No, Ipomoea seeds last quite a long time. They do however have a tough outer shell so it is often recommend to EITHER soak them in warm water for 24 hours OR nick or lightly sandpaper the seeds before planting. Without doing that, they may take some time to germinate. So you may eventually see plants pop up in the vicinity that you planted them. I prefer to start in pots and transplant while still small.
Remy