Deno’s GardenMy Garden

Forsythia suspensa

Golden-bell · Weeping Forsythia · Forsythia · Golden Bell Tree

Family OleaceaeGenus Forsythia

Long green shoots set with pointed toothed leaves
LeafKENPEICC BY-SA 3.0

About the plant

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

The plant

Habit
Deciduous shrubPlant Finder
Habit
shrubPlants of the World Online
Height
6-10 ft1.8-3 mPlant Finder
Spread
6-10 ft1.8-3 mPlant Finder
Flower
Showy; yellowPlant Finder
Blooms
March to AprilPlant Finder
Native range
ChinaPlant Finder
Hardiness zones
5-8Plant Finder

Growing conditions

Sun
Full sun to part shadePlant Finder
Soil
Clay, High Organic Matter, Loam (Silt)Extension Gardener Plant Toolbox
Soil pH
5.0-7.5PLANTS Database
Moisture
Good Drainage, Moist, Occasionally DryExtension Gardener Plant Toolbox
Watering
MediumPlant Finder

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 of the World Online — Royal Botanic Gardens, Kew; Extension Gardener Plant Toolbox — NC State Extension; PLANTS Database — USDA NRCS.

Worth knowing

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. Warm moist stratification

    Temperature: 70°F 21°C

    10% germinated at 70 before the cold period.

  2. Cold moist stratification

    Temperature: 40°F 4°C

  3. Warm moist stratification

    Temperature: 70°F 21°C

    A further 20% after the cold period.

Germination happens during step 3; time not stated, 21 days assumed.

10% germination.

A tenth comes up before the cold period and a fifth more after it.

This source doesn't state how long steps 1 and 2 last.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, ForsythiaPublic domain
Show the original text
Forsythia (Oleaceae). F. suspensa germ. 70(10%)-40-70(20%) and 40-70(10%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Forsythia. 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 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

  2. Warm moist stratification

    Temperature: 70°F 21°C

Germination happens during step 2; time not stated, 21 days assumed.

10% germination.

This source doesn't state how long step 1 lasts.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, ForsythiaPublic domain
Show the original text
Forsythia (Oleaceae). F. suspensa germ. 70(10%)-40-70(20%) and 40-70(10%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Forsythia. 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