I don't think the toads are hurting your flowers. Its probably some sort of tiny insect. Lots of my flowers aren't doing so well this year. They seem to have lots of leaf problems. If anything, the toads are probably trying to keep down the insect population.

Catherine is right. Toads are really a gardners friend as they eat the bugs.

Well guess what...I initially would have been right up there with the other two posts, but I was helping my mom plant flowers yesterday and she mentioned this very thing. I'd never thought of it, and it is a possibility, although easily remedied.
Last year she had some geraniums in a pot on the back deck next to the pool and noticed that they were looking horrible. She checked them out and realized they were loose in the pot and when she started poking around in the dirt to tamp them down, three toads made a dash for it. When she told me this, I realized that they had simply been doing what toads do, which is search out mulch or loose dirt, someplace cool to hide out during the day's heat. They start with their rump and legs, scooting and shuffling further into their chosen site until they have made a hollowed-out spot just right for their body. Sometimes they will be completely covered with only an eye or two visible, like a little flounder or something. The potting soil in mom's geranium planter was always slightly damp and somewhat fluffy...perfect for a toad to root around in and wait for night to arrive. They do it in my mulched areas all the time but there's nothing here with new or fragile roots that might get damaged.
That's the only way I can possibly think of where having toads might be a setback. Before putting the blame of them, though, look carefully in the soil around your plants to see if there are any hiding there, or look for their vacant hollowed out areas with fairly smooth interiors. . They might be any size, depending on the "tenant". Toads seem to know their way home and will return to a site again and again if they find it to their liking. If you do find them there, gently remove them and fill in the cavity they made, and then try to exclude them from returning. Despite anything they may have done to the roots of your plant, they truly are your best friend in the garden. Is there a similar place in your garden with shade and loose dirt/mulch or things to hide under where they would be more welcome?

should have read your post more thoroughly...sounds like you already know about toads and toad abodes without any long-winded sermon from myself.....

and this is in perennials??

Now I'm not so sure that it might be toads after all. Just check to see if they are loose.

DG, That makes sense. I had never thought of them digging aroudn the roots. To avoid this, do you think it might be helpful to add a small place for them to go like an upturned broken plantpot to hide under?

Dirtgirl, I enjoyed your "sermon".

A ring of chickenwire with cutouts for the plants and then covered up with a thin layer of mulch would deter toads digging in the flowerpots. I would just worry about the toads hurting themselves in the attempt to rearend themselves in. Ouch.

Think the brown spots more due to extreme amount of moisture. Plant leaves not allowed to dry out are more subject to fungi and rot or leaf burn from hot sun on wet leaves.

I check our pots everyday and remove them when I find them. Every pot they stay in for any extended period of time kills the plant. I believe it’s their poisonous urine.

what can I put in the pots that will repel them?

I am suffering the same nightmare from these toads! Though we have a hard clay soil we have amended it with looser soil where we plant our annuals, perennials, or shrubs and they have killed a number of them by excavating holes down around their roots (even completely dislodging one newly planted flower). It does make me wonder about the toxicity of their urine as well. As for now I am also ”over these toads” - and their destruction.