I have this same problem! Something was nibbling on my elephant ear bulbs. They must not have tasted very good because one pot was untouched, the other just had a small bite out of it, they haven't been back since.
I've heard something about sprinkling cayenne pepper on top of the dirt, which I was planning on doing if they came back.

I have the same problem every year on my deck!
Cayenne pepper works (great for pouring between the planks of the deck too, to prevent Racoons from trolling underneath), but I use Chilli flakes in my potted plants, because they're more visible.

Blood meal works really well too...and it puts nitrogen (I think?) back into the soil. It's the only thing I've found to deter our squirrels from my tomatoes.

you know what i found in my just-potted flower pots last night? a buried whole peanut and a foil wrapped chocolate heart. the tell-tale mess of dirt, the freshly dug hole, and a glimpse of a bushy little tail told me a squirrel was hiding treats in my pots for safekeeping.

Wow, thanks! I put out some pepper flakes on top of the soil for now, so we'll see if that works some. Does anyone know if I can spray the tomatoes with some sort of pepper solution to keep the critters from eating them when they start to get ripe?

@designedtoteach: Red (capsicum) pepper will repel mammals but not birds. The reason behind it is pretty cool: the mammalian digestive system destroys pepper seeds but the bird digestive system doesn't. Plants with peppers mild enough to be eaten by a mammal didn't get re-seeded. If only birds can eat the peppers, the seeds get nicely dispersed with a little dollop of fertilizer.
My mother uses a home-made pepper/garlic spray to keep rats from eating her grapefruit to good effect.

I fill my pots with river rock. Keeps the squirrels from digging. This only works on established plants though. I have not found a good method for sprouting seeds, other than sprouting indoors

I once "painted" a wooden birdfeeder with hot sauce because the squirrels kept chewing on the wood to get at the seeds. It worked until the next rain. You can even buy capsicum treated birdseed, advertised as also giving the birds a few more vitamins.

I remember reading somewhere about making chicken wire cages around bulbs to keep the squirrels from eating them. The article (Diane Ackerman, maybe?) had this hilarious description of the squirrel, having dug down to the cage, running around and around trying to reach through the wire to the bulb from different angles. Maybe you could stretch chicken wire over the top of your pots until the plants get big enough for claussen's river rocks.

I find whole peanuts, walnuts, hazelnuts you name it. I thought I was going insane for years before I figured it out. My squirrel apparently buries way more than he needs too- because they are always sprouting come spring. I build little barricades with sticks which seem to at least slow him down.

Fence in your yard and let a dog loose...

For pots, my experiments have led me to the conclusion that the best deterant for squirrels is layering largish rocks on top of the soil. Pepper works for a day or two, but soon looses it's deterant capabilities. That could be because I'm in the fog belt and the moisture every evening kills off the smell? But rocks 1-3" in diameter keep the buggers out of the planters.

I've also had good luck bribing them. They stay out of my new, currently rock-free planters if I leave them raw peanuts every week or so. Ridiculous, yes. But we seem to have reached an agreement that works for both of us...and the dog loves watching them eat!

I've been planning on trying the chicken wire trick with my cat, who loves to dig in my potted plants. I have been using river rocks, but they tend to trap a lot of moisture and harbor fungus and gnats. A physical barrier like the chicken wire will probably be more effective than red pepper, but won't look as good.