not going to stress about it; whatever I get done will be better than what it was before I started. Storage area in basement and garage will probably wait until later. I'll join you in a 2012 cleanup project. Mine will be to finish up whatever I haven't done, if anything, before I go to the hospital, and then to keep things in order. I'm the messy one and DH is very neat. Good luck to both of us, t-bird. And may we enjoy the process!

why are you putting water retaining mulch ... on succulents??? you are over watering.. as you admit.. and supporting some vermin in the wet soil ... bugs dont affect children ... its not an issue you need growing hints in the cacti and succulent forum .... provide pix of your plants .... and i am sure.. one of these wizards will recognize the worms ... i am thinking fungus gnat larvae ... and that means you are way to wet .... see link ken Here is a link that might be useful: link