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western waterleaf

Hydrophyllum occidentale · Hydrophyllaceae

western waterleaf (Hydrophyllum occidentale)
Photo: Wikimedia Commons · Public domain · via Wikimedia Commons

western waterleaf (Hydrophyllum occidentale) is a perennial herbaceous plant in the Hydrophyllaceae family. It is native to North America. USDA records it as hardy in zone 5 and warmer, down to about -18°F.

At a glance

Typeforb-herb USDA
Lifecycleperennial USDA
Native statusnative USDA
Mature height1.5 ft USDA
Lightshade USDA
Water needmedium USDA
Growth ratemoderate USDA
Soil pH6.2–7.5 USDA
BloomMay–June USDA
Flower colorWhite USDA
Hardiness zones5 and warmer USDA
Guild layerground-cover 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 tolerates full shade. 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 6.2 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 5.

Size and growth

At maturity it reaches about 1.5 ft, making it about knee height. It grows at a moderate rate.

Bloom period

USDA records a bloom period of May through June. Flowers are white.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is dark green, coarse in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as short, so plan on replacing or resowing it rather than treating it as permanent structure.

What the site needs to provide

USDA records it across sites receiving 10 to 24 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 120 frost-free days to finish its season. It roots to at least 14 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

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. Its seed spreads at a slow rate. It does not spread vegetatively, so it will stay where you put it.

Resilience and wildlife

Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated low. Its growth form is recorded as single crown.

Role in a guild

Ground cover. In a layered planting this is the lowest layer — it shades soil, holds moisture, and suppresses weeds. The layer is derived by a fixed rule from growth habit and mature height.

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Tags

deciduousdrought-tolerantwet-tolerantdeer-resistantnativeshade-tolerantground-cover

Related plants

Others in Hydrophyllum

Similar role and hardiness

Where this data comes from

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