Flame acanthus

Sun

Full sun for the strongest flowering; tolerates light partial shade.

Water

Low once established; water regularly during establishment, then deeply during prolonged dry spells.

Soil

Well-drained sandy, gravelly or loamy soil; tolerates limestone and clay provided water does not linger around the roots.

Height

3-5 ft (0.9-1.5 m)

Spread

3-4 ft (0.9-1.2 m)

Flowers

Summer through autumn, often until frost; narrow tubular flowers in orange to orange-red.

Foliage

Small, opposite, narrow green leaves on slender, twiggy stems; deciduous, sometimes dropping leaves during severe drought.

Growth

Moderate to fast in warm weather.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.2 ft (0.68 m)

3. After 2 years

   2.8 ft (0.85 m)

4. After 3 years

   3 ft (1 m)

5. After 5 years

   4 ft (1.2 m)

   full size

About 4 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the US

Growth rate

Fast

• Plant after hard frosts have passed, allowing room for its spreading branches.
• Water deeply through the first growing season, letting the soil dry somewhat between waterings.
• Once established, give occasional deep water during extended drought to support flowering.
• Avoid rich feeding; most garden soils need no additional fertiliser.
• Apply a light mulch over the root zone, keeping it clear of the woody base.

Pruning. In late winter or early spring, remove dead wood and shorten live stems to maintain a compact framework. Where frost kills the top growth, cut dead stems close to the ground before new shoots develop; flowering occurs on new growth.

Late winter

Inspect for winter damage and prune before new growth begins.

Spring

Plant after hard frosts and water new plants thoroughly.

Late spring

Check for shoots from the base before assuming a frost-damaged plant has died.

Summer

Water established plants deeply during prolonged dry weather rather than giving frequent light sprinklings.

Autumn

Remove unwanted seedlings and avoid heavy pruning before winter.

Winter

Keep the root zone free of standing water, especially near the colder limit of its range.

• Plant in a sunny mixed border with ornamental grasses and salvias for a long season of warm colour.
• Use in gravel gardens with yuccas and other dryland plants, where its loose branches soften rigid forms.
• Group along a sunny fence or informal boundary as a low, flowering screen.
• Place near a seating area or window to watch hummingbirds in the Americas and visiting insects elsewhere.

Garden styles it suits: Desert / xeriscape, Southwestern, Texas Hill Country, Wildlife garden, Dry gravel garden and Hot border.

Plant it with: Autumn sage, Red yucca, Lindheimer's muhly, Blackfoot daisy, Purple coneflower and Butterfly weed.

Wildlife: Tubular flowers are especially attractive to hummingbirds in their range and are also visited by butterflies and other insects. Deer often leave it alone, though browsing is still possible.

• Root rot or winter loss in wet soil: improve drainage or move the plant to a raised, freely draining position.
• Winter dieback: leave the roots undisturbed and wait for warm-weather regrowth before removing the plant.
• Sparse flowering and floppy growth in shade: move to a sunnier position and avoid high-nitrogen feeding.
• Unwanted seedlings: pull them while small or remove developing seed capsules before they split.

Not known to be toxic to people, cats, dogs or horses, but species-specific safety information is limited. No particular plant part is established as poisonous; it is not an edible plant, so discourage ingestion.

• Chuparosa (Justicia californica)

  Chuparosa has conspicuously green stems, generally broader leaves and red tubular flowers with a more obvious lower lip; it often flowers on nearly leafless branches.

• Thurber's desert honeysuckle (Anisacanthus thurberi)

  A close relative with generally longer, broader leaves and more muted orange to reddish flowers. Flowers overlap in appearance, so use a reliable nursery label or regional botanical key for a firm identification.

The common name flame acanthus refers to its flame-coloured orange-red flowers.

Propagation. Sow ripe seed in spring in a warm, well-drained seed mix, or take softwood cuttings in late spring to early summer. Garden seedlings may appear near established plants.

Accepted botanical name

Anisacanthus quadrifidus

In the US and Canada

Native in the lower 48 states.

Native range

Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southeast, Mexico Southwest and Texas.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.