You can store the dahlias in. You can store the dahlias in the pots. Just make sure that the garage doesn't get too cold in the winter. You can cover the pots with a blanket or tarp to give the bulbs a bit more protection. Also make sure that the soil is not too wet.
An unsigned copy of a document may be used for reference only or it may be a file copy (when it is not necessary to have a signed copy of the document). /s/ on a signature line means that the signature is on the original document, not on the copy that you're holding. It is a representation that the original document is properly signed, but for some reason you only have an unsigned copy of the document.
the sign (,), a mark of punctuation used for indicating a division in a sentence, as in setting off a word, phrase, or clause, especially when such a division is accompanied by a slight pause or is to be noted in order to give order to the sequential elements of the sentence.