when to plant seeds for moss rose verbena
Moss rose can be started indoors or planted outside after the last frost. You can start it indoors in late February to mid March. Then transplant outside in early May. Start seeds outside in May. Follow the instructions on the seed packet.
Here is more about moss rose (Portulaca grandiflora):
https://www.gardeningknowhow.com/ornamental/flowers/portulaca/portulaca-plants.htm