Alexandria laurel (Calophyllum inophyllum), photographi

Can I Grow Alexandria Laurel in Delaware?

USDA Zones 7a-8a · Plant zone range 11-12

Unlikely — Zone Mismatch

Alexandria laurel (zones 11-12) does not overlap with Delaware's zone range (7a-8a). Growing outdoors is unlikely without significant protection.

2 zones short — what would close it

Alexandria Laurel is hardy to zone 11, and the warmest ground in Delaware is zone 8 — 2 zones short. Planted in open ground it will not survive a Delaware winter. To grow it here, grow alexandria laurel in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 11-12 (plant) against 7-8 (Delaware). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

Alexandria Laurel in Delaware — the short answer

Alexandria Laurel in Delaware: hardy in zones 11–12, full sun.

Plant zones
11-12
Hardy to zone 10b: Tropical Plants Database (Useful Tropical Plants) lists -1 °C, converted to zone 10b, checked Oct 2026. The source rates it slightly hardier than our range. Ceiling: our plant database.
Delaware zones
7a-8a
USDA PHZM 2023
Frost window
Mar 23 - Mar 23 – Nov 17 - Nov 19
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
238 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free to start

Your yard isn't the whole zone.

Delaware spans zones 7a-8a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score alexandria laurel against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your parcel report in seconds — read in full free for your first 14 days

Where Alexandria Laurel Stands in Delaware

Alexandria Laurel is rated for zones 11–12 — a cold floor USDA puts at 40 to 50°F. No Delaware county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Delaware winters, not about alexandria laurel.

Below the zone 11 floor

3 counties

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Zone Comparison

Alexandria Laurel Needs

  • USDA Zones: 11-12
  • Sun: Full Sun
  • Mature size: 40 ft tall
  • Drought tolerance: High

Delaware Has

  • USDA Zones: 7a-8a
  • Last Hard Freeze (28°F): Mar 23 - Mar 23
  • First Hard Freeze (28°F): Nov 17 - Nov 19
  • Annual Rainfall: 42-48 inches
  • Common Soils: Sandy loam, Silt loam, Tidal marsh

Plant Zone Range (zones 11-12)

11a
12b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.0 – 8.0

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Alexandria Laurel in Delaware

The frost window

Across Delaware, the last spring hard freeze (28°F) clears between Mar 23 and Mar 23, and the first fall hard freeze lands between Nov 17 and Nov 19 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 239-day window you can count on — up to 241 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

Winter standing

Delaware runs as cold as USDA zone 7, and no sourced winter-hardiness floor is on record for alexandria laurel, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether alexandria laurel is a permanent planting or a replant-every-spring crop for you turns on your own zone within Delaware; check its hardiness range against that before treating it as long-lived ground.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Soil + Drainage Fit

Alexandria Laurel tolerates a wide pH range (pH 5-8) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Delaware. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 7 — worth knowing before you decide whether a Delaware soil test result is a problem or just a number. Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.

Your land, not the state average

Delaware's soils run mostly sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Alexandria Laurel needs about 7 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how alexandria laurel performs.

Check your parcel → Source: USDA NRCS SSURGO.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Delaware soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant alexandria laurel for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before alexandria laurel goes in. What follows is Delaware’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Delaware — and how to grow with it.

Federal record: High

We checked the federal record across Delaware — 3,371 documented sites across 7 of the 8 source types we track.

The most significant on record: 64 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Delaware carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds of imported, lab-tested soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across Delaware

Severity Distribution

across Delaware

High49Moderate686Low2,636

Highest-Severity Sites

Superfund · Superfund NPL
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected

Know Before You Grow

  • •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
  • •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
  • •Near a brownfield, a raised bed of imported, lab-tested soil lowers contact with the ground; it does not remove it.

Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.

What Else to Consider for Alexandria Laurel in Delaware

Zone compatibility tells you about winter cold survival — but Delaware growers also need to think about:

Sandy soils in southern DE drain too quickly

Salt spray damage near the coast

Rising water tables in low-lying areas

Growing alexandria laurel here specifically

Delaware's soils run mostly sandy loam (Ultisols), and whether that suits alexandria laurel's pH 5.0–8.0 preference comes down to your exact parcel, not the statewide picture.

