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Planting agastache #925598
Asked March 07, 2026, 8:50 PM EST
Hennepin County Minnesota
Expert Response
Thank you for your question for Extension Master Gardeners. As you know, our climate can be so variable, but I would suggest you do the cold stratification now before you plant your seedlings outdoors. Here is how you'll need to do it for anise hyssop, one of my favorite native plants. It is too late to directly sow your seeds outdoors as that should be done in January.
Indoors: Cold, moist stratification. Start at least 5 weeks before outdoor night temperatures are reliably in the 10 C (50 F) range. Place seed on the surface of a slightly moistened, sterile, soil-less growing mix. Put this in a labelled, sealed plastic bag and store in a refrigerator for one day. The next day place this in the freezer for one day. Repeat this for one week, alternating between the fridge and the freezer. After stratifying, place mixture on the surface of pots filled with growing media. Seed needs light to germinate, do not cover after planting. Keep moist but not soggy and very warm (21 C - 70 F). When seedlings are 5 cm (2 inches) tall or more, transplant into the garden spaced 30 cm (1 foot) apart.
Good luck and happy gardening!