Maltese cross (Jerusalem cross) Silene chalcedonica
Maltese cross (Jerusalem cross) (Silene chalcedonica) is a deciduous perennial flowering plant in the Caryophyllaceae family, native to European Russia, Central Asia and Mongolia. It grows 80 cm–1.2 m (31 in–3.9 ft) tall and 30–45 cm (12–18 in) wide, wants full sun and moderate water, and is hardy to about -32 °C (-26 °F). Space plants about 35 cm (14 in) apart.
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Maltese cross (Jerusalem cross) at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Caryophyllaceae |
| Mature height | 80 cm–1.2 m (31 in–3.9 ft) |
| Mature spread | 30–45 cm (12–18 in) |
| Spacing | 35 cm (14 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance none |
| Soil pH | 6–8 |
| Cold hardiness | About -32 °C (-26 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 30 °C (86 °F) |
| Flowering | from about June for 5–8 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | European Russia, Central Asia and Mongolia |
| Common in gardens of | 🇷🇺 Russia, 🇬🇧 United Kingdom, 🇮🇪 Ireland, 🇩🇪 Germany, 🇵🇱 Poland, 🇸🇪 Sweden, 🇳🇴 Norway, 🇺🇸 United States, 🇨🇦 Canada |
Is Maltese cross (Jerusalem cross) toxic?
- People: mildly toxic
- Cats: mildly toxic
- Dogs: mildly toxic
- Parts: all parts
Contains saponins; eating it may upset the stomach.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Maltese cross (Jerusalem cross)
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
Questions about Maltese cross (Jerusalem cross)
- How far apart should I plant Maltese cross (Jerusalem cross)?
- About 35 cm (14 in) apart, centre to centre. A mature plant spreads 30–45 cm (12–18 in).
- Does Maltese cross (Jerusalem cross) need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Maltese cross (Jerusalem cross) need?
- Moderate water. Drought tolerance is low and waterlogging tolerance none.
- How cold-hardy is Maltese cross (Jerusalem cross)?
- It tolerates about -32 °C (-26 °F) once established, roughly USDA zone 4.
- When does Maltese cross (Jerusalem cross) flower?
- From about June for 5–8 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Maltese cross (Jerusalem cross) poisonous to cats and dogs?
- For cats it is mildly toxic; for dogs mildly toxic; for people mildly toxic. Contains saponins; eating it may upset the stomach.
- What grows well with Maltese cross (Jerusalem cross)?
- There is no well-documented companion pairing for Maltese cross (Jerusalem cross). Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society
Notes and assumptions
- Long sold as Lychnis chalcedonica. Flat heads of pure scarlet, each small flower with notched petals shaped like a cross. A very hardy old cottage plant; it may need a stake.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Sweet William Dianthus barbatus
- Carnation Dianthus caryophyllus
- China pink Dianthus chinensis
- Snow-in-summer Cerastium tomentosum
- Moss campion Silene acaulis
- Soapwort (bouncing bet) Saponaria officinalis
- Rock soapwort Saponaria ocymoides
- Creeping baby’s breath Gypsophila repens