Sweet William Catchfly 
Silene armeria
This happy late-summer pest-free flower is native to Southern Europe and became a garden flower fashion favorite during the 1600s.  Also called London Pride, the plant is perennial in Zone 6 and warmer, otherwise treat as an annual.   Depending on soil, plants can reach the height of 12 to 18 inches and will reseed freely.  Sweet William Catchfly is easy to naturalize but the best news is that pollinators love it, especially rare butterflies.  
50 seeds