Anise Hyssop (Agastache foeniculum)

Difficulty: ⭐☆☆☆☆
(Very easy — produces abundant seed that germinates readily with minimal treatment.)

Seed Collection Time:

Late summer to early fall — typically August through October.

Signs Seeds are Ready:

• Flower spikes fade from purple to brown as blooming finishes.

• The seed heads become dry and brittle.

• Tiny dark brown to black seeds develop inside the persistent calyces.

• When rubbed between your fingers, mature seeds fall out easily.

Seed Collection Steps:

• Wait until most of the flower spikes have turned brown and dried.

• Cut the entire seed heads on a dry day.

• Place them upside down in a paper bag or on a drying tray for several days.

• Rub or shake the dried seed heads to release the seeds.

• Separate seeds from the chaff using a fine sieve or by gently winnowing.

• Store in a cool, dry place until sowing.

Germination Tips:

Cold stratification is optional but often improves germination speed and uniformity.

C(30): Refrigerate in a moist medium for about 30 days, or sow outdoors in late fall for natural stratification.

Seeds require light for best germination—surface sow or cover only very lightly with fine soil or vermiculite. Keep the growing medium consistently moist until seedlings emerge, which typically occurs within 1–3 weeks under warm conditions.