Sunset hyssop

Sun

Full sun; flowering and winter survival are best in a warm, open position.

Water

Water regularly while establishing, allowing the soil to dry between waterings. Once established, water deeply during prolonged drought rather than little and often.

Soil

Lean, sharply drained sandy, gravelly or rocky soil. Avoid heavy clay, persistently damp ground and heavily enriched planting holes.

Height

2-3 ft (0.6-0.9 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Summer to early autumn; slender orange to salmon flowers emerge from lavender-purple calyces.

Foliage

Fine, narrow grey-green leaves with a strong licorice or root-beer scent when rubbed; usually dies back in winter.

Growth

Moderate to fast during the growing season; often flowers in its first year from an early sowing.

Care needed

Low

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

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 ft (0.3 m)

2. After 1 year

   1.6 ft (0.49 m)

3. After 2 years

   2.2 ft (0.68 m)

4. After 3 years

   2.5 ft (0.75 m)

   full size

About 2 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 in spring in colder or wetter climates so roots establish before winter.
• Let the soil dry between waterings; keep irrigation away from the crown.
• Avoid routine feeding; rich soil produces soft, floppy growth.
• Use a thin gravel mulch rather than moisture-holding organic mulch around the crown.
• Keep neighbouring plants from crowding or shading the base.

Pruning. Leave the old stems standing through winter, then cut them back to just above healthy basal growth in spring once hard frosts have passed. Remove spent flower spikes during summer if you want a tidier plant and further flowering.

Late winter

Sow seed under cover in bright conditions, pressing it onto the surface of free-draining seed compost.

Spring

Cut back old stems once new basal growth appears and hard frosts have passed.

Late spring

Plant out after the main frost risk, choosing full sun and sharply drained soil.

Summer

Water new plants during dry spells and remove spent flower spikes if desired.

Early autumn

Collect seed from dry flower spikes before it falls.

Late autumn

Leave stems standing and clear wet leaves away from the crown.

• Plant in gravel gardens with low grasses and drought-tolerant perennials for fine texture and a long season of colour.
• Repeat small groups through a sunny border with purple-flowered salvias for an orange-and-purple contrast.
• Place beside a sunny path where you can brush the scented foliage without trampling the crown.
• Use in a freely draining container with other sun-loving plants; protect the pot from prolonged winter saturation.

Garden styles it suits: Dry gravel garden, Desert / xeriscape, Southwestern, Pollinator garden, Sensory garden and Hot border.

Plant it with: Lavender, Russian sage, Yarrow, Blanket flower, Blue grama and Pineleaf penstemon.

Wildlife: Flowers attract bees and butterflies, and hummingbirds where these occur in the Americas. The aromatic foliage is often avoided by deer and rabbits, although browsing is still possible.

• Winter crown and root rot: improve drainage, keep wet mulch away from the base and avoid low spots where water collects.
• Floppy stems and sparse flowering: move to full sun, stop feeding and reduce unnecessary watering.
• Spider mites in hot, dry conditions: inspect leaves for fine stippling and webbing, then rinse leaf undersides while avoiding repeated soaking of the crown.
• Slugs and snails damaging spring shoots: check emerging growth and use hand-picking or suitable barriers.

Not known to be toxic to people, cats, dogs or horses. Species-specific safety information is limited, and no part should be assumed safe to eat solely because it is aromatic.

• Texas hummingbird mint (Agastache cana)

  Usually has rose-pink flowers and broader, more triangular grey-green leaves rather than the very narrow leaves and orange flowers of sunset hyssop.

• Orange hummingbird mint (Agastache aurantiaca)

  Also bears orange flowers, but its leaves are generally broader and more oval; sunset hyssop has a distinctly fine, almost threadlike foliage texture.

The species name rupestris means growing among rocks, referring to its rocky native habitat.

Propagation. Grow from seed sown under cover in late winter or spring; surface-sow because light aids germination. Take softwood cuttings from healthy, non-flowering shoots in late spring or early summer.

Accepted botanical name

Agastache rupestris

In the US and Canada

Native in the lower 48 states.

Native range

Arizona and New Mexico.

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