New Zealand flax
Hardiness varies noticeably by cultivar in this genus more than most others in this KB — check the specific variety before assuming it will survive a hard UK winter outdoors, and in colder gardens, grow less hardy cultivars in a container that can be moved to shelter.
Care
Tolerates some part shade, but leaf colour is strongest and growth most compact in full sun.
Regular watering while establishing; reasonably drought-tolerant once well rooted, though appreciates water in prolonged dry spells.
Free-draining soil of most types; dislikes sitting wet over winter more than it dislikes poor or dry soil.
Remove dead, damaged or scruffy leaves at the base by cutting or pulling them away close to the crown; cut out flower spikes once finished if a tidier look is wanted.
One balanced feed in spring, and a slow-release feed for a container plant. On rich soil it grows very large very quickly, which is usually a problem rather than a benefit in a small garden.
Divide the clump in spring, cutting down through the crown with a spade — it is heavy, tough work and each piece needs several fans and roots. Cut the leaves back by half to reduce wind-rock while it re-establishes.
Month by month
Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.
- MarchAssess winter damage once new growth is clearly underway — resist cutting back too early, as apparently dead leaves sometimes still protect the crown from further cold. how ›
- AprilRemove any leaves damaged over winter, cutting close to the base. how ›
- NovemberIn colder gardens or a hard winter forecast, protect the crown with a dry mulch; some cultivars are noticeably less hardy than others. how ›
Months based on climate: UK. Your choice stays on this device.
- MarchAssess winter damage once new growth is clearly underway — resist cutting back too early, as apparently dead leaves sometimes still protect the crown from further cold. how ›
- AprilRemove any leaves damaged over winter, cutting close to the base. how ›
- NovemberIn colder gardens or a hard winter forecast, protect the crown with a dry mulch; some cultivars are noticeably less hardy than others. how ›
Months based on climate: Northern Italy. Your choice stays on this device.
- FebruaryAssess winter damage once new growth is clearly underway — resist cutting back too early, as apparently dead leaves sometimes still protect the crown from further cold. how ›
- MarchRemove any leaves damaged over winter, cutting close to the base. how ›
- NovemberIn colder gardens or a hard winter forecast, protect the crown with a dry mulch; some cultivars are noticeably less hardy than others. how ›
Months based on climate: Central Italy. Your choice stays on this device.
- FebruaryAssess winter damage once new growth is clearly underway — resist cutting back too early, as apparently dead leaves sometimes still protect the crown from further cold. how ›
- MarchRemove any leaves damaged over winter, cutting close to the base. how ›
- DecemberIn colder gardens or a hard winter forecast, protect the crown with a dry mulch; some cultivars are noticeably less hardy than others. how ›
Months based on climate: Southern Italy and islands. Your choice stays on this device.
Common problems
How to spot it. Mushy, blackened crown, or the whole plant failing to resprout in spring.
What to do. Hardiness varies considerably by cultivar — some tolerate UK winters reliably, others are considerably more tender; in cold gardens, choose a hardier cultivar and mulch the crown over winter, especially while young.
How to spot it. Browned, tattered leaf tips or whole damaged leaves after cold or windy weather.
What to do. Remove damaged leaves close to the base once new growth is clearly underway in spring — cutting too early, before the worst of winter has passed, removes leaves that may still be protecting the crown.
How to spot it. Thin, less colourful growth compared to a plant in full sun.
What to do. This genus performs best in full sun — move container-grown plants to a sunnier spot, or expect a less architectural, less colourful result in shade.
Popular varieties
Questions
New Zealand flax: is it hardy?
H5: Hardy in most of the UK, but can struggle in the coldest inland or upland spots. It survives down to −15 °C.
Can it grow in a pot?
Does very well in a large container, which also makes it easier to move a tender cultivar somewhere sheltered for winter in a cold garden.
New Zealand flax: when do you prune it?
Remove dead, damaged or scruffy leaves at the base by cutting or pulling them away close to the crown; cut out flower spikes once finished if a tidier look is wanted.
New Zealand flax: when does it flower?
In the climate of UK it flowers in June–July.
When do you feed it?
One balanced feed in spring, and a slow-release feed for a container plant. On rich soil it grows very large very quickly, which is usually a problem rather than a benefit in a small garden. Feeding months, UK: April.