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valley redstem

Ammannia coccinea · Lythraceae

valley redstem (Ammannia coccinea)
Photo: (c) Duarte Frade, some rights reserved (CC BY) · CC BY · via iNaturalist

valley redstem (Ammannia coccinea) is a annual herbaceous plant in the Lythraceae family. It is native to North America. USDA records it as hardy in zone 3 and warmer, down to about -38°F.

At a glance

Typeforb-herb Derived
Lifecycleannual USDA
Native statusnative USDA
Mature height1.6 ft USDA
Lightfull-sun USDA
Water needmedium USDA
Growth ratemoderate USDA
Soil pH4–5.9 USDA
Flower colorPurple USDA
Hardiness zones3 and warmer USDA
Guild layerherb-layer Derived
Nursery availabilityNo Known Source 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 needs full sun. USDA rates it as having moderate water needs. Its drought tolerance is rated medium. It handles periodically wet ground (USDA rates its anaerobic tolerance medium). It is recorded on soils from pH 4 to 5.9 — acidic ground. Its cold limit is zone 3.

Size and growth

At maturity it reaches about 1.6 ft, making it about knee height. It grows at a moderate rate.

Foliage, flower and season

Summer foliage is green, medium in texture. Its flowers are conspicuous. Its active growth period is spring.

What the site needs to provide

USDA records it across sites receiving 16 to 60 inches of annual precipitation. It needs at least 120 frost-free days to finish its season. It roots to at least 12 inches. Fertility requirement: medium.

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 does not spread vegetatively, so it will stay where you put it.

Resilience and wildlife

Its fire tolerance is rated low. Its growth form is recorded as single crown.

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.

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Tags

deciduousdrought-tolerantwet-tolerantclay-tolerantacidic-soilnativefull-sun

Related plants

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol AMCO, 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.

Read our full data sources and methodology.

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