Tub of sunflowers, I might just have to do this. If I put my bird feeder in the middle of the tub, I wouldn't even have to plant the seeds myself. (I only put sunflower seeds in my feeder to cut down on weeds waste. The grackles usually don't eat them leave the other birds alone most of the time too.)
The newspaper will prevent any grass and weed seeds from germinating, but unlike fabric, it will decompose after about 18 months. By that time, any grass and weed seeds that were present in the soil on planting will be dead. It’s green, it’s cheaper than fabric, and when you decide to remove or redesign the bed later on, you will not have the headache you would with fabric.