Japanese Yellow Loosestrife

Lysimachia japonica

Native to:
Bangladesh, China, Hainan, India, Japan, Korea, Myanmar, Nansei-shoto, New Guinea, Ogasawara-shoto, Pakistan, Philippines, Sulawesi, Taiwan

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Primulaceae
Genus:
Lysimachia
Species:
Lysimachia japonica
USDA Symbol:
LYJA2

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
10 cm
Light Requirements:
Part Shade
Drought Tolerance:
Low
Bloom Months:
may,jun,jul
Bloom Colors:
yellow
Ground Cover:
Yes

Keystone Species Ranking

Pollen Specialist Bee Keystone:
★☆☆☆☆ Native pollen specialist bee species supported by this genus (NWF)

Soil Requirements

Soil Type:
rich, well-drained loamy soil
pH:
5.5 - 6.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
consistently moist
Notes:
Thrives in forest understories with ample organic matter.

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–30 days
Notes:
Seeds require light for germination. Surface sow and keep moist.

The above propagation data sourced from Claude AI

ORGHPS Germination Guide: Sow @ 20C. Germinates within 3 months.

Source: Ontario Rock Garden & Hardy Plant Society