I've had a terrible time here in L.A.- zone 10- with powdery mildew - this time it got my squash, cucumbers, tomatoes and bush beans; now it's working on my pumpkins. I have tried a bunch of things - milk, baking soda and a little detergent, etc.- but they seem not to work. Realize I probably water too late in the day and put manure on at the wrong time...but still! Most sites states that "treating the soil" is not useful, but one site says to cover with clear plastic and let it sit for 4-6 weeks - longer if it's rainy. Seems like a long time to wait - but I'd do anything to fix this problem! Can anyone help? Another thing - I'm from the South and can't help but notice how much better plants like melons, okra, summer squashes do there. I'd attribute this to it nearly always dropping down to the 50's and 60's at night, instead of staying hot. Am I the only one that thinks this?

Digging up this old post in the hopes the OP sees it and can update with product used and what degree of success, or anyone else with updated info. As OP stated info online is conflicting at best. We have 3 cypress porches around our house, decking with hidden fasteners and T&G ceilings, Douglas fir posts.. We have had no issue with mold/mildew on any of the ceilings. The decking and posts however have been a disaster, posts almost black, decking not quite as bad but bad. We are in western NC mountains at the edge of a temperate rain forest. Decks and posts were treated at install with Penofin Red Label Clear - seemed like a great idea at the time. Ceilings were treated with Australian timber Oil Clear but I don't know if it's the product that has kept them mold/mildew free or because they don't get wet like the decks and posts. We scrubbed decks and posts last weekend with a detergent/TSP/bleach mix, then power washed with clear water. Decks look great, posts are significantly better, might need another round. Do we use the Australian Timber Oil and hope it works as well as it has on the ceilings? Research has turned up some people saying that oil products actually give the mold/mildew something to feed on and acrylic products are better. There's not a lot of info out there for cypress but it's still a rabbit hole. Leaving them untreated is not an option given our climate. They need some protection from water and significant southern sun. If anyone has specific product recommendations I'd appreciate it. We have some unused boards and can test if need be.

Well, it is winter now, but there were no scales nor any other pests visible until the end of the season. I realize very well that the 'IPM book' says to first ID the pest then apply the specific treatment for that specific pest (and for the specific plant), that would be easy. But there is no pest ID since there were no pests visible. Sometimes, one can indirectly ID the pest from the specific damage done to the specific plant, but as I said in the OP, there was no damage visible either. One could say, no pest visible, no damage visible, hence no treatment is indicated ... but not so fast ... ... the ants and bees kept coming to the plant until the end of the season ... one could say that treatment is very well indicated ... but non-specific treatment can do more harm than good, what is the worst harm ... or the non-specific treatment can be merely ineffective ... or very effective in the best case ... The facts have been given in the OP, the info is unfortunately incomplete for the reasons explained and will remain incomplete (it is winter now) when the best time comes for applying dormant oil (this coming April or May around here, depending on weather) ... given the incomplete info, the question is to treat or not to treat?

In a solution with a ph greater than 7 (soapy water) the electrode potential difference between stainless steel and aluminum results in galvanic corrossion. Clean water rinses help to extend the life of the spider (the sacrificial anode), but changing the spider to stainless (best option), or passivating the aluminum with an alodine coating are better approaches. The question becomes: do I spend $500 on a new drum/spider (the Frigidaire spider/shaft cannot be purchased separately), plus $100 to passivate the spider, or apply that money to a new commercial machine with a stainless spider (e.g. Maytag, Speed Queen). . . ?