Garden hybrid

This is a garden hybrid, bred from more than one wild species, so it has no single species page of its own.

4 other cultivars

shrub

Harkness Bottlebrush

Callistemon x hybrida 'Harkness'

The Story

Plant Bio

Callistemon species are evergreen Australian woody plants characterized by their dense, cylindrical flower spikes composed of prominent, colorful stamens. These plants produce narrow, leathery leaves and woody seed capsules that remain tightly clustered along the branches for multiple seasons.

'Harkness' is a vigorous hybrid cultivar that forms a large shrub or small tree with a gracefully semi-weeping branch habit. It produces bright, deep red flower spikes up to six inches long during spring and fall, complemented by lance-shaped emerald leaves.

Uses & Benefits:

Features large, weeping branches adorned with bright red, brush-like flower spikes and narrow emerald foliage.

Functions as an effective windbreak, privacy screen, or low-maintenance hedge once established.

Provides abundant nectar for hummingbirds, bees, and butterflies in North American gardens.

Garden hybrid

Bred from more than one wild species, so it has no species page of its own.

Essentials

At a Glance

Plant Type

Shrub

Height

197"

Width

157"

Light

Full Sun, Partial Sun

Zones

8, 9, 10

Water

Low to Moderate

Humidity

Medium

Lifespan

Long-lived

Native To

Australia

Toxicity

Non-toxic

Bloom period

Spring – Fall

In flower about 9 months of the year

Planting

How to Grow

Select a planting site in full sun to partial shade with well-drained soil.
Dig a hole twice as wide as the root ball and of equal depth, ensuring the crown sits level with the surrounding soil.
Water deeply and regularly during the first growing season to establish a deep root system.
Apply a thin layer of organic mulch around the base to retain moisture, keeping it clear of the main trunk.

Pro Tip

Prune immediately after the spring flowering flush, leaving some green foliage on each branch; cutting back into old, bare wood prevents reliable bud regeneration.

Keep It Thriving

Care Guide

Do

Prune lightly right after the main spring bloom to maintain a dense, bushy form.
Ensure the soil drains freely to prevent root rot pathogens.
Water thoroughly during extended dry spells once established.

Don't

Do not prune deeply into old, leafless wood as it will fail to shoot back.
Avoid applying high-phosphorus fertilizers which can damage the root system.
Do not allow the soil to become waterlogged or sit in standing water.

Seasonal Care Calendar

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

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Privacy ScreenSpecimen PlantingHedgeWindbreak

Companion Plants

Westringia fruticosa Salvia clevelandii Lomandra longifolia

Multiply

Propagation Methods

Good to Know

Common Questions

Harkness Bottlebrush questions

What zones can Harkness Bottlebrush grow in?

Harkness Bottlebrush is hardy in USDA Zones 8–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Harkness Bottlebrush deer resistant?

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

When does Harkness Bottlebrush bloom?

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

Does Harkness Bottlebrush need full sun?

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

Is Harkness Bottlebrush drought tolerant?

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