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Pure Air Natives
Silphium trifoliatum

Whorled Rosin Weed

Plants

50 Plug Tray Out of Stock

Description

Whorled Rosin Weed (Silphium trifoliatum) is a tall prairie native with bright yellow sunflower-like blooms that appear in mid to late summer. The flowers attract bees and butterflies. Plants grow upright with distinctive leaves arranged in whorls along the stem.

Whorled Rosin Weed grows best in full sun and prefers medium soils but tolerates a range of conditions. This species works well in prairie restorations, pollinator gardens, and large native plantings where tall flowering plants are needed.

Seed Details

Weight 15 lbs
Dimensions 22 × 12 × 11 in

Details

SociabilityClumps
Sun RequirementsFull Sun, Partial Sun
Soil MoistureDry-Mesic, Mesic
Height4-5'
USDA Zones5-8
Bloom ColorYellow
Bloom PeriodJuly, August, September
Plant Spacing2-3'

Seeds & Seed Mixes:

Seeds and seed mixes ship nationwide, year-round, typically within 3–5 business days. If you would like to postpone a seed mix shipment until fall, please note this at checkout.

Live Plants:

Live plants are available year-round while inventory lasts and ship to all states except California, Arizona, Oregon, Washington, Nevada, Alaska, and Hawaii. After your order is placed, we’ll contact you to coordinate a spring shipping window, as many plants are overwintered and ship once dormancy breaks.

Estimated shipping for 2026 plant orders begins in mid-April, weather permitting.

If you’re looking to secure plants in advance or need larger quantities for a project, we offer contract growing options. Contact us to discuss your needs and request a quote. Additional species not listed online may also be available through contract grow.

Live Stakes:

Live stakes are available by request only and must be ordered by submitting a contact form. Ordering is open seasonally from November 1 through February 28. A minimum of 100 stakes per order is required, with at least 25 stakes per species.

Live stakes ship only to the following states: Missouri, Minnesota, South Dakota, North Dakota, Nebraska, Kansas, Oklahoma, Arkansas, Tennessee, Kentucky, Illinois, Indiana, Ohio, Michigan, and Iowa.

PLS stands for Pure Live Seed, an industry-standard measure of seed quality. It reflects the portion of seed in a batch that is viable and capable of germinating.

What this means for you: when you purchase 1 lb. of PLS seed, the physical weight of the seed you receive will be slightly more than 1 lb. That’s because we account for non-viable seed and natural inert material upfront, so you receive a full pound of live, plantable seed.

Many companies sell bulk seed by total weight, which can include filler and non-viable seed. By pricing based on PLS, we make sure you’re getting exactly what you paid for—high-quality native seed with more predictable, successful germination.

Want to dive deeper? Check out our in-depth article on what PLS is and why it matters.