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swamp smartweed

Polygonum hydropiperoides ยท Polygonaceae

swamp smartweed (Polygonum hydropiperoides)
Photo: (c) James Hardee, some rights reserved (CC BY) ยท CC BY ยท via iNaturalist

swamp smartweed (Polygonum hydropiperoides) is a perennial herbaceous plant in the Polygonaceae family. It is native to North America. USDA records it as hardy in zone 10 and warmer, down to about 32ยฐF.

At a glance

Typeforb-herb USDA
Lifecycleperennial USDA
Native statusnative USDA
Lightfull-sun USDA
Water needmedium USDA
Growth rateslow USDA
Soil pH4.5โ€“8.8 USDA
Flower colorGreen USDA
Hardiness zones10 and warmer USDA
Guild layerunderstory Derived
Nursery availabilityRoutinely Available USDA

USDA quoted from the USDA PLANTS database ยท 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. It is recorded on soils from pH 4.5 to 8.8 โ€” a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 10; USDA publishes no warm-end limit, so gardeners in warmer zones should check local heat tolerance separately.

Size and growth

It grows slowly, which matters when you are timing a planting around the layers above it.

Role in a guild

Understory. In a layered planting this is the layer beneath the canopy, tall enough to hold structure but shaded from above. We derive the layer from the plant's growth habit and mature height using a fixed rule, so the same inputs always produce the same layer.

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Tags

deciduouswet-tolerantclay-tolerantdeer-resistantnativefull-sunslow-growing

Related plants

Others in Polygonum

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol POHY2, 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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