Pittosporum crassifolium (Karo)

Pittosporum crassifolium: How to Grow Karo, the Coastal Evergreen Pittosporum

Pittosporum crassifolium, commonly called karo, caro, evergreen pittosporum, parchment bark, or New Zealand pittosporum, is a dense evergreen shrub or small tree grown for coastal hedges, windbreaks, privacy screens, and handsome silver-backed foliage. Native to New Zealand, it is especially useful in mild seaside gardens where wind, salt exposure, and year-round structure matter.

Karo has a quiet, architectural beauty. Its thick oval leaves are grey-green above and softly felted white to grey beneath, creating a silver flicker when wind moves through the branches. In spring, small fragrant flowers open in deep red, maroon, or purple shades, followed by woody capsules that split to reveal black seeds in sticky yellow pulp.

Quick Facts – Pittosporum crassifolium

Use: Coastal screens, evergreen hedges, privacy planting, windbreaks, foundation planting, wildlife-friendly borders, and New Zealand or Mediterranean-style gardens.
Highlight: Thick grey-green leaves with pale felted undersides, fragrant dark red to purple spring flowers, and strong coastal tolerance.
Best conditions: Mild climate, full sun to partial shade, free-draining soil, and protection from hard frost.

Botanical Name	Pittosporum crassifolium
Family	Pittosporaceae
Common Names	Karo, caro, evergreen pittosporum, parchment bark, New Zealand pittosporum
Native Range	New Zealand, especially northern coastal regions; naturalized or self-sown in some other mild areas
Plant Type	Evergreen shrub or small tree
Hardiness	Best in mild coastal climates; often suitable for USDA Zones 9-11 or equivalent mild-climate gardens
Height	Often maintained at 8-12 ft.; taller if unpruned in suitable climates
Spread	Usually 6-10 ft. wide in gardens; wider with age if unpruned
Sun Exposure	Full sun to partial shade
Soil	Well-drained sand, loam, gravelly, chalky, acidic, neutral, or mildly alkaline soil
Bloom Time	Spring
Flower Color	Deep red, maroon, purple, or reddish-purple
Water Needs	Regular while young; low to moderate once established
Wildlife Value	Flowers attract pollinators; birds disperse the sticky seeds
Pet and Child Safety	Ornamental, not edible; discourage chewing of leaves, flowers, fruit, or seeds

Care – Quick

• Planting: Plant in spring, or in fall where winters are mild.
• Light: Choose full sun for dense growth; use partial shade in hot inland gardens.
• Water: Water regularly during establishment, then deeply during long dry periods.
• Soil: Prioritize drainage. Avoid compacted ground and waterlogged clay.
• Feeding: Feed lightly in spring only if growth is weak.
• Pruning: Trim after flowering or during active growth to shape hedges and screens.

Best For / Avoid Where

Best For

• Mild coastal gardens and salt-wind exposure.
• Evergreen hedges, privacy screens, and windbreaks.
• Well-drained soils with low to moderate summer water.
• Silver-green contrast in foliage-focused designs.

Avoid Where

• Hard freezes are common.
• Soil stays wet through winter.
• Deep shade causes thin, open growth.
• Natural areas are vulnerable to self-sown seedlings.

What Is Pittosporum crassifolium?

Pittosporum crassifolium is a bushy evergreen shrub or small tree in the Pittosporaceae family. The species name crassifolium refers to its thick leaves, one of the plant’s easiest identification features. The foliage is leathery, oval to oblong, grey-green on top, and white to grey-felted underneath.

In gardens, karo is valued more for structure than for a large flower display. It can be clipped as a hedge, grown as a dense privacy screen, shaped near foundations, or allowed to mature as a small multi-stemmed tree. The pale leaf undersides, scented spring flowers, and tolerance of exposed seaside conditions make it especially useful where softer evergreen shrubs struggle.

Key Identification Features

• Leaves: Thick, leathery, oval to oblong, grey-green above, and pale felted beneath.
• Flowers: Small, fragrant, five-petaled blooms in deep red, maroon, purple, or reddish-purple shades.
• Fruit: Rounded woody capsules that split open to show black seeds in sticky yellow pulp.
• Habit: Dense, rounded evergreen shrub or small tree with strong screening value.
• Texture: Silver-green foliage effect, especially visible in wind.

Native Range

Pittosporum crassifolium is endemic to New Zealand, where it is associated with northern coastal regions, forest margins, cliffs, rocky places, and exposed seaside habitats. In some regions outside its original range, it can naturalize because birds disperse the sticky seeds.

