I have been gardening for years and have usually good luck starting plants,...
I have been gardening for years and have usually good luck starting plants, this year hardly any luck, I have tried green onions, cauliflower, tomatoes, nothing seems to germinate, I have tried compost, planting mix, hmmm the only thing in common now is basically water, but I have used the tap water before, Suggestions Please, new seeds, good brands, hmmmm
Have you done anything differently than in prior years?
You mention planting mix, does that mean you are starting seeds indoors? If so are you using a sterile mix? Is it a seeding mix? A brand name? If so, check the composition. Brooke Edmund's (from Oregon State) recipe for pasteurized medium for growing seedlings is a mixture of one-third pasteurized soil or compost, one-third sand, vermiculite or perlite, and one-third peat moss. Here is a link http://extension.oregonstate.edu/gardening/2016/01/set-seeds-right-path-homemade-soil-mixture
Are you watering with water straight from the pond? Is the pond treated with anything? The water could be contaminated with some kind or organism. Try going back to tap water or use distilled or boiled room-temperature water.
If you are seeding outdoors have you checked the soil temperature? I including a link to "Growing Your Own" another OSU publication which includes a planting date chart for vegetable on page 7. It is a great, though long, publication. https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9027.pdf
I hope these resources fill your need. If not, please let me know about answers to the questions above and we can take it from there.