Is there a soil best suited for growing wildflower seeds planted in containers ?
They will, usually, do well in just about any soil! Wildflowers are hardy and adaptable, so don't worry about getting the soil perfect.
Here is an article that will help:
https://www.gardeningknowhow.com/ornamental/flowers/fgen/container-grown-wildflowers.htm
our site is very helpful. love it!
These articles should help. First you need to remove the grass and rocks. You can solarize to kill the grass or apply a product containing glyphosate.
https://www.gardeningknowhow.com/ornamental/flowers/fgen/planting-wildflowers.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-9-10-11/choosing-wildflowers-for-zone-9.htm
https://www.gardeningknowhow.com/plant-problems/weeds/how-to-kill-grass-naturally-kill-unwanted-grass-in-your-yard.htm
I live out in the forest up around Newport Washington and around my house is natural wildflowers and then I also have a marsh behind my house closer to my house I've been watering the the plants to keep a green zone for fire protection etc but at the same time we have a lot of really beautiful naturally established wildflowers and I'm wondering with this heat and such how often and what part of the day can I be out there giving them help with extra water thank you very much
Native plants shouldn't need irrigation, but since you are having a heat wave, they might need some extra help. Try to water in the early morning before the sun hits them, and make sure they all get a good soaking, even if you need to run a soaker hose there.
Here's an article: https://www.gardeningknowhow.com/garden-how-to/info/watering-during-heat-waves.htm
I have sterilized (or killed off) my old crabgrass infested lawn. It's under black plastic and ready to be rolled, leveled, and planted w/SOMETHING. I live in northeastern Oregon in a semi-arid area. The area is mostly full sun and has some slope.
We have just the articles to get you going!
https://www.gardeningknowhow.com/lawn-care/lawn-substitutes/lagen/growing-flowering-lawns.htm
https://www.gardeningknowhow.com/lawn-care/lawn-substitutes/lagen/wildlife-garden-turf.htm
https://www.gardeningknowhow.com/special/spaces/fall-meadow-maintenance.htm
https://www.gardeningknowhow.com/special/spaces/a-wildflower-garden-in-your-backyard.htm
https://www.gardeningknowhow.com/lawn-care/lawn-substitutes/lagen
You have relatively mild winters, so you can plant at just about any time. I do recommend spring, but it won't hurt to sown in fall. Here is an article that will help you to get started:
https://www.gardeningknowhow.com/ornamental/flowers/fgen/planting-wildflowers.htm
Can wildflowers be grown in an indoor hydroponic system?
It is certainly worth a try. You will probably need supplemental lighting. These articles should help:
https://extension.arizona.edu/sites/extension.arizona.edu/files/attachment/WWSummer2020.pdf
https://www.gardeningknowhow.com/special/containers/deep-water-culture-for-plants.htm
https://www.gardeningknowhow.com/special/spaces/a-wildflower-garden-in-your-backyard.htm