flat pea
Lathyrus sylvestris · Fabaceae
flat pea (Lathyrus sylvestris) is a perennial vine in the Fabaceae family. It is introduced to North America rather than native. USDA records it as hardy in zone 3 and warmer, down to about -38°F.
At a glance
| Type | vine Derived |
|---|---|
| Lifecycle | perennial USDA |
| Native status | introduced USDA |
| Mature height | 2.2 ft USDA |
| Light | shade USDA |
| Water need | low USDA |
| Growth rate | moderate USDA |
| Soil pH | 5–7.8 USDA |
| Bloom | June USDA |
| Flower color | Purple USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | climber Derived |
| Nursery availability | Routinely Available USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It tolerates full shade. USDA rates it as having low water needs once established. Its drought tolerance is rated high. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 5 to 7.8 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 2.2 ft, making it about knee height. It grows at a moderate rate.
Bloom period
USDA records a bloom period of June. Flowers are purple.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, medium in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as long.
What the site needs to provide
USDA records it across sites receiving 30 to 55 inches of annual precipitation. It needs at least 140 frost-free days to finish its season. It roots to at least 12 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
Propagating it
Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It spreads vegetatively at a moderate rate.
Resilience and wildlife
Browsing animals find it highly palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated high. Its growth form is recorded as rhizomatous.
Role in a guild
Climber. In a layered planting this is it uses other plants or structures for vertical support rather than standing on its own. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Lathyrus
- Caley pea Lathyrus hirsutus
- beach pea Lathyrus japonicus
- perennial pea Lathyrus latifolius
- silky beach pea Lathyrus littoralis
Similar role and hardiness
- Oriental bittersweet Celastrus orbiculatus
- American bittersweet Celastrus scandens
- western white clematis Clematis ligusticifolia
- climbing hempvine Mikania scandens
- crownvetch Securigera varia
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol LASY, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, lifespan, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer, Type.
Read our full data sources and methodology.
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