No cause shall be heard earlier than thirty days after service upon the defendant or upon due publication as provided in section 38-1-103. Any number of separate parcels of property situate in the same county may be included in one petition, and the compensation for each shall be assessed separately by the same or different commissions or juries, as the court may direct. Amendment to the petition or to any paper or record in the cause may be permitted whenever necessary to a fair trial and final determination of the questions involved. Should it become necessary at any stage of the proceeding to bring a new party before the court, the court has the power to make such rule or order in relation thereto as may be deemed reasonable and proper, and also has the power to make all necessary rules and orders for notice to parties of the pendency of the proceeding and to issue all process necessary to the execution of orders and judgments as they may be entered.