Bloom Time and Seasonal Interest

Karo flowers in spring. The blooms are small but fragrant, appearing among the evergreen foliage in dark red to purple tones. The leaves remain attractive all year, and mature plants may also carry fuzzy woody capsules that split into sections when ripe.

How Big Does Pittosporum crassifolium Get?

In many gardens, karo is kept about 8-12 feet tall and 6-10 feet wide with pruning. In mild climates with space and little pruning, it can become taller and more tree-like. For hedges, plan on regular trimming; for a natural screen, allow enough room for its rounded habit.

Hardiness

Karo is best suited to mild gardens, especially coastal areas where winter extremes are softened by maritime influence. Established plants may tolerate moderate frost, but exposed inland sites, hard freezes, cold wet soil, and frost pockets can cause damage. In marginal climates, grow it against a warm wall, in a protected courtyard, or in a large container that can be sheltered during severe cold.

Where to Use Karo in the Landscape

Use Pittosporum crassifolium where you need a durable evergreen shrub that provides year-round cover and handles exposed, well-drained sites. It is especially effective beside driveways, paths, terraces, boundary lines, and seaside garden edges.

• Coastal screens: Plant as a wind-filtering evergreen barrier in mild seaside gardens. Best Plants for Windy Coastal Gardens
• Hedges: Clip lightly and regularly to maintain a dense formal or semi-formal hedge.
• Privacy planting: Allow a looser, taller form where year-round coverage is needed.
• Foundation planting: Use where a tough evergreen shrub is needed, provided there is enough room.
• Wildlife-friendly gardens: Pair with other flowering shrubs and perennials to extend nectar availability.
• New Zealand-style gardens: Combine with flax, sedges, mat rush, astelia, and other bold foliage plants.

Wildlife Value

The fragrant spring flowers are useful to pollinators, while birds can disperse the seeds after the capsules ripen. In a wildlife-friendly garden, karo works best as evergreen structure combined with nectar-rich plants that flower before and after its spring bloom.

Deer and Rabbits

Karo is not usually among the first plants browsed because its leaves are thick, leathery, and somewhat aromatic. However, browsing pressure varies widely. Protect young plants where deer or rabbits are common, especially during drought or winter scarcity.

Toxicity and Safety

Karo is grown as an ornamental plant, not an edible hedge or medicinal plant. Keep pets and children from chewing leaves, flowers, seed capsules, or seeds. Do not use homemade preparations unless guided by a qualified expert and correct plant identification.

Invasiveness and Self-Sowing

Karo can self-sow where conditions suit it, especially in mild climates where birds distribute the seeds. Outside its native range, check local invasive-plant guidance before planting near bushland, coastal reserves, or other sensitive natural areas. Remove unwanted seedlings early.

How to Grow Pittosporum crassifolium

Light

• Best: Full sun for dense growth, strong foliage color, and good flowering.
• Tolerates: Partial shade, especially in hot or reflective gardens.
• Avoid: Deep shade, which can produce sparse growth and fewer flowers.

Soil

• Drainage: Well-drained soil is essential.
• Texture: Sandy, loamy, chalky, gravelly, or lightly amended soils can work.
• pH: Tolerates acidic, neutral, and mildly alkaline conditions.
• Avoid: Waterlogged clay, compacted soil, and sites that stay cold and wet in winter.

Suggested Spacing

Spacing depends on climate, soil, pruning style, and the size of the plants at installation. Plant closer for a clipped hedge and farther apart for a natural screen. Avoid crowding karo tightly against walls, paths, or foundations unless you are prepared to prune regularly.

Water

Water young plants regularly through the first growing season so they establish a strong root system. Once established, karo usually needs only occasional deep watering during long dry spells. Container-grown plants dry faster than plants in the ground and need closer attention during warm or windy weather.

Feeding

Karo is not a heavy feeder. In average garden soil, it often needs little more than compost or organic mulch. If growth is weak, apply a balanced slow-release fertilizer in spring. Avoid excess nitrogen, which can encourage soft, pest-prone growth.

Mulch

Apply a light mulch of bark, compost, leaf mold, or gravel to reduce weeds and conserve moisture. Keep mulch away from the trunk and lower stems so the crown does not stay damp.

Pruning and Maintenance

When to Prune

Prune after flowering or during active growth to shape the plant, remove damaged stems, and keep hedges dense. Light, regular trimming is better than severe renovation. For screens, shorten long shoots to encourage branching and maintain fullness from base to top.

