Ant Control

I'm looking for ways to get ants out of the garden. Parts of the garden have become nesting havens. I've looked around the net to find remedies. But I'd like to know what actually works.
The best potential solutions have included Tansy, Southernwood, and pepper. One person even suggested using ground dried banana peels. There's even a concoction of (I think) boric acid and sugar being used as a bait. Somebody else even suggested oregano, lavender, or lemon oil.
What works? Are there other things? Ideally, I'd like to plant things in places around the garden and be able to control the ants. But other solutions are not out of the question, as long as they won't kill other things in the garden.
By the way, I am also interested in finding non-chemical ways to keep them from invading the house. Again,

I have heard of tansy, but it must be fresh to work and I don't think it works as a planted plant. I had it for years in front of my window and ants were still plentiful in the bed they grew in. I did manage to use cut fresh tansy to repel them from my kitchen counter, but had to replace it once every second day with fresh material to keep it effective.
Boric acid powder mixed with sugar and water into a paste works as a bait. To repel them from a kitchen use fresh lemon rinds, put where you last saw them. Renew when they get mouldy. They last much longer than tansy and seem to be very effective. I would think that lemon oil would work just as well. I think it interferes with their reading of their scent trails.