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Yucca glauca

Beargrass · Great Plains Yucca · Spanish Bayonet · Soapweed Yucca

Family AsparagaceaeGenus Yucca

A rosette of stiff blue-gray leaves radiating from the center
The whole plantNickCC BY-SA 4.0

About the plant

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

Safety

Toxicity
Low severity. Roots. Saponins.Extension Gardener Plant Toolbox

The plant

Habit
Herbaceous Perennial, Perennial, Shrub, SucculentExtension Gardener Plant Toolbox
Habit
subshrub or shrubPlants of the World Online
Height
1 ft30 cmPLANTS Database
Flower
Green, WhiteExtension Gardener Plant Toolbox
Blooms
SummerExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sunExtension Gardener Plant Toolbox
Soil
Loam (Silt), Shallow RockyExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), Alkaline (>8.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Occasionally Dry, Very DryExtension Gardener Plant Toolbox
Watering
Drought tolerance: HighPLANTS Database

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; PLANTS Database — USDA NRCS.

Worth knowing

  • Like all yuccas, it depends on yucca moths to pollinate it, and the moths' larvae depend on its seeds for food. It is also called soapweed. Wikipedia: Yucca glauca

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around March 27, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 9 days to germinate.

90% germination in 5–9 days.

90% sown warm, most of it inside nine days. Fresh seed or six months' dry storage at 70 or 40 -- Deno got the same either way.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, YuccaPublic domain
Show the original text
Yucca (Liliaceae). V. glauca germ. 70(90% largely in 5-9 d) and 40-70(80-90% in 2-4 d) with either fresh seed or seed DS 6 m at 70 or 40..
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Yucca. 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, 1993

Difficulty Low Rated by us, not by the source.

Start around January 1, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    Deno gives no length for this period; three months is his standard cycle.

  2. Warm moist stratification

    Temperature: 70°F 21°C

about 3 months from start to step 2. Germination happens during step 2, in 4 days.

80% germination in 2–4 days.

80-90% and quicker off the mark after a cold period. Fresh seed or six months' dry storage at 70 or 40 -- Deno got the same either way.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, YuccaPublic domain
Show the original text
Yucca (Liliaceae). V. glauca germ. 70(90% largely in 5-9 d) and 40-70(80-90% in 2-4 d) with either fresh seed or seed DS 6 m at 70 or 40..
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Yucca. 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.

Germination trials

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

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