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About the plant What it is and where it grows — not part of any germination protocol.
The plant
Habit Herbaceous Perennial Extension Gardener Plant Toolbox
Habit perennial Plants of the World Online
Height 2-7 ft 0.6-2.1 m Extension Gardener Plant Toolbox
Spread 0.8-2 ft 25-60 cm Extension Gardener Plant Toolbox
Flower Green, Purple/Lavender, White Extension Gardener Plant Toolbox
Blooms Summer Extension Gardener Plant Toolbox
Hardiness zones 3-7 Extension Gardener Plant Toolbox Growing conditions
Sun Dappled Sunlight; Full sun; Partial Shade Extension Gardener Plant Toolbox
Soil High Organic Matter Extension Gardener Plant Toolbox
Soil pH Acid (<6.0), Neutral (6.0-8.0) Extension Gardener Plant Toolbox
Moisture Good Drainage, Moist Extension Gardener Plant Toolbox Toxicity is noted only where a source states it. No note here is not a finding of safety.
Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew.
Worth knowing Poke milkweed resembles common milkweed and can hybridize with it where the two grow close together. Its leaves can grow quite large in moist shade. Wikipedia: Asclepias exaltata This source reports 6 treatments. All are shown.
Protocol 1 N. C. Deno, 1993 Difficulty Moderate Rated by us, not by the source.
Start around January 3, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 2, 2026.
1 Dry storage
Duration: 360 days · Temperature: 70°F 21°C
2 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: light
about 15 months from start to step 3. Germination happens during step 3, in 8 days.
100% germination in 4–8 days.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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 N. C. Deno, 1993 Difficulty Low Rated by us, not by the source.
Start around March 24, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 23, 2026.
1 Dry storage
Duration: 360 days · Temperature: 70°F 21°C
2 Sow and cover
Temperature: 70°F 21°C · Light: light
about 12 months from start to sowing. Then 18 days to germinate.
99% germination in 8–18 days.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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 N. C. Deno, 1993 Difficulty High Rated by us, not by the source.
Start around December 15, 2026 for a May 3 last frost.
1 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 3 months from start to step 2. Germination happens during step 2; time not stated, 21 days assumed.
21% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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 N. C. Deno, 1993 Difficulty Very high Rated by us, not by the source.
Start around December 21, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on December 20, 2025.
1 Dry storage
Duration: 360 days · Temperature: 70°F 21°C
2 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
about 15 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.
7% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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 N. C. Deno, 1993 Difficulty Very high Rated by us, not by the source.
Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.
1 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
2 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 6 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.
6% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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 6 N. C. Deno, 1993 1 Dry storage
Duration: 360 days · Temperature: 70°F 21°C
2 Sow and cover
Temperature: 70°F 21°C · Light: dark
about 12 months from start to sowing.
0% germination.
Nothing germinated at 70.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Asclepias p. 103Public domain Show the original text Asclepias (Asclepiadaceae). The four species studied have wind born seed indicating that DS is tolerated. This was generally true; but some deterioration on DS was noted in A. phytolaccoides germination is strongly augmented by light as shown by 70L(99% in 8-18 d), 40-70L(100% in 4-8 d), none in 70D, and 40-70D(7%) This was for seed collected in February which had already undergone considerable DS in the seed capsule. Fresher seed collected in November gave a little more germination in the dark as shown by 70-40-70(6%) and 40-70(21%).. Seed DS 12 m at 70 showed the same photorequirements as fresh seed, but the percent germination was reduced to 25% showing that there had been some death of the seed Over this extended DS. Treatment with GA-3 in 70D gave about the same percentage and rate of germination as in 70L. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Asclepias p. 103. 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
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