How did people preserve plants over long journeys?

Question

As in, sailors who have brought exotic plants across seas. Without storage room for freshwater for the plants, how do they water them?

Answer 1

And of course you needn't water seed until you plant it.

Answer 2

Probably with the same fresh water the sailors drank.  I know the invention of little glass houses made transporting plans much easier and created a more dynamic exchange of plant materials