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Flower Pictured: Iris bulleyana , a relative Morten Ross CC BY 4.0 Illustration W. R. Dykes, The Genus Iris (1913), plate III Public domain About the plant What it is and where it grows — not part of any germination protocol.
Habit rhizomatous geophyte Plants of the World Online
Flower Yellow Flora of China
Native range China South-Central, Myanmar, Tibet GBIF Backbone Taxonomy 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; Flora of China — Wu Zhengyi, Peter H. Raven and Hong Deyuan (eds.); GBIF Backbone Taxonomy — Global Biodiversity Information Facility.
Worth knowing Named for the plant collector and explorer George Forrest, and sometimes called Yunnan iris. It is known as easy to grow, and its yellow flowers are fragrant. Wikipedia: Iris forrestii For a May 3 last frost, start this around December 8, 2026 — about 5 months ahead.
This one takes two seasons. Start in December 2026 to plant out in May 2027.
Using a national average last frost of May 3, which is wrong for most places. Put in your zip code for your own dates. Plant words explained .
Protocol N. C. Deno, 1993 Difficulty High Rated by us, not by the source.
1 Clean the flesh off the seed
2 Leach in running water
Duration: 7 days
Washed and cleaned daily for 7 days.
3 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
4 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
5 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
6 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
Steps after step 4 run on after germination.
about 3 months from start to step 4. Germination happens during step 4; time not stated, 21 days assumed.
50% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Iris p. 156Public domain Show the original text Iris (Iridaceae). This genus gave -not only great diversity in germination behavior but also some of the most extended multicycle germination observed. Germination is always hypogeal, and true leaves develop in 'a week or two once the radicle emerges even when germination was delayed for years. Empty seed coats and deformed seeds are relatively easy to recognize so that seed counts and percent germination are accurate. A major problem is how to stimulate the germination of Oncocyclus and Regelia Iris since they have such extended natural germinations. Panayoti Kelaidis of the Denver Botanical Garden has iritorrmed me that Fritz Kummert In Austria, Frank Norris in Tennessee (USA), and David Shahak in Israel are growing Oncocyclus Iris from seed in large numbers. Panayoti said that there are reports that germination was much improved by rinsing the seed in dilute Chlorox (aqueous NaOCI) and rubbing off the seed coats after which the seeds germ. readily at 40. There are also reports that gibberelic acid and other chemicals stimulate germination. Data is needed using scientific procedures. A recent book, "The Iris" by B. Mathew, is devoted to this genus. Mathew divides the genus into six subgenera with further division into sections and series. His arrangement is used only in part. The species are arranged in alphabetical order for convenience with subgenus or section indicated in parentheses using the abbreviations B (bearded), Bx (beardless), E (Evansia), 'N (Nepalensis), .0 (Oncocyclus), P (Pardanthopsis), A (Regelia), At (Aeticulata), and X (Xiphium). I. forrestli (Bx) germ. best (100% in March and April) if the DS seed was WC 7d or 4 w and sown outdoors in November. Other treatments germ. less or in a more extended manner as shown by 40-70(2/4)-40-70(214) and none when sown at 70. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Iris p. 156. 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. How each step is done , in Deno’s words, and what Verified and Derived mean.
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