shrub

Karo

The Story

Plant Bio

Pittosporum crassifolium, known as Karo, is a tough, leathery-leaved evergreen shrub or small tree native to coastal New Zealand. It forms a dense, wind-resistant canopy of dark green leaves backed by a thick, felt-like grey-white indumentum underneath.

The species is highly distinguished by its exceptional resistance to salt spray and shearing maritime winds, making it an ideal coastal windbreak. In spring, terminal clusters of small, bell-shaped flowers emerge in shades of deep maroon to dark purple.

Uses & Benefits:

Features dense, wind-resistant evergreen foliage with dark green leaves and contrasting silvery-white felted undersides, accented by dark maroon spring flowers.

Serves as an exceptional windbreak and salt-tolerant screen for exposed coastal and beachside gardens.

Provides nectar for bees and beneficial insects, and offers dense nesting cover for local birds.

Essentials

At a Glance

Plant Type

Shrub

Height

240"

Width

120"

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Low

Humidity

Moderate to High

Lifespan

Multi-decade

Native To

New Zealand

Toxicity

Toxic if Ingested

Bloom period

Spring – Early summer

In flower about 4 months of the year

Planting

How to Grow

Select a planting site with full sun to partial shade and excellent soil drainage.
Dig a hole twice as wide as the root ball and of equal depth, amending heavy soils with coarse sand or grit to prevent waterlogging.
Position the plant so the root crown sits level with the surrounding soil to avoid collar rot.
Water deeply to settle the soil, then establish a minimal watering schedule once the root system is established.

Pro Tip

Do not mistake the natural felted grey-white backing of the leaves for a mealybug or scale infestation; this protective indumentum is a natural feature of the plant and should not be sprayed or scrubbed off.

Keep It Thriving

Care Guide

Do

Prune lightly immediately after flowering to maintain a dense, compact shape.
Ensure the soil dries out completely between waterings to prevent root rot.
Apply a thin layer of organic compost around the base in spring to provide gentle nutrients.

Don't

Do not prune heavily into old, bare, leafless wood, as regrowth will be poor or absent.
Do not plant in low-lying areas or heavy clay soils where water pools.
Do not over-fertilize, as this species thrives in low-nutrient coastal soils.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Pest Check
Propagate
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

WindbreakHedgeCoastal GardenScreeningSpecimen Plant

Companion Plants

Ceanothus thyrsiflorus Arctostaphylos densiflora Salvia apiana

Multiply

Propagation Methods

Good to Know

Common Questions

Karo questions

What zones can Karo grow in?

Karo is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Karo deer resistant?

Not reliably. Deer may browse Karo, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Karo bloom?

Karo typically blooms in spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Karo need full sun?

Karo does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Karo drought tolerant?

Yes — once established (usually after the first full season), Karo handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.