Species
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Pelargonium zonale (L.) L'Hér.

Horse-shoe Pelargonium, Horseshoe Geranium, Horseshoe Geranium (EN); Zonierte Pelargonie (DE); Geranio rosado (ES), Horseshoe Pelargonium

Climate known 24 photographs
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Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

Summary

Pelargonium zonale is a species of Pelargonium native to southern Africa in the western regions of the Cape Provinces, in the geranium family. It is one of the parents of the widely cultivated plant Pelargonium × hortorum, often called "geranium", "horseshoe geranium", "zonal geranium" or "zonal pelargonium".

Text from Wikipedia, “Pelargonium zonale”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Pelargonium

Pelargonium is a genus of flowering plants commonly called geraniums, pelargoniums, or storksbills. It includes about 280 species of perennials, succulents, and shrubs. Taxonomist Carl Linnaeus originally included all the species of Pelargonium and Geranium under the latter name. More on Wikipedia ›

The opening of Wikipedia, “Pelargonium”, CC BY-SA 4.0, quoted as written.

Family
Geraniaceae
Described by
(L.) L'Hér.
Native to
Cape Provinces, KwaZulu-Natal
Wild records
601 in range· 181 open

At a glance

Warmest month
26°C
Feb, mean day; nights 16 °C (CHELSA)
Rain
574mm/yr
12 wet months · peak Oct 63 mm (CHELSA)
Light
17–48DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Rain rule: no season, 70% of the rain takes 8 months (February and April to October in the northern hemisphere). Habitat rain 574 mm a year, wettest October at 63 mm, driest June at 31 mm (habitat calendar, southern hemisphere). Open sky over the habitat: 17 to 48 mol/m²/day. Cold floor 0.9 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Campylia variegata (L.fil.) Sweet; Ciconium clarum Hoffmanns.; Ciconium cocciniflorum Hoffmanns.; Ciconium crenatum (Link) Hoffmanns.; Ciconium densiflorum Eckl. & Zeyh. and 45 more.

Cultivation

Its year Rain rule: no season, 70% of the rain takes 8 months (February and April to October in the northern hemisphere).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads no season: 70% of the year's rain (438 mm of 574 mm) takes 8 months, October to April and August. Mean temperature moves 9.5 °C between the warmest and coldest month. Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: February and April to October.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 574 mm a year, wettest October at 63 mm, driest June at 31 mm (habitat calendar, southern hemisphere).

This species’ habitat figures, with their source.

574 mm a year at the habitat, 438 mm of it October to April and August. Wettest month October at 63 mm, driest June at 31 mm. Across the envelope cells the year's total runs 378 mm to 932 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, southern hemisphere).

CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light Open sky over the habitat: 17 to 48 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 17 to 48 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 16, the highest 90th-percentile month 51).

CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Warmth and air Cold floor 0.9 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is 0.9 °C, the absolute minimum -1.9 °C, about 1 frost night a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.3 °C. Monthly means: coldest night 5.5 °C in July (across the envelope cells 2.5 °C to 11.5 °C), warmest day 25.9 °C in February (median year across the envelope cells, CHELSA). Cold floor: 0.9 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 53 to 61% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

Habitat climate through the yearMean day from 17 °C in Jun to 26 °C in Feb; mean night from 6 °C in Jul to 16 °C in Feb. The cold quarter, Jun to Aug, is the three months around the coldest night. 574 mm of rain a year, most in Oct. The bands show the 10th to 90th percentile across 260 habitat cells. Over 44 years at the typical cell the absolute minimum was -1.9 °C and the 99th-percentile day 37.3 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-10°10°20°30°40°frost37.3° 99th-percentile day (undated)-1.9° lowest night in 44 yrs (undated)°C · day and nightcold quarter0255075100mm rainDLI 17–48RH 53–61 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 260 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C26 / 23–2926 / 23–2924 / 22–2722 / 20–2420 / 18–2217 / 14–1917 / 14–1918 / 16–2019 / 18–2221 / 19–2323 / 20–2524 / 22–27
Night °C15 / 12–1816 / 13–1814 / 12–1712 / 9–169 / 6–146 / 3–126 / 3–127 / 4–128 / 5–1310 / 7–1412 / 9–1514 / 11–17
Rain mm51 / 27–8647 / 24–8061 / 37–9053 / 39–8036 / 23–6831 / 20–6232 / 19–6145 / 26–8637 / 21–6563 / 36–9763 / 34–9755 / 32–89
DLI47 / 41–5142 / 37–4534 / 32–3726 / 25–2820 / 19–2317 / 16–2019 / 17–2124 / 22–2631 / 30–3338 / 35–4045 / 40–4748 / 42–50
RH %60 / 55–6461 / 56–6460 / 56–6458 / 55–6355 / 52–5854 / 51–5653 / 50–5655 / 52–5957 / 53–6159 / 56–6260 / 55–6360 / 55–63

