Mendel’s Gardens

Hesperoyucca whipplei

Chaparral Yucca

Family AsparagaceaeGenus Hesperoyucca

Also published as Yucca whipplei. You are in the right place.

About the plant

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

The plant

Habit
Perennial, Forb/herb, Shrub, Subshrub
Height
4 ft
Flower
White
Blooms
Late Spring
Native range
Native to the lower 48 states

Growing conditions

Sun
Shade tolerance: High
Moisture
Moisture use: Low

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

Source: PLANTS Database — USDA NRCS.

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around March 8, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 28 days to germinate.

40% germination in 14–28 days.

40-50%, fresh or after six months dry at 70.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, YuccaPublic domain
Show the original text
Yucca (Liliaceae). V. whipplel germ. 70(40-50% in 2-4 w) with either fresh seed or seed DS 6 m at 70. Germination dropped to 3% when sown at 40 even after four cycles.
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 Very high Rated by us, not by the source.

Start around March 15, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

    3%, even after four cycles.

No stated waiting before sowing. Germination time not stated; 21 days assumed.

3% germination.

3%, and four cycles did not improve it. Do not sow this one cold.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, YuccaPublic domain
Show the original text
Yucca (Liliaceae). V. whipplel germ. 70(40-50% in 2-4 w) with either fresh seed or seed DS 6 m at 70. Germination dropped to 3% when sown at 40 even after four cycles.
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.