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Betulaceae family

American Hornbeam Carpinus caroliniana

Native
Deer-resistant — Low palatability to browsing deer. Usually passed over, but no plant is truly deer-proof when food is scarce.
Also known as: Blue beech · Hornbeam · Musclewood

American Hornbeam is a perennial tree native to Canada and the lower 48 states. It grows to 30 ft and blooms Apr in full sun, with brown fruit.

More about this plant

Carpinus caroliniana, the American hornbeam, is a small hardwood understory tree in the genus Carpinus. American hornbeam is also known as blue-beech, ironwood, musclewood and muscle beech for the distinctive sinewy, muscle-like appearance of its trunk. It is native to eastern North America, from Minnesota to southern Quebec, east to Maine, and south to eastern Texas and northern Florida. It occurs in shaded areas with moist soil, particularly near the banks of streams or rivers, and is often a natural understory species of the riverine and maritime forests of eastern temperate North America. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
USDA PLANTS — Sun · Soil & moisture
USDA — SoilPH — Soil pH
USDA PLANTS (DwCA, Zenodo 17903503) — Fertility Requirement / Soil Adaptation — Fertility need · Adapts to
USDA — Temp-Min °F — Hardiness
Niinemets & Valladares 2006 (CC0) — Drought tolerance · Shade tolerance · Wet-soil tolerance
Sun
Full sun
Soil & moisture
Medium moisture
Soil pH
4–7.4
Fertility need
Medium
Adapts to
Coarse (sandy), Medium (loam)
Hardiness
USDA zone 4+
Drought tolerance
Low
Shade tolerance
High
Wet-soil tolerance
Low waterlogging
Size & form
Sources · Size & form
USDA PLANTS (DwCA, Zenodo 17903503) — Height, Mature — Height
Tallo — Jucker et al. 2025 (CC BY 4.0) — wild crown width — Mature width
USDA PLANTS (DwCA, Zenodo 17903503) — Planting Density (per acre) — Spacing
USDA PLANTS (DwCA, Zenodo 17903503) — Growth Rate / Spread / Growth Form / Lifespan / Active Growth Period / Seed Period — Spread · Growth rate · Growth form · Active growth
USDA PLANTS — Lifespan
TRY Plant Trait Database (CC BY 4.0) · USDA PLANTS — Foliage
USDA PLANTS (DwCA, Zenodo 17903503) — Fruit/Seed Color / Fruit Persistence — Fruit
Lifespan: USDA’s lifespan scale for trees: short = under ~100 years · moderate = 100–250 · long = over 250. Balsam fir and other short-lived conifers are genuinely short for a tree, not short like an annual.
Height
30 ft
Mature width
≈ 35 ft wide wild/forest-grown — open-grown specimens spread wider
Spacing
6–8 ft apart from USDA planting density
Spread
None — clumping
Growth rate
Slow
Growth form
Multiple stems
Lifespan
Perennial · short-lived
Foliage
Deciduous broadleaf · medium texture
Active growth
Spring & summer
Fruit
Brown
In the garden
Sources · In the garden
USDA PLANTS (DwCA, Zenodo 17903503) — Propagation Method / Commercial Availability — Propagate by · In the trade
USDA PLANTS (DwCA, Zenodo 17903503) — Germination (cold stratification) — Seed starting
USDA PLANTS — Seed Period — Seeds ripen
USDA PLANTS (DwCA, Zenodo 17903503) — Foliage Texture / Browse Palatability / Resprout — Deer browsing · Resprouts if cut
Propagate by
Seed, Bare root, Container
Seed starting
Needs cold stratification a cold-moist spell before it germinates
Seeds ripen
Summer – Autumn seed-collection / harvest window
In the trade
Routinely available
Deer browsing
Low often deer-resistant
Resprouts if cut
Yes regrows after top-kill
Sub-canopy / understory layer — Sits in the understory of a layered food forest or polyculture.Open guide →
derived roles
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Fall colour
Bloom (the flower's colour) Fall colour
Bloom · Apr — USDA PLANTS (DwCA, Zenodo 17903503) — BloomPeriod
Fall colour · 8,175 obs · USA-NPN observed “coloured leaves” — timing varies by site & year
When to sow · for your area

Sow timing keys off your local last- and first-frost dates.

Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~68 caterpillar species

Carpinus supports ~68 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 a strong genus.

Recorded feeding on Carpinus in North America, including:

Acrobasis carpinivorella · snout moth ✦ Acronicta americana · American Dagger Moth ✦ Acronicta grisea · Gray Dagger ✦ Anisota virginiensis · Pink-Striped Oakworm ✦ Antheraea polyphemus · Polyphemus Moth ✦ Apatelodes torrefacta · Spotted Apatelodes ✦
+ 8 more species →
Apoda y-inversum · Inverted Y Slug Moth ✦ Automeris io · giant silk moth ✦ Baileya dormitans · Sleeping Baileya ✦ Baileya ophthalmica · Eyed Baileya ✦ Basilarchia arthemis · brush-footed butterfly ✦ Besma endropiaria · Straw Besma ✦ Cameraria corylisella · leaf-blotch miner moth ✦ Cameraria ostryarella · leaf-blotch miner moth ✦
Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0). ✦ = recorded on this exact species.
Wildlife & visitors 1 bird · 2 nectaring

Open records of who else uses American Hornbeam — a generalist food-web signal, kept separate from the keystone Ecological Value.

Recorded eaten by 1 bird species (fruit, seed, browse):

Bonasa umbellus · Ruffed Grouse

2 adult butterfly & moth species are recorded nectaring at its flowers:

Halysidota tessellaris · Banded Tussock Moth Elaphria versicolor · Variegated Midget
Interaction records (observations, not exhaustive) from GloBI → (CC0). Counts are distinct species; names are the most-recorded. Common names from Wikidata (CC0).
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
Frequently grows with

Across 468 U.S. vegetation-survey plots that recorded American Hornbeam, these catalog species turned up most often in the same plot — a real field co-occurrence signal, not a planting prescription.

Sweetgum · 86% Eastern Poison Ivy · 86% Red Maple · 80% Muscadine · 78% Virginia Creeper · 77% Roundleaf Greenbrier · 64% Crossvine · 62% American Holly · 62%
By region — what it grows with near you
"%" = share of this plant's plots that also held the species. From sPlotOpen → (Sabatini et al. 2021, CC BY 4.0) — open vegetation plots: wild community composition, not garden design.
How we know this (3) Methods & honest limits
Leaf build Direct fact

We read each species’ measured specific leaf area (leaf area per unit dry weight) from the Global Spectrum dataset and band it: thin & fast (high SLA), medium, or thick & tough (low SLA). The global median is about 10 mm²/mg.

Honest limits: A species-mean from pooled measurements — individual plants vary with light and site. A broad strategy signal, not a precise per-plant figure.

Díaz, S. et al. (2022) The global spectrum of plant form and function: enhanced species-level trait dataset. Scientific Data 9:755.
Photosynthesis Direct fact

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.

Kattge, J. et al. TRY plant trait database — Categorical Traits Dataset (2012).
Climate niche (heat tolerance & native rainfall) Derived

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.

Realized-niche / climate-envelope approach (Pearson & Dawson 2003; Soberón 2007). Climate: NOAA NCEI nClimDiv county normals (1991–2020).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (37) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[18] Invasive / introduced status — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[19] Wetland indicator — USACE National Wetland Plant List (2022)
[21] Description — Wikipedia (CC BY-SA)
[22] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[24] Conservation rank — NatureServe Explorer (CC BY)
[26] Functional traits — TRY Plant Trait Database (CC BY 4.0)
[27] Photosynthetic pathway — TRY Plant Trait Database (CC BY 4.0)
[28] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[29] Wildlife & visitors — GloBI — Global Biotic Interactions (CC0)
[32] Other common names — Wikidata (CC0)
[33] Stress tolerance — Niinemets & Valladares 2006 (CC0)
[34] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[35] Caterpillar species — NHM HOSTS (CC0)
[36] County range — GBIF Open Data — open-licensed occurrences (CC0/CC-BY) → county
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
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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