Viris Illustribus: What is Hannibal saying?

I am reading the Viris Illustribus
(available online here: http://www.slu.edu/colleges/AS/languages/classical/latin/tchmat/readers/lhomond/lho3a.htm#marc)

In the Secon Punic War part, under the subsection ‘MARCUS CLAUDIUS MARCELLUS’, Hannibal is besieging a city called Casilinum and trying to starve it out, the residents of Casilinum are holding out by eating mice and roots. At this point hannibal says something that I do not understand at all:

Miratus
Annibal exclamavit:
Eone usque
dum ea nascantur,
ad Casilinum
sessurus sum?

I cannot work this out, is he saying something like:

“When will I be sitting in Casilinum, not while these people still live!” (are being born? nascantur??)

“Amazed, Hannibal exclaimed: ‘I am therefore still going to be encamped at Casilinum even to that time when those [radishes] are born/sprouted?’”

“eo usque” means “so long, even to that time.”
“ea” refers to the radishes, “rapum,” referred to in the previous paragraph. “nascor” can mean both “be born,” and to be produced/generated/grown more generally.

“Is that how it is to be [/the way of it], that I am going to be encamped at Casilinum until they are grown [/as long as they are growing]”, i.e., ea = rapa = the turnips

Didn’t see your post, thesaurus
Epistulam tuam, thesaure, non vidi