Deno’s GardenMy Garden

Rhododendron groenlandicum

Bog Labrador Tea · Greenland Labrador Tea · Labrador Tea

Family EricaceaeGenus Rhododendron

A domed head of small white flowers with protruding stamens, at the tip of a stem clothed in narrow dark leaves.
FlowerRobert Flogaus-FaustCC BY 4.0

About the plant

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

Habit
subshrubPlants of the World Online
Flower
White, creamFlora of North America
Native range
Alaska, Alberta, British Columbia, Connecticut, Greenland, Idaho and elsewhereGBIF 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; Flora of North America — Flora of North America Editorial Committee; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • Long known as Ledum groenlandicum. Its common names include Labrador tea and Hudson's Bay tea, but it contains toxic alkaloids that poison livestock. Wikipedia: Rhododendron groenlandicum

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. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

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

63% germination in 14–28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Ledum p. 165Public domain
Show the original text
Ledum (Ericaceae). L. groenlandicum germ. 70D GA-3(63% in 2-4 w), 700- 40-70D(23% in 4th w), and 40-70-40(none). Light had no effect.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ledum p. 165. 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 December 8, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C Light: either

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

about 3 months from start to step 2. Germination happens during step 2, in 28 days.

23% germination in 28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Ledum p. 165Public domain
Show the original text
Ledum (Ericaceae). L. groenlandicum germ. 70D GA-3(63% in 2-4 w), 700- 40-70D(23% in 4th w), and 40-70-40(none). Light had no effect.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ledum p. 165. 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

Add to My Garden

View species page