Ants ew! Ew! Ew! Hate ants in the garden.. Evil little things. They say that they don't actually harm your plants but I've noticed that stuff that gets invaded with 'em tends to get crispy pretty quick. Maybe because I don't tend to them as much as I should because I don't want to deal with the ants!!!
Anyway -- can you get grits there or are they still a strictly Southern thing?
Grits are our sure-fire natural no-chemical ant killer down here. Not instant grits.. real cooking grits. Sprinkle them where the ants are most obvious like you would any bait... and wait. Apparently the ants like the taste but can't digest them before they expand in their little insect abdomens or something. All I know is it works... takes about 3 days to see the ant mounds deserted.
As for the daisies and such... have you mulched? No mulch can lead to scorched roots... but!! mulch too close to the base of the plants -- and the roots can't breathe and will be essentially strangled to death.