I don't use organic methods for disease control but someone will probably recommend baking soda. For inorganic methods, Walmart sells Daconil, about $12 a bottle. I use it on my tomatoes, pumpkins, corn, etc. I haven't grown cukes in a couple years, otherwise would use it on them too. Mark

Homebody, your suspicion about bacterial wilt is probably correct, if you have cucumber beetle problems. You should also inspect the stem of any dying squash vines, to see if squash vine borers are responsible. If you find their larvae, or the holes left by them, then prevention next year is your best hope for success. And if your "white aphid looking creatures" look like this, then you should try to kill them before they reach adulthood. The symptoms of squash bug infestation can appear very much like bacterial wilt. Butternut squashes (Cucurbita moschata) are more resistant to beetles & borers than C. pepo (pumpkins & summer squashes) and C. maxima (buttercup, hubbard, banana squash). I quit growing zucchini for that reason, and now grow Tromboncino (a butternut relative) instead. It has few problems... but it does take up a bit of space, unless trellised. You can protect young squash plants with floating row cover, until they either blossom, or outgrow it. This gives the plants time to build up strength, so they have a fighting chance. For me, this prevents SVB, and by delaying the start of attack, reduces the population of cucumber beetles & squash bugs. I could not grow most winter squash successfully without the use of row covers - I highly recommend their use. The use of nylons or some other impenetrable wrap (around the base of the squash stem) can prevent the SVB moth from laying their eggs there. Also, try to grow squash varieties that root at the nodes; bury the stems early, to encourage early rooting... this will help the plants to survive, if SVB does kill the main stem. The last thing that you should do (after killing the squash bug nymphs) is to eliminate any pests that might otherwise over-winter. SVB pupae lay dormant underground, so a Fall tilling will kill many of them. Cleaning up any debris in or near the garden will help to reduce the population of squash bugs the following year.

There are two categories of plant diseases that affect plants. “Abiotic” diseases have no pathogen, and are generally caused by any of a number of cultural factors. Since there is no pathogen, abiotic diseases are not infectious. Cultural factors like light, temperature, soil chemistry/soil structure, media air:water ratios, air pollution, pesticide/herbicide residue, insect herbivory, ….. can individually or collectively cause abiotic diseases, or, even though not infectious, set the stage for “biotic diseases”, which involve living pathogens. In this case, the OP asks about the infectious/fungal/microbial pathogen, powdery mildew. Fungi are the most common pathogen affecting plants in our gardens, but bacterial and viral pathogens are sometimes players, too (even though there's a question re whether of not viral particles are living OR microbes – not really applicable to this topic). Plant pathologists often describe the disease process using a 4-sided figure called the disease tetrahedron (think “pyramid – 3 sides + the bottom). Each side of the tetrahedron represents an essential part of the infection process. There must be a virulent pathogen (capable of infecting the plant) which is genetically capable of recognizing its host. Either the environment must be conducive to the development of the pathogen, or the pathogen must be able to stress/weaken the plant. The 4th requirement is the time required for diseases to develop and spread. Whenever conditions are such that any one (or more) of the 4 requirements is missing from the equation, there is no immediate threat. Since the best medicines are prophylactic, the grower who makes sure plants are healthy and not stressed is ahead of the game. Biotic diseases are better able to overcome the natural defenses of plants weakened by stress that occurs when the plant is forced to deal with cultural conditions near or beyond the limits the plant is genetically programmed to deal with. These would be plants not growing in the light, temperature, soil, fertility, ....., "sweet spot". Circling back to the disease tetrahedron, we can see compost that contains the virulent inoculum provides 2 of the 4 essential sides needed for a disease to develop – environment and inoculum. Time, the third essential side will not likely be on the side of the grower, so you can't use that to your advantage. We know there will be potential hosts (it'sa garden!), but not whether the hosts will be susceptible to the pathogen, or weak enough for the pathogen to infect the host. When you start to analyze, it doesn't make a lot of sense to take the position you'll build the size of your compost heap at any cost. Al

I'm trying to wrap my mind in tightly sealed plastic so the disease organisms don't escape... or is it to prevent contamination? A conventional farmer who tightly seals diseased plant debris in plastic is not much of a farmer. I know a few farmers...did I say a few? They would till the plant debris in (some would use a prescribed burn, depending on situations), and use crop rotation...for instance, if you grow potatoes, you don't grow potatoes on the same field year after year. You grow potatoes on any given field one year in five, or even more. In the other years of the rotation, you grow wheat, corn, alfalfa...crops that are not affected by the same diseases that bother potatoes. Sanitation, resistance, and crop rotation. Conventional or organic may not be as far different as some would have you believe. I'll repeat my statement. The first thing you learn about organic growing is sanitation. The second thing you learn is sanitation. The third thing you learn is how many pesticides are used. In the part of the world where I currently live, the organic growers do mare spraying than the non-organic growers. The next thing you learn is that people tend to think that they are the only ones who know how to grow organic, because everyone else is brainwashed by (insert mind controlling organization here. I prefer the Spectre of Ian Fleming's works, because that make me a horticultural Bond, James Bond). If you are the only one who knows what organic growing is, then the rest of the world can only be wrong. I find that position to be...untenable? about compost management and disposal of diseased plant parts.. So there's this thing about compost, heat, and biological organisms. For any given temperature, there's a given length of time that will cause the organism to be killed. At 180 degrees F, this is pretty short. at 140 degrees, this is a bit longer. Even at 120 degrees F, there's a given time, but it's longer yet. When it comes to backyard gardens and managing disease, it's usually easier to say, dispose. the caveats are, what's the disease problem, how long do you let your compost sit and at what temperature. There are a couple of diseases where the best answer is, get rid of it. Fire works very well in this regard. However, we also live in world where local ordinances can sometimes be...exasperating? I currently live in a town where composting is specifically prohibited. The town doesn't enforce this, unless someone complains, but composting is specifically prohibited. Fire codes are such that a backyard fire pit could be prohibited entirely. Some might say silly, but we live in a world with a lot of people. How many of them would you trust with a match? So how does one provide an answer of how to deal with diseased material, when there are unknowns as to legal environment of the person asking the question, nature of disease organism, and how the compost pile is managed by the person asking the question? You tend to default answers. Composting early blight contaminated plants is different than plants contaminated with powdery mildew, mostly because the danger posed by the disease is different. Peas and cukes are easily replanted and still get a yield that season...much harder with tomatoes. Even harder with orchard crops. Yes, different diseases affect these plants, to varying degrees, but people like simple answers. So the simple across board answers become the default, when the full answer requires a lot of time to get across...and most people just don't have the time to do that with every person who asks the question.