It's unfortunate but your foxglove might have reached the permanent wilting point and it won't comeback. No plant (well few) can stay alive for a week in a container especially if it's not getting water and foxgloves like water.
Container size and growing conditions are important too. Lots of plants are sold as decorative meaning it not expected to be long lived (see Poinsettias). It could be that might not be in an appropriate size pot (cheaper) and they could have been in controller conditions (cool with humidity) and continually dosed with high amounts fertilizer (attractive for sale) just prior to being sent to the store. Get it home and don't baby it and down it goes fast.
I've grown them once or twice (my climate is similar to yours) and find their water sensitive like tomatoes and sunflowers. Miss a day or so of water and they decline rapidly. Don't forget that humidity (and wind) can be almost as important as heat when it comes to plants. Plants dehydrate rapidly do to dry air and wind.
I'm familiar with your zone and it looks like it had been pretty warm in your area in addition to being dry over the weekend. I would suggest that a Foxglove never wants it's soil to get to the point where it is dry, always some moisture in the soil. Unfortunately (although not having seen it) I think it's just a matter low - no water and it wilted down.
Thank you for all your replies! A few of the leaves on the stems have perked up, and a couple of the stems themselves have gotten firm again… Is that a last gasp, or a good sign?
The only specific instructions I could find on any site about watering foxgloves was that in extreme heat or drought conditions, they should be watered once or twice a week; I naturally assumed that less would be fine when it's not getting above 80°F. I put a bunch of water on it the day I got it, and a little over a week later it was 95% dead. If it was supposed to be watered every day, this comes as no surprise… and that's beyond the amount of care that I can give it.
I have just received a fantastic Foxglove for Mother's day, with exactly the same results you had with yours. It was suggested to me (and makes sense) that they are "forced into prime" by some retailers to be sold for show, with no concern to what happens once bought . I was wondering,, do you still have the Foxglove you posted about in 2017?
