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Tropaeolum azureum

Blue Nasturtium

Family TropaeolaceaeGenus Tropaeolum

Violet-blue flowers with white and yellow throats, held on thin stalks above a bare woody stem with curling tendrils.
FlowerDick Culbert from Gibsons, B.C., CanadaCC BY 2.0

About the plant

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

Habit
climbing tuberous geophytePlants of the World Online
Flower
VioletRead from the photograph on this page
Native range
Chile CentralGBIF 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; Read from the photograph on this page — Deno's Garden; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

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 15, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

Germination happens during step 1; time not stated, 21 days assumed.

30% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Tropaeolum p. 225Public domain
Show the original text
Tropaeolum (Tropaeolaceae). Although they have not been exhaustively studied, the best germinations were obtained by giving the seeds -4w at 70 and shifting to 40. Germination at 40 occurs in the 3rd w, but the seedlings must be kept at 40 until the stem begins to emerge (hypogeal). Several of these species are hardy in England if the tuber is below frost line. Young plants need to be grown under milder conditions until is tuber is large enough to place below frost line. It remains to be seen if deep planting of the tuber can effect hardiness in Eastern U.S. T. azureum germ. best if given 4 w at 70 and then shifted to 40. These germ. 62% in 3rd wafter the shift to 40. Seeds also germ. 70D(1/10) and 40(3/10).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Tropaeolum p. 225. 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 High Rated by us, not by the source.

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

  1. Sow and cover

    Temperature: 70°F 21°C Light: dark

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

10% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Tropaeolum p. 225Public domain
Show the original text
Tropaeolum (Tropaeolaceae). Although they have not been exhaustively studied, the best germinations were obtained by giving the seeds -4w at 70 and shifting to 40. Germination at 40 occurs in the 3rd w, but the seedlings must be kept at 40 until the stem begins to emerge (hypogeal). Several of these species are hardy in England if the tuber is below frost line. Young plants need to be grown under milder conditions until is tuber is large enough to place below frost line. It remains to be seen if deep planting of the tuber can effect hardiness in Eastern U.S. T. azureum germ. best if given 4 w at 70 and then shifted to 40. These germ. 62% in 3rd wafter the shift to 40. Seeds also germ. 70D(1/10) and 40(3/10).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Tropaeolum p. 225. 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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