@kelbell76
Welcome!
Your Agastache might have gotten too much water.
Agastache are drought tolerant (after the plants get established) and don't like to be watered a lot. They like a gravel mulch. They don't like to over fertilized. They like a lean and well draining soil. They like to be in full sun or full sun and partial shade. Plant the crown of the plant high and mulch with gravel to keep the water draining from the plant. Don't cut the stems in the fall to help with winter hardiness. Cut the old stems in spring after the threat of frost/freeze. Sometimes I wait till late spring to cut the old stems in case there's a late frost/freeze.
What variety do you have? Where in the US (or elsewhere) are you located?
