Green Hawthorn Crataegus viridis
Green Hawthorn is a perennial tree native to the lower 48 states. It grows to 30 ft and blooms Mar in part shade – shade, with red fruit. A keystone plant for native insects and the food web.
More about this plant
Crataegus viridis, the green hawthorn or southern thorn, is a species of hawthorn that is native to the southeastern United States. The tree tends to grow to be 5–15 meters tall. Forms vary considerably, and many desirable ornamental forms could be selected from the wild. The cultivar 'Winter King' is a well-known selection. Wikipedia →
Growing & care
USDA PLANTS · TRY- Sun
- Part shade – shade
- Soil & moisture
- High moisture
- Soil pH
- 4.3–7.3
- Fertility need
- Medium
- Adapts to
- Medium (loam), Fine (clay)
- Hardiness
- USDA zone 5+
- Drought tolerance
- High
- Shade tolerance
- Low
- Wet-soil tolerance
- Low waterlogging
- Height
- 30 ft
- Mature width
- ~ 25 ft wide DERIVED derived estimate — open-grown crown allometry (height × growth-form ratio); not a measurement
- Spacing
- 8–12 ft apart from USDA planting density
- Spread
- None — clumping
- Growth rate
- Moderate
- Growth form
- Multiple stems
- Lifespan
- Perennial · long-lived
- Foliage
- Deciduous broadleaf · fine texture
- Active growth
- Spring & summer
- Fruit
- Red persists into winter
- Flower colour
- White AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
- Propagate by
- Seed, Bare root, Container
- Seed starting
- Needs cold stratification a cold-moist spell before it germinates
- Seeds ripen
- Spring – Autumn seed-collection / harvest window
- In the trade
- Routinely available
- Deer browsing
- High browsed readily
- Resprouts if cut
- Yes regrows after top-kill
Sow timing keys off your local last- and first-frost dates.
Wildlife & pollinators
How pollinator value is scored →❧ Caterpillar hosts ~168 caterpillar species
Crataegus supports ~168 caterpillar species.
Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is an exceptional genus.
Recorded feeding on Crataegus in North America, including:
+ 8 more species → ↑ show fewer
✦ Bees 1 bee visitor
1 native & managed bee species is documented visiting Green Hawthorn :
Wildlife & visitors 2 birds · 1 nectaring
Open records of who else uses Green Hawthorn — a generalist food-web signal, kept separate from the keystone Ecological Value.
Recorded eaten by 2 birds species (fruit, seed, browse):
1 adult butterfly & moth species is recorded nectaring at its flowers:
Across 42 U.S. vegetation-survey plots that recorded Green Hawthorn, these catalog species turned up most often in the same plot — a real field co-occurrence signal, not a planting prescription.
How we know this (4) Methods & honest limits
A recorded categorical fact: each species is tagged C3 (standard), C4 (heat/water-efficient) or CAM (succulent, night-time CO₂ uptake) — or a facultative combination. We only show a trait card for the noteworthy C4/CAM cases; C3 is the unremarkable majority, kept in the data but not surfaced as a card.
We take the plant’s U.S. county range and look up each county’s long-term climate, then summarise: native rainfall = the median annual rainfall across its counties; heat tolerance = the warm end (90th percentile) of average temperature across its range (mirroring how our cold-hardiness floor uses an extreme). Counties + medians blunt the roadside/observer bias that makes point-level climate unreliable. Needs at least five placeable counties.
Honest limits: A realized, sampling-biased niche (where it has been recorded, not its physiological optimum), and county climate is coarse — large Western counties span deserts and mountains. Derived guide, never a measured fact.
For woody plants that have a height but no measured crown, we estimate width = height × a crown-to-height ratio fit for that plant’s form (conifers narrower than broadleaf trees, shrubs widest), calibrated on our measured open-grown crowns and capped at the largest one ever measured. A measured crown always wins; herbaceous plants get nothing (no anchor).
Honest limits: A coarse class-median estimate for garden-scale spacing, not a measurement; woody single/multi-stem forms only.
McKenzie et al. assigned each species a flower colour with a GPT-4V vision model over iNaturalist photos. We use the confident tier plus a separately-labelled lower-confidence top-up (mostly inconspicuous green/brown flowers), and render it as a small tint — never as an asserted fact, and kept out of the written synopsis.
Honest limits: AI image inference (~87% expert agreement on the confident tier); a decorative, confidence-tiered indicator, not a measured trait.
Sources for this entry (37) Open & cited
Cite this page Open data, please attribute
PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).
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