Quickened Summoning (3.5e Feat)
From D&D Wiki
 Quickened Summoning [General]
You are able to summon monsters quicker than normal.
Any spells whose name begin with Summon that normally have a 1 round casting time instead have a casting time of 1 full-round action when you cast them.
Summon spells such as, summon nature’s ally, summon monster, and summon swarm have a casting time of one round and do not take effect until the following combat round.