Each figure is the median across the 260 grid cells holding the 591 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 2453:4141 (-32.675, 27.075). Over 44 years there: absolute minimum -1.9 °C, 1st-percentile night 0.9 °C, 99th-percentile day 37.3 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 260 distinct grid cells holding the 591 in-range records; extremes and elevation at the typical cell 2453:4141 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell -32.50_26.875, lapse-corrected -199 m at 6.5 °C/km. Elevation: ETOPO 2022, 849 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeCape Provinces, KwaZulu-Natal· introduced: Spain, Morocco, Canary Is., Cape Verde, Madeira, Uzbekistan, Korea, East Himalaya, Myanmar, Vietnam, California, Mexico Southwest, Cuba, Dominican Republic, Haiti, Puerto Rico, Trinidad-Tobago, Amsterdam-St.Paul Is.
Kew's description“subshrub or shrub” · “subtropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker-33.633, 22.598 · in the densest population, 394 records (66% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 601 georeferenced records inside the native range; the map shows only the 181 openly licensed ones, which alone would put the marker 5 km away. 248 records outside the range (gardens, roadsides, misidentifications) ignored. 10 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 601 in-range records; it decides nothing.

Photographs

Pelargonium zonalePelargonium zonalePelargonium zonalePelargonium zonalePelargonium zonalePelargonium zonalePelargonium zonalePelargonium zonale

Photographs: Peter Warren, CC0, iNaturalist via GBIF (6); Shaun Swanepoel, CC BY, iNaturalist via GBIF (2).

Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Pelargonium zonale, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Optical Properties and Nondestructive Estimation of Anthocyanin Content in Plant Leaves¶
Anatoly A. Gitelson, Mark N. Merzlyak, О. Б. Чивкунова (2001) · Photochemistry and Photobiology
Bacterial wilt disease and the Ralstonia solanacearum species complex
Caitilyn Allen, Philippe Prior, Alice Hayward (2005) · HAL (Le Centre pour la Communication Scientifique Directe)
INTRODUCTION TO EUROPE OF RALSTONIA SOLANACEARUM BIOVAR 2, RACE 3 IN PELARGONIUM ZONALE CUTTINGS
J. Janse, H. E. van den Beld, J. G. Elphinstone, S. A. Simpkins (2004) · Journal of Plant Pathology
Biosynthesis, characterization and antimicrobial activities assessment of fabricated selenium nanoparticles using Pelargonium zonale leaf extract
Borna Fardsadegh, Hamideh Vaghari, Roya Mohammad-Jafari, Yahya Najian (2018) · Green Processing and Synthesis
In Situ Molecular Analysis of Plant Tissues by Live Single-Cell Mass Spectrometry
Mónica Lorenzo Tejedor, Hajime Mizuno, Naohiro Tsuyama, Takanori Harada (2011) · Analytical Chemistry
Influence of biochar, mycorrhizal inoculation, and fertilizer rate on growth and flowering of Pelargonium (Pelargonium zonale L.) plants
Giulia Conversa, Anna Bonasia, Corrado Lazzizera, A. Elia (2015) · Frontiers in Plant Science
EDTA-assisted phytoextraction of lead and cadmium by Pelargonium cultivars grown on spiked soil
Iram Gul, Maria Manzoor, Jérôme Silvestre, Muhammad Rizwan (2019) · International Journal of Phytoremediation

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

Other Pelargonium 5 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild not askedcarried from build of 2026-09-19 (rederive); that build: not asked: 16 wild photographs already from the GBIF download
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: filled 2026-09-20
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 75 datasets via GBIF.org; each carries its own licence.