If, at the time of the service of the attachment, the claim upon which suit is brought is not due, the defendant need not appear in the action until the maturity of the demand, unless the defendant elects to plead, in which event the cause shall stand for trial when it is reached in its regular order, and no final judgment shall be rendered therein before the maturity of the debt unless such election is made, but if perishable property is levied upon, it may be sold as in other attachment cases.
Iowa Code § 639.10