cup plant
Silphium perfoliatum · Asteraceae
cup plant (Silphium perfoliatum) is a perennial herbaceous plant in the Asteraceae family. It is native to North America. USDA records it as hardy in zone 2 and warmer, down to about -49°F.
⚠ Invasive or noxious status. USDA lists this plant with an invasive or noxious weed status somewhere in its range. Check your state's noxious weed list before planting it — in some states it is illegal to sell or plant.
Both flags are quoted from USDA PLANTS, not inferred.
At a glance
| Type | forb-herb USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 6 ft USDA |
| Light | part-shade USDA |
| Growth rate | rapid USDA |
| Soil pH | 4.5–7.5 USDA |
| Bloom | August–September USDA |
| Flower color | Yellow USDA |
| Hardiness zones | 2 and warmer USDA |
| Guild layer | herb-layer Derived |
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 grows in partial shade. Its drought tolerance is rated low. It is recorded on soils from pH 4.5 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 2.
Size and growth
At maturity it reaches about 6 ft, making it a plant that will finish above head height. It grows quickly.
Bloom period
USDA records a bloom period of August through September. Flowers are yellow.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, coarse in texture. Its flowers are conspicuous. Its active growth period is summer.
What the site needs to provide
USDA records it across sites receiving 16 to 51 inches of annual precipitation. It needs at least 128 frost-free days to finish its season.
Propagating it
Propagate it from seed and container stock. Seed needs cold stratification — a period of moist chilling — before it will germinate, so sow in autumn or chill it artificially before a spring sowing.
Role in a guild
Herb layer. In a layered planting this is the herbaceous middle — perennials and grasses that fill the space between ground cover and shrubs. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol SIPE2, 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, cold stratification, Drought tolerance, fall conspicuous, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, Growth rate, Hardiness zones, Invasive status, Lifecycle, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, precipitation max in, precipitation min in, propagation, resprout ability, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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