harvest as in to store for winter or harvest as in you want to eat it?

Both. I want to try to eat a couple and would also like to keep a pup or two for next year.

Good questions. Mine might be the same as yours but it's too early for me to tell. The leaves on mine are thicker than a Colocasia esculenta. In this pic it is 34 days old and it's from a grocery store produce section: https://st.hzcdn.com/simgs/f3f25c3509b40752_8-0583/home-design.jpg (pic is here on gardenweb)

For my decorative-only Taros, I wait for a few frosts before digging them out. That's also when I separate the small pups from the parent and pot them. Then for the parent I'll decide whether to pot it or cure the corm. Thus far I've only potted these for the winter and all survived. Last year I may have waited 4-5 frosts because that's when the last flowers (inflorescences) stopped developing and died.

I've read that waiting until after frosts forces dormancy which is better for potting or curing. I've also noticed that it's better to wait until then because the pups have more roots at that time. I've separated smaller pups with little or no roots in early and mid summer and most either died or took over a month to grow again.

Next year I plan to harvest some of mine. I'll eat the ones with corms the size of the one I got in the store (pups?). The rest I'll either pot or cure (parent?). So I won't know which to harvest until I dig them out and see the corms.

Jay, thanks for the comments. I'll probably do the same and wait until after the first frost to harvest. Can you explain your 'cure' process?

It may just mean 'drying'. I'm going by an aggregation of what I've read. Over-drying & fungus are said to be the main concerns. Search some Aroid forums on here to see what others do too. I haven't cured a Tarot yet. I've only cured 1 Caladium corm and I'm curing a second after they went dormant this month. Potted Caladium with 3 bulbs: After the last leaf died I removed the root cluster from the pot, let it dry for 4-5 days, then trimmed the longer roots & leaf stems from the bulbs and brushed off the dirt, then let them dry for 3-4 more days. Then I put them in a paper sandwich bag with peat moss and put it in my basement. I'll check on them monthly & mist a little. I haven't done that before and hope it grows again in the Spring. Caladium in-ground with 1 bulb: After the last leaf died I dug it up, then trimmed the longer roots & leaf stems from the bulbs and brushed off the dirt, now I'm letting it dry for 1 week, maybe more. Then I'll pot it again...yes, after just 1 week. This one I want as an indoor plant this winter.