Pull your parcel's SSURGO map unit, test pH, and amend toward alexandria laurel's 5.0–8.0 target before planting. How to handle it →

What to actually do about these — and the constraints that apply to every Delaware grower, not just alexandria laurel — is covered on the Delaware growing guide.

Where in Delaware Alexandria Laurel Is Zone-Hardy

Alexandria Laurel is rated for USDA zones 11–12. No Delaware county reaches it. Even Sussex County, the state’s mildest winter at zone 7b, sits below the plant’s zone 11 floor — so in open ground this one needs winter protection here, or a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Alexandria Laurel’s zone 11–12 band: Hardy to zone 10b: Tropical Plants Database (Useful Tropical Plants) lists -1 °C, converted to zone 10b, checked Oct 2026. The source rates it slightly hardier than our range. Ceiling: our plant database.. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

Pollinator + Wildlife Value

Alexandria Laurel draws honeybees and native bees (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, alexandria laurel can only work that bloom inside Delaware's frost window — roughly 241 days, opening after the last 28°F freeze (Mar 23 - Mar 23) and closing at the first (Nov 17 - Nov 19), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.

Good to Know Before You Plant Alexandria Laurel

Alexandria Laurel is listed as toxic to dogs, cats (seeds) at a moderate level. (Source: Cornell Poisonous Plants Database.) Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Parts of alexandria laurel carry slight for people, so know which parts are edible before harvest.

Delaware Cooperative Extension

For Delaware-specific cultivar recommendations, planting calendars, and pest pressure for alexandria laurel, the canonical source is University of Delaware Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Alexandria Laurel native to Delaware?

No — the USDA PLANTS Database lists Alexandria Laurel as introduced rather than native in the Lower 48, so it is not part of Delaware's native flora. It grows here as a garden plant; pairing it with a few Delaware natives keeps local pollinators fed too.

Looking for plants that belong here? The Delaware growing guide lists plants that USDA PLANTS records growing in Delaware and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.

State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.

Common Questions About Growing Alexandria Laurel in Delaware

When can I plant Alexandria Laurel in Delaware?

Delaware's last spring hard freeze (28°F) clears between Mar 23 and Mar 23, and the first fall hard freeze lands between Nov 17 and Nov 19 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Alexandria Laurel, so this page does not state whether it overwinters in Delaware and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Alexandria Laurel grown in across Delaware?

Delaware spans USDA hardiness zones 7a-8a (USDA ARS PHZM 2023). Alexandria Laurel is listed for zones 11-12, which do not overlap them, so there is no zone in Delaware where this page can call outdoor growing reliable. A parcel report resolves your own address's zone.

How many frost-free days does a typical Delaware site have?

A typical Delaware site sees ~241 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Alexandria Laurel needs 365+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Alexandria Laurel native to Delaware?

No — the USDA PLANTS Database lists Alexandria Laurel as introduced rather than native in the Lower 48, so it is not part of Delaware's native flora. It grows here as a garden plant; pairing it with a few Delaware natives keeps local pollinators fed too.

How should I amend the soil for Alexandria Laurel in Delaware?

Alexandria Laurel tolerates pH 5-8 and poorly (saturated >50% of year) drainage (FAO ECOCROP). That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Delaware site — amend for drainage and organic matter first.

Will Alexandria Laurel actually grow on my specific land in Delaware?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores alexandria laurel against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free to start

Check your specific parcel in Delaware

State-level data is a sketch. Your Growable Ground report scores alexandria laurel against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.

Three things about your lot that Delaware alexandria laurel averages can't show:

Your soil pHYour frost-free days — Delaware averages 241Your sun & shade

We read public map data around Delaware — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Delaware alexandria laurel average

Explore More

Explore Delaware county by county

Delaware carries 3 counties with their own USDA zone — a sample of the growing pages for alexandria laurel there:

Where else alexandria laurel grows

Alexandria Laurel's zone band crosses state lines — these are the states closest to Delaware in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.

More to grow in Delaware

Delaware has a growing page for 1,005 plants — a rotating sample of the rest of the shelf.

Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →

Cite this dataset

Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643

Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643

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