Purple toadflax Linaria purpurea
Purple toadflax (Linaria purpurea) is a deciduous perennial flowering plant in the Plantaginaceae family, native to Italy and Sicily. It grows 50–90 cm (20–35 in) tall and 25–35 cm (10–14 in) wide, wants full sun and low water, and is hardy to about -20 °C (-4 °F). Space plants about 30 cm (12 in) apart.
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Purple toadflax at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Plantaginaceae |
| Mature height | 50–90 cm (20–35 in) |
| Mature spread | 25–35 cm (10–14 in) |
| Spacing | 30 cm (12 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance moderate, waterlogging tolerance none |
| Soil pH | 6–8.5 |
| Cold hardiness | About -20 °C (-4 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 34 °C (93 °F) |
| Flowering | from about June for 11–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Italy and Sicily |
| Common in gardens of | 🇬🇧 United Kingdom, 🇮🇪 Ireland, 🇮🇹 Italy, 🇫🇷 France, 🇩🇪 Germany, 🇳🇿 New Zealand, 🇺🇸 United States |
Is Purple toadflax toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Not known to be poisonous.
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 Purple toadflax
No well-documented helpful pairing. Group it with plants that like full sun and low water.
Questions about Purple toadflax
- How far apart should I plant Purple toadflax?
- About 30 cm (12 in) apart, centre to centre. A mature plant spreads 25–35 cm (10–14 in).
- Does Purple toadflax need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Purple toadflax need?
- Low water. Drought tolerance is moderate and waterlogging tolerance none.
- How cold-hardy is Purple toadflax?
- It tolerates about -20 °C (-4 °F) once established, roughly USDA zone 6.
- When does Purple toadflax flower?
- From about June for 11–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Purple toadflax 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. Not known to be poisonous.
- What grows well with Purple toadflax?
- There is no well-documented companion pairing for Purple toadflax. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society
- Euro+Med PlantBase, Botanic Garden and Botanical Museum Berlin
Notes and assumptions
- Narrow grey-green leaves and slim spikes of tiny snapdragon flowers, adored by bees. Long grown in Britain and now wild on old walls; the pink form ‘Canon Went’ comes true from seed.
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
- Foxglove Digitalis purpurea
- Snapdragon Antirrhinum majus
- Penstemon (beardtongue) Penstemon digitalis
- Hebe Veronica speciosa
- Fairy foxglove Erinus alpinus
- Parry's penstemon Penstemon parryi
- Rice paddy herb (ngò om) Limnophila aromatica
- Angelonia (summer snapdragon) Angelonia angustifolia