Sprinkle spent coffee ground where you have ants since they hate the coffee grounds. I had a lot of problems with ants this year. It was water that was attracting them to my garden. They were walking up the garden hose in droves. So with the help of the coffee grounds and vinegar, I was able to get rid of them,
There are two different plants that are called "marigold". So knowing which one you planted might help.
One plant that many people call marigold is pot marigold, Calendula officinalis. As far as I know, they will not help with pests.
Usually, strong-smelling plants help deter pests.
The marigold, tagetes is very strong smelling.
I also like to plant sweet alyssum, Lobularia maritima. It is very fragrant and has a sweet smell.
Invasive plants are Earth's way of insisting we notice her medicines. Stephen Herrod Buhner
Everyone learns what works by learning what doesn't work. Stephen Herrod Buhner
Yes, Calendula is great for many skin conditions and for diaper rash too.
Its oil is safe to use on children and it has great smell.
I make my own infused oil of it, it's very simple.
Basically you just need to grind the dried flowers and soak them in carrier oil, like sweet almonds cold-pressed oil, for 3 weeks, then strain it and that's it.
the ratio of the calendula and the oil should be 1:20