How to Keep a Hedge Dense

• Start shaping while plants are young rather than waiting until they are overgrown.
• Trim the sides lightly to encourage branching.
• Keep the top slightly narrower than the base so light reaches the lower foliage.
• Avoid repeated hard cuts into old, bare wood unless renovation is unavoidable.

What Not to Do

Do not plant karo in a very narrow strip and expect it to stay compact without pruning. Avoid overwatering in heavy soil, overfeeding with high-nitrogen fertilizer, or allowing a hedge to become top-heavy and shaded at the base.

Growing in a Pot

Karo can be grown in a large container in mild climates. Choose a sturdy pot with drainage holes and use a free-draining, loam-based potting mix. Place it in sun or light shade, water consistently while young, and prune to keep the plant in proportion with the container. In cold regions, move potted plants to a sheltered position before severe frost.

How to Propagate Pittosporum crassifolium

Karo can be grown from fresh seed, and seedlings may appear naturally where birds disperse ripe seed. For named selections, compact forms, or plants chosen for a particular habit or foliage quality, semi-hardwood cuttings are preferred because they preserve the parent plant’s characteristics. Take cuttings from healthy, non-flowering shoots and root them in a free-draining propagation mix.

Where Pittosporum crassifolium Struggles

Karo is resilient in the right setting but less forgiving in cold, wet, or stagnant conditions. Yellowing leaves often point to root stress, poor drainage, overwatering, nutrient imbalance, or cold damage. Thin growth usually indicates too much shade, crowding, or a hedge that was not shaped early enough.

Seasonality and Timing

Common Problems, Pests, and Diseases

Healthy karo plants in suitable sites are generally low maintenance. Problems are more likely when plants are stressed by poor drainage, cold damage, drought, overcrowding, or excessive feeding.

Aphids

Aphids may cluster on soft new shoots. Encourage beneficial insects, avoid overfeeding, and wash small colonies from the plant with water.

Scale Insects

Scale insects, including cushion scale in some regions, may appear on stressed or congested plants. Improve airflow, prune crowded growth, and inspect stems and leaf undersides.

Spider Mites

Spider mites can develop in hot, dry, sheltered places. Reduce stress with deep watering during drought and periodically rinse dusty foliage.

Pittosporum Sucker

In some regions, pittosporum sucker can distort new growth on susceptible plants. Prune out badly affected tips, support steady growth, and avoid heavy nitrogen feeding that encourages soft flushes.

Powdery Mildew and Leaf Spot

Powdery mildew and leaf spot are more likely where airflow is poor or foliage stays damp. Space plants properly, avoid overhead irrigation late in the day, and remove heavily affected leaves.

Design Ideas for Pittosporum crassifolium

Use karo as a calm evergreen framework plant rather than a short-term flowering feature. Its silver-backed leaves, dark spring flowers, and dense habit make it valuable in gardens that rely on foliage, texture, and year-round form.

• For a coastal screen: Plant in a staggered row and prune lightly to build density.
• For silver-green contrast: Pair with dark phormium, bronze sedges, or burgundy foliage.
• For a New Zealand-style border: Combine with flax, lomandra, astelia, and carex.
• For low-maintenance structure: Use behind perennials or smaller shrubs as an evergreen backbone.
• For wildlife value: Add long-flowering companion plants so nectar is available across more seasons.

Best Companion Plants

Choose companions that like mild climates, sun to light shade, good drainage, and coastal exposure.

• Phormium tenax – New Zealand Flax – Bold sword-like foliage creates strong architectural contrast beside karo’s rounded evergreen mass.
• Carex testacea – New Zealand Hair Sedge – Warm coppery foliage softens the base of evergreen screens.
• Lomandra longifolia – Spiny-headed Mat Rush – A tough grassy evergreen for coastal gardens, slopes, and low-water plantings.
• Westringia fruticosa – Coast Rosemary – A salt-tolerant shrub with soft grey foliage and small pale flowers.
• Banksia integrifolia – Coast Banksia – A bold coastal tree or large shrub for full sun, wildlife value, and evergreen structure.
• Carpobrotus rossii – Karkalla – A spreading succulent ground cover for sunny coastal banks and sandy soils.

Pittosporum crassifolium vs. Similar Pittosporums

Frequently Asked Questions

Sources and References

• Royal Horticultural Society – Pittosporum crassifolium
• New Zealand Plant Conservation Network – Pittosporum crassifolium
• San Marcos Growers – Pittosporum crassifolium
• Gardenia – Coastal Garden Plant Combination Ideas

Updated: May 2026 • Reviewed by Gardenia Editors