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St. Johnswort

Hypericum calycinum · Hypericaceae · all Hypericum records

Your local evidence lens

Separate evidence questions, never one approval badge

Set a ZIP to compare this record with state distribution, native range, USDA hardiness, and invasive records.

A genus split is not a placement verdict. Set a ZIP to read the local documented split.

1. Fire evidence and conditions

Fire evidence
Fire-resistant — location does not change the cited classification.
Fire-performance conditions
1 condition stated in cited fire-evidence rows.
Fire ecology context
No section-reviewed fire-ecology context is normalized.
Placement evidence
3 source placement records; source schemes remain separate.
Evidence regions
California; Maryland, New Jersey, and West Virginia; New Zealand; Ohio / Midwest; Southern California; Tennessee; Virginia / Mid-Atlantic
Maintenance
No sourced horticultural maintenance assertion is normalized; fire-test conditions do not supply maintenance advice.
Typed publication scope: 7 scopes across 5 cited fire sources
  • Defensible Space Landscaping in the Urban/Wildland Interface: A Compilation of Fire Performance Ratings of Residential Landscape Plants · Official scoped edition
    • CA; partial normalized coverage · 1997-07-01

      The UC Forest Products Laboratory says the guide covers properties of common California landscaping plants and was prepared for California fire agencies. FireApproved publishes 130 exact owners at historical California publication scope. The report is a 1997 compilation, not a current endorsement, site rating, or independent test of every row.

  • Firewise Landscaping Plants (Maryland, New Jersey, and West Virginia editions) · Official scoped edition
    • MD; partial normalized coverage · 2015-01-08

      Maryland Forest Service says the list contains plants that can be grown in Maryland and identifies Maryland natives. FireApproved publishes 169 exact source owners from the 180 printed rows; an unrepresentable form and duplicate-owner rows are not broadened. The list calls itself non-comprehensive and does not establish suitability for every Maryland site.

    • NJ; partial normalized coverage

      New Jersey DEP publishes a state edition saying the listed plants can be grown in New Jersey and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and does not establish suitability for every New Jersey site or override the Pinelands Commission's separate placement and fuel-break rules.

    • WV; partial normalized coverage · 2026-08-26

      West Virginia Division of Forestry publishes a state edition saying the listed plants can be grown in West Virginia and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and provides no comparative or site-specific rating.

  • Firewise Landscaping (OSU Extension Bulletin 921) · Official scoped edition
    • OH; partial normalized coverage · 2006-03-01

      Ohio State University Extension Bulletin 921 is an Ohio publication that describes Ohio fire seasons and landscape conditions and labels nativity to Ohio. FireApproved publishes 352 exact source-owning plant records from its eight rated tables. This historical publication scope does not assert current extension endorsement or that a listed plant suits every Ohio site.

  • Landscaping Guidelines to Protect Your Home from Wildfire (SP685) · Official scoped edition
    • TN; partial normalized coverage · 2006-10-24

      University of Tennessee Extension SP685 is Tennessee landscape guidance and publishes 78 represented plant owners. Most table rows are a carrier of Virginia Firescapes rather than an independent rating; Tennessee source scope does not change that lineage or establish site suitability.

  • Virginia Firescapes — Firewise Landscaping for Woodland Homes (430-300) · Official scoped edition
    • VA; partial normalized coverage · 2009-04-15

      Virginia Cooperative Extension's publication opens with Virginia wildfire conditions, identifies its Virginia Firewise Landscaping Task Force, and labels plants native to Virginia. FireApproved publishes 306 exact source owners. Publication scope does not establish parcel suitability or current endorsement of this archived 2009 list.

2. Why this plant is relevant here

State distribution
Documented in CA, OH, OR, TN, WA.
Native range
No current cited or legacy state native range is normalized.
Introduced / established
1 sourced range or established record; set a location to match them. This is not an invasive warning.
USDA hardiness
Documented minimum 2b; no upper limit is documented.

3. Legal, ecological, and broader status

Legal-list status
Set a location for an exact legal-list result; source silence is not clearance.
Seed-list status
Set a location to compare the separate state noxious-weed seed layer.
Reported invasive here
No ecological invasive report is normalized; that does not prove noninvasiveness.
Broader regional context
Aggregate AK, HI, and L48 evidence is shown only as regional context, never as an exact-state finding.
Federal context
Federal designations remain separate from state legal-list results.
How to read this page

The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.

St. Johnswort (Hypericum calycinum)
Photo: (c) zebedeugalinha, some rights reserved (CC BY) (CC BY), via iNaturalist. Species-typical, not necessarily this cultivar.
Form
groundcover
USDA hardiness
Minimum 2b; upper limit not documented
Mature height
~0.8 ft
Water need
moderate
Grows in
CA, OH, OR, TN, WA
Rated in
California; Maryland, New Jersey, and West Virginia; New Zealand; Ohio / Midwest +3
Uses
ground-cover
Family
Hypericaceae
Evidence
8 cited sources

Plant hardiness evidence

These values describe the plant source. Your ZIP zone comes from the separate 2023 USDA Plant Hardiness Zone Map. Whole-zone values stay whole-zone, and a single unresolved value is not treated as a tolerance range. Different source boundaries stay separate: overlapping statements are compared independently, while only ranges with no shared zone are called a conflict.

Conditions in the fire evidence

These describe tested or rated plant material. They are not horticultural maintenance instructions.

Where its sources say to plant it

Placement rules below use each source's own distances or named zones, tied to its rating. They are not interchangeable with the directory's current Zone 0 guidance.

The evidence

Grouped by what each source concluded. Primary evidence rated the plant itself (a lab, field program, or original curation); corroboration compiled or republished another source's rating and resolves to its root lineage.

Recommends (6)

Mid-scale / conditional (2)

Same genus in the directory · the Hypericum group page

Last verified 2026-08-23. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata · ITIS

Hypericum calycinum (St. Johnswort). FireApproved. https://fireapproved.com/plants/hypericum-calycinum/. Last verified 2026-08-23.