Pasture Thistle (Cirsium discolor)

Difficulty: ⭐⭐☆☆☆
(Moderate — seed heads are easy to collect but must be timed carefully to avoid loss to fluff dispersal or goldfinches)

Seed Collection Time:

Late summer to early fall — typically August through September

Signs Seeds are Ready:

• Flower heads fade and dry into silvery, fluffy seed heads

• Seeds (achenes) are attached to long, silky pappus hairs (parachutes)

• When mature, fluff pulls out easily and seeds separate from the base

• Goldfinches may begin foraging — a sign seeds are viable and dispersing

Tip: Check daily once fluff appears — wind and birds can clear a plant fast.

Seed Collection Steps:

1. Monitor drying flower heads and clip when fluff just begins to emerge

2. Collect heads into paper bags or cloth sacks to prevent wind dispersal

3. Air-dry for 3–5 days until heads are crisp

4. Gently pull or shake fluff to release seeds

5. Separate seeds from fluff by hand or using fine mesh screens

Note: Seeds are heavier than fluff — winnowing works well for final cleaning.

Germination Tips:

• Seeds are non-dormant but benefit from cold moist stratification for 30–60 days for improved germination

• Sow in fall for natural stratification or cold-treat in refrigerator

• Germinate in 1–3 weeks under moist, warm conditions

Note: Plants often flower in their second year and reseed readily.