Answer: There's a reason agastache is often called giant hyssop! Your plant will bloom by mid-July so don't prune it back until after the flowers are spent. Agastache actually prefer to grow in lean soils so don't fertilize. If you do, you may get only lush, green growth at the expense of flowers. Just enjoy your plant and encourage its growth with a deep soaking once each week during the growing season.
Best wishes with your garden!
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