Buy Agastache Plants — Fragrant Perennials for Australian Gardens

Agastache (also known as hyssop, anise hyssop, or giant hyssop) are among the most rewarding perennials you can grow in an Australian garden. These long-lived, low-maintenance plants produce tall, architectural spikes of densely packed tubular flowers from spring through to late autumn — in shades of deep violet-blue, raspberry, orange, apricot, and coral pink.

At Online Plants, our horticulturists have carefully selected varieties proven to perform across Australian climate zones. Whether you garden in Melbourne's temperate conditions, Sydney's humid subtropics, Adelaide's dry Mediterranean summers, or Brisbane's warm climate, there is an Agastache variety suited to your garden.

Why Australian Gardeners Love Agastache

Exceptional drought tolerance. Once established — usually within four to six weeks of planting — Agastache require minimal watering. They are built for Australian summers, thriving in heat and well-drained soils where many other perennials struggle. This makes them one of the most water-wise choices for a sustainable Australian garden.

Long flowering season. Few perennials match Agastache for sheer flowering duration. Blooms appear from late spring and continue well into autumn — often four to five months of continuous colour. Regular deadheading throughout the season encourages even more blooms.

Fragrant foliage. Crush a leaf and you'll discover a delightful aniseed-mint fragrance. Plant Agastache along garden paths and borders where you'll brush past them daily. The aromatic foliage also acts as a natural deterrent to deer and rabbits.

Edible flowers and leaves. Both the flowers and leaves of Agastache are edible. The leaves carry a sweet aniseed flavour and can be brewed as an herbal tea, added fresh to salads, or used to infuse syrups and dressings. The vivid flower spikes make a stunning, edible garnish for summer dishes and cocktails.

A magnet for native Australian wildlife. Agastache are exceptional pollinator plants. In Australian gardens they attract native blue-banded bees, honey bees, butterflies, and — especially in eastern Australia — nectar-feeding honeyeaters. If building a wildlife-friendly or pollinator garden, Agastache are an essential inclusion.

Frost tolerant and versatile. Most varieties are frost hardy to -10°C or below when established, making them well-suited to cool-climate gardens in Victoria, the ACT, highland NSW, and Tasmania. They grow equally well as feature plants, mass-planted in borders, or in pots and containers on a sunny patio.

How to Grow Agastache in Australia

Soil and Position Agastache perform best in a full-sun position receiving at least six hours of direct sun daily. They tolerate light afternoon shade, particularly in warmer climates, but reduced sun generally means fewer flowers. Choose a well-draining soil — Agastache will rot in waterlogged conditions. Sandy loams and loamy soils suit them well. In heavy clay soils, raise the bed or improve drainage with gypsum and organic matter before planting.

Avoid over-fertilising. Agastache actually prefer relatively lean soil. Excess nitrogen produces lush, floppy growth with fewer flowers and reduces the concentration of essential oils in the foliage. A light application of slow-release fertiliser at planting time, and again in early spring, is usually sufficient.

When to Plant The best time to plant Agastache in Australia is spring (September to November) once the risk of frost has passed in your area, or autumn (March to May) in frost-free climates. Spring planting allows time for roots to establish before summer heat; autumn planting in warmer regions gives plants a full season head-start before their first summer.

Watering Water regularly for the first four to six weeks after planting to assist establishment. Once established, Agastache are remarkably self-sufficient — water only during extended dry periods or extreme heat events. Overwatering is a common mistake; always allow the soil to partially dry between waterings.

Pruning and Maintenance Deadhead spent flower spikes regularly throughout the season to extend blooming. At the end of the flowering season, cut plants back to around 10–15 cm above ground level. In cooler climates, this hard prune is best done in late autumn after flowering finishes. In frost-free regions, a light tidy in late winter or early spring as new growth emerges is sufficient. Every three to five years, divide established clumps in spring to rejuvenate them, replanting the vigorous outer sections.

Pot and Container Growing Agastache grow well in containers — ideal for apartment balconies, courtyards, and patio gardens. Choose a pot with excellent drainage holes and use a quality, well-draining potting mix. Position in full sun. Container plants dry out faster than garden-grown plants and will need more frequent watering, particularly in summer. Feed monthly with a diluted liquid fertiliser to replenish nutrients.

Varieties We Stock

Online Plants stocks an extensive range of Agastache varieties. Current stock includes:

Agastache Blue Fortun — One of the most popular and widely grown varieties. Produces dense spikes of smoky violet-blue flowers on sturdy stems to 90 cm. Exceptional for attracting native bees. Hardy and long-lived.
Agastache Black Adder — Dark, brooding blue-purple flower spikes with near-black calyxes. Striking in cottage gardens and pollinator borders. Grows to around 90 cm.
Agastache Little Adder — A compact form ideal for smaller gardens or container growing. Produces the same deep blue-purple flower spikes as Black Adder but in a neater, more manageable habit.
Agastache Raspberry — Bold raspberry-red flower spikes that provide vivid contrast against grey and silver foliage plants. A showstopper in the summer border.
Agastache Orange — Warm terracotta-orange flower spikes with a lively, tropical energy. Stunning combined with ornamental grasses and yellow-foliaged plants.

Browse our full range of currently available varieties in the product listings above. Stock is seasonal — contact our team if you are looking for a specific variety.

Where to Use Agastache

Cottage Garden Borders: Agastache are a quintessential cottage garden plant. Their tall flower spikes work beautifully alongside lavender, salvia, echinacea, catmint (Nepeta), and ornamental grasses. The vertical form of Agastache provides essential structure and height variation in mixed perennial beds.

Dry and Water-Wise Gardens: If water efficiency is a priority, Agastache are among the best choices available. Combine with other drought-tolerant perennials such as Russian Sage (Perovskia), Salvia, Stachys, and Achillea for a vibrant, low-water garden that looks stunning all summer.

Pollinator and Wildlife Gardens: Plant Agastache in drifts of three to five plants to maximise impact for visiting insects and birds. Pair with other pollinator favourites — lavender, borage, phacelia, and native grasses — to create a habitat garden that buzzes with activity from spring to autumn.

Cut Flower Gardens: Agastache flower spikes are excellent cut flowers. They hold their colour and structure well in a vase, and their