Yucca filamentosa
Adam's Needle
About the plant
What it is and where it grows — not part of any germination protocol.
The plant
- Habit
- Broadleaf evergreenPlant Finder
- Habit
- Perennial, Forb/herb, Shrub, SubshrubPLANTS Database
- Height
- 4-8 ftPlant Finder
- Spread
- 2-3 ftPlant Finder
- Flower
- Showy; creamy whitePlant Finder
- Blooms
- June to JulyPlant Finder
- Native range
- Central and eastern United StatesPlant Finder
- Native range
- Native to the lower 48 statesPLANTS Database
- Hardiness zones
- 5-10Plant Finder
- Note
- Seed can be collected October to March: it sits in upright capsules over winter, and that is as good as dry storage.Seed Germination Theory and Practice, 2nd ed.
Growing conditions
- Sun
- Full sun
- Soil
- Light, dry to medium, well-drained; tolerates poor sandy soil
- Watering
- Dry to medium
Toxicity is noted only where a source states it. No note here is not a finding of safety.
Sources: Plant Finder — Missouri Botanical Garden; PLANTS Database — USDA NRCS; Seed Germination Theory and Practice, 2nd ed. — N. C. Deno.
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low
Start around June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 2026.
Dry storage
Duration: 180 daysTemperature: 70°F 21°C
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
11% came up here. Deno gives no length for this period; three months is his standard cycle.
Warm moist stratification
Temperature: 70°F 21°C
A further 85%.
about 9 months from start to sowing. Germination time not stated; 21 days assumed.
85% germination.
11% in the cold and 85% after the move: first up on the second day, then half of what is left every two days.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate
Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.
Dry storage
Duration: 180 daysTemperature: 70°F 21°C
Warm moist stratification
Temperature: 70°F 21°C
57%, first up on the second day, then half of what is left every twenty days.
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
Deno gives no length for this period; three months is his standard cycle.
Warm moist stratification
Temperature: 70°F 21°C
A further 43%, and this time half of what is left every day or two.
Steps after step 2 run on after germination.
about 6 months from start to sowing. Germination time not stated; 21 days assumed.
57% germination.
57% at 70, but half the packet only every twenty days. The 43% that follows a cold cycle arrives ten times faster -- which is Deno's point here.
This source doesn't state how long.