Beach Pea
Lathyrus japonicus
- Native to:
- Aleutian Is., Baltic States, Belgium, Canada, China, Denmark, Finland, Føroyar, France, Germany, Greenland, Iceland, Ireland, Japan, Korea, Kuril Is., Labrador, Nansei-shoto, Norway, Poland, Prince Edward I., Russia, Sweden, United States
Krzysztof Ziarnek, Kenraiz
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Fabaceae
- Genus:
- Lathyrus
- Species:
- Lathyrus japonicus
- USDA Symbol:
- LAJA
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb , Vine
- Height:
- 90 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- jun,jul,aug
- Bloom Colors:
- purple, pink, violet
- Ground Cover:
- Yes
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★★☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Host Plant for Caterpillars
Ancylis maritima, Ancylis metamelana, Ancylis sp., pea moth (Cydia nigricana), Pima boisduvaliella, white-edged pima moth (Pima albiplagiatella), zebra caterpillar moth (Melanchra picta), Silvery Blue (Glaucopsyche lygdamus)
Reported Fauna Sightings
Bees: Yellow head bumble bee (Bombus flavifrons)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies
- Salt Tolerant:
- Yes
Soil Requirements
- Soil Type:
- sandy, nutrient-poor, well-drained soil
- pH:
- 5.5 - 7.5 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- Commonly found in coastal areas with sandy soils.
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Scarification:
- Seed coat scarification required before sowing
- Germination Time:
- 14–42 days
- Notes:
- Scarification of the hard seed coat is required; soaking in warm water or mechanical nicking improves germination rates.
The above propagation data sourced from Claude AI
Pre-treatment: Mechanical scarification with sandpaper. Cold-moist stratification is optional as it doesn't significantly affect the germination rate.
Establishment: Seeds that are not scarified have a very low germination rate (2-12%). Seeds are collected in July and August. The plant is found in temperate coastal areas of North and South America, Europe, and Asia.
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 20C. Germinates within 3 months. Resents transplanting. | Requires scarification. | Requires soaking 24-48 hrs; discard floaters.