Judas tree Cercis siliquastrum
Judas tree (Cercis siliquastrum) is a deciduous perennial tree in the Fabaceae family, native to Southern Europe and Western Asia. It grows 5–10 m (16–33 ft) tall and 5–9 m (16–30 ft) wide, wants full sun and low water, and is hardy to about -18 °C (0 °F). Space plants about 6 m (20 ft) apart.
Plan Judas tree in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Judas tree at a glance
| Type | Perennial tree, deciduous |
|---|---|
| Family | Fabaceae |
| Mature height | 5–10 m (16–33 ft) |
| Mature spread | 5–9 m (16–30 ft) |
| Spacing | 6 m (20 ft) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6–8.5 |
| Cold hardiness | About -18 °C (0 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 40 °C (104 °F) |
| Flowering | from about April for 3–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Moderate |
| Pollinator value | High |
| Edible | Yes: flowers (in salads) |
| Native to | Southern Europe and Western Asia |
| Common in gardens of | 🇬🇷 Greece, 🇮🇹 Italy, 🇪🇸 Spain, 🇹🇷 Turkey, 🇮🇱 Israel, 🇫🇷 France, 🇬🇧 United Kingdom |
Is Judas tree toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
No toxicity reported in ASPCA or standard poison references.
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 Judas tree
Good neighbours
- good With Sweet corn: "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils. Evidence C
Keep apart or take care
- caution With Alliums (onion family): Onions, garlic and leeks are said to stunt beans and peas (allium root exudates may reduce nodulation). Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Alliums (onion family): Beans and peas are traditionally kept away from onions, garlic and leeks. Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Fennel: Fennel is reported to suppress beans and peas growing next to it. Evidence C
Questions about Judas tree
- How far apart should I plant Judas tree?
- About 6 m (20 ft) apart, centre to centre. A mature plant spreads 5–9 m (16–30 ft).
- Does Judas tree need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Judas tree need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Judas tree?
- It tolerates about -18 °C (0 °F) once established, roughly USDA zone 6.
- When does Judas tree flower?
- From about April for 3–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Judas tree poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. No toxicity reported in ASPCA or standard poison references.
- What grows well with Judas tree?
- "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils.
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- RHS Plant Finder, Royal Horticultural Society
- Euro+Med PlantBase, Botanic Garden and Botanical Museum Berlin
Notes and assumptions
- Magenta pea flowers burst straight from the bare trunk and branches (cauliflory) before the leaves.
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
- Bush bean Phaseolus vulgaris
- Garden pea Pisum sativum
- Sweet pea Lathyrus odoratus
- Runner bean Phaseolus coccineus
- Broad bean (fava) Vicia faba
- Lima bean Phaseolus lunatus
- Cowpea (black-eyed pea) Vigna unguiculata
- Yardlong bean Vigna unguiculata subsp. sesquipedalis