They look like they need water but then they die.
It sounds like there is something going on with the soils. If the soils moisture is kept good they should be doing fine. Sometimes in strings of hot days the soils moisture gets depleted very quickly and the plants can get cooked pretty quickly. This scene that you describe can also be due to our dog or cat friends using the area as their toilet room. Or can be caused by something sprayed nearby that drifts over onto other plants unintentionally. It can also be caused by folks pouring out their drink or some other liquid upon the soils the plants are in or nearby that then leaches into the rot zone of the plants. I would keep an eye on your garden area and see if any of these issues reveal themselves. I have seen cases where a lawn care firm sprayed the neighboring lawn with something that drifted over onto an entire garden next door and killed the plants. They are licensed applicators and should not be letting this happen but unfortunately they do from time to time.
The flowers have been turning black. And the other issue is the leaves have started turning kind of yellowish with spots. We can't seem to find anything that matches our problems. We hope you can help. Thank You
Marigolds are generally resistant to pests and issues, but this sounds like a fungus problem.
Remove the black and diseased parts of the plant and dispose of and treat the plants with Neem OIl. I would use weekly until the plants improve.
https://www.gardeningknowhow.com/ornamental/flowers/desert-marigold/growing-desert-marigolds.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
I have lymphoma cancer and sprouts help me do much better. Do Marigolds sprout and can you eat them? In the past, I grew sprouts and used them in salads, sandwiches and any way I could and was much healthier for it. Can Marigolds be eaten as sprouts also? I was told they are great to keep from going blind along with peaches, red peppers, sweet potatoes, and I was hoping to keep my sight or improve it.
I found this article that may have information on the consumption of Marigolds you may find interesting.
http://www.motherearthnews.com/organic-gardening/marigold-uses-zmaz83jazshe
Where can I buy edible (organic) Marigold seeds and/or plants?
Organic seeds are becoming more readily available.
I would first check you local garden centers.
If your not able to locally purchase, just do a Google search for organic seeds.
There are many sources that can ship to you.
Do Marigolds really work to keep rodents and other animals out of a garden?
Marigolds can help deter pests in the garden.
They will not work to keep rodents or other animals from your garden.
https://www.gardeningknowhow.com/ornamental/flowers/marigold/marigold-companion-plants.htm
This is my first year doing flowers for our condo association, I know I'm planting marigolds since they will look good into fall, what is another good choice to use as a backdrop to them?
There are so many choices!
Visit your local garden centers and look for interesting and colors that please your eye!
This article has more information.
Hi, I just planted some marigolds today. You said that the plant should be covered with plastic wrap. My mom says that's going to kill the plant. Is that true. Could you please tell me what are the advantages of covering it with plastic wrap? Also, when I planted my marigolds, they were right next to each other. I know it's too close, but will it kill them plant?Thanks!
If you are starting Marigold seeds, it is appropriate to cover the planting tray with a plastic cover or plastic wrap to keep the seeds moist-until germination.
https://www.gardeningknowhow.com/ornamental/flowers/marigold/growing-marigold-flowers.htm
If you planted Marigold plants you should not wrap your plants with plastic.
Marigold plants should be placed 12 inches apart, they will spread and fill in quite quickly.