Pulmonarias are good front-of the-border plants as they only grow about 12" tall. Plant them 20-22" apart as they happily mound up with time. They are hardy little characters that thrive in Zones 3-7 and do just fine in normal or clay soil.
I grow three Pulmonaria varieties -- 'Raspberry Splash' (spotted foliage with magenta and purple flowers), 'Silver Streamers' (silver/white foliage with pink flowers that turn blue), and 'Cevennensis' (thinner foliage with blotched leaves and midnight blue flowers).