New Zealand Flax
Phormium tenax
Stiff upright leaves that are pulled away rather than cut, on a plant that shrugs off drought but not a winter spent in wet ground.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun through to partial shade.
- Watering
- Moderate watering; drought-tolerant once established.
- Feeding
- A light feed in spring.
- Frost tolerant
- Yes
- Flowering
- June
- Pruning
- Pull the dead leaves away rather than cutting them, and tidy the flower spikes once they finish.
- Overwintering
- Only half-hardy; protect colored cultivars in cold gardens.
- Mar–Jun Spring Growth
- Jun–Sep Flowering
- Sep–Dec Growing
- Jan–Mar Growing
- Plant spacing
- 4 ft 11 in
- In-row spacing
- 4 ft 11 in
- Between rows
- 6 ft 2 in
- Square-foot density
- Not suited to SFG
- Root system
- A dense fibrous mat
- Working depth
- 8–24 in
- Can reach
- 5 ft down where the soil allows
- Spread
- 5–10 ft across, about 1–2× the width of the plant
- Shallowest pot
- 12 in of soil
Thousands of fine roots knit the top of the soil into a turf, which is what holds a bank together and what makes an established clump so hard to lift. Prairie grasses send a few roots far below the mat as well.
A thick, tough mass of roots and a fan-shaped crown that widens every year, and an established New Zealand flax is one of the hardest clumps in the garden to dig out. Site it as a permanent plant and divide it with a saw.
The habit is New Zealand Flax’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Green lacewing Chrysoperla carneaHunts Mealybugs
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Hoverfly SyrphidaeHunts Mealybugs
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Ladybird (lady beetle) CoccinellidaeHunts Mealybugs
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
Green-leaved shrubs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com