Deno’s GardenMy Garden

Scirpoides holoschoenus

Round-headed Clubrush · Roundhead Bulrush

Family CyperaceaeGenus Scirpoides

Also published as Scirpus holoschoenus. You are in the right place.

Round shaggy cream flower heads clustered along a smooth green rush-like stem, among dry grass.
FlowerIsidre blancCC BY-SA 4.0

About the plant

What it is and where it grows — not part of any germination protocol.

Habit
perennialPlants of the World Online
Flower
CreamRead from the photograph on this page

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Plants of the World Online — Royal Botanic Gardens, Kew; Read from the photograph on this page — Deno's Garden.

Two sources report 5 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Low Rated by us, not by the source.

Start around March 16, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 15, 2025.

  1. Dry storage

    Duration: 730 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 2 years from start to sowing. Then 21 days to germinate.

85% germination in 7–21 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Scirpus p. 61Public domain
Show the original text
Scirpus (Cyperaceae). S. holoschoenus DS 2 y germ. 70L(85% in 1-3 w) and 70D(none). The conclusion given in the 1 st Suppl. is revised. It is now concluded that there has been no significant dying or disappearance of the light requirement in seeds DS of up to 2 y. Seeds DS 3 y germ. 70L(70% in 2nd w) and 70D(none).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Scirpus p. 61. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 2

DerivedN. C. Deno, 1998

Difficulty Low Rated by us, not by the source.

Start around March 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 22, 2024.

  1. Dry storage

    Duration: 1095 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 3 years from start to sowing. Then 14 days to germinate.

70% germination in 14 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Scirpus p. 61Public domain
Show the original text
Scirpus (Cyperaceae). S. holoschoenus DS 2 y germ. 70L(85% in 1-3 w) and 70D(none). The conclusion given in the 1 st Suppl. is revised. It is now concluded that there has been no significant dying or disappearance of the light requirement in seeds DS of up to 2 y. Seeds DS 3 y germ. 70L(70% in 2nd w) and 70D(none).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Scirpus p. 61. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 3

DerivedN. C. Deno, 1996

Difficulty Low Rated by us, not by the source.

Start around July 31, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 30, 2026.

  1. Dry storage

    Duration: 240 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 8 months from start to sowing. Then 9 days to germinate.

100% germination in 7–9 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Scirpus p. 76Public domain
Show the original text
Scirpus (Cyperaceae). S. holoschoenus DS 8 m germ. 70L(100% in 7-9 d) and none in 70D, 70 GA-3, or 40. A prior 3 m at 40 had no effect. Seeds DS 2 y germ. 70L(86% in 2nd w) indicating some dying and a slowing of rate of germination. The seeds still failed to germinate in 70D.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Scirpus p. 76. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 4

DerivedN. C. Deno, 1996

Difficulty Low Rated by us, not by the source.

Start around March 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 22, 2025.

  1. Dry storage

    Duration: 730 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 2 years from start to sowing. Then 14 days to germinate.

86% germination in 14 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Scirpus p. 76Public domain
Show the original text
Scirpus (Cyperaceae). S. holoschoenus DS 8 m germ. 70L(100% in 7-9 d) and none in 70D, 70 GA-3, or 40. A prior 3 m at 40 had no effect. Seeds DS 2 y germ. 70L(86% in 2nd w) indicating some dying and a slowing of rate of germination. The seeds still failed to germinate in 70D.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Scirpus p. 76. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 5

DerivedN. C. Deno, 1996

  1. Dry storage

    Duration: 240 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

about 8 months from start to sowing.

0% germination.

Nothing germinated at 70.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Scirpus p. 76Public domain
Show the original text
Scirpus (Cyperaceae). S. holoschoenus DS 8 m germ. 70L(100% in 7-9 d) and none in 70D, 70 GA-3, or 40. A prior 3 m at 40 had no effect. Seeds DS 2 y germ. 70L(86% in 2nd w) indicating some dying and a slowing of rate of germination. The seeds still failed to germinate in 70D.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Scirpus p. 76. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

Add to My Garden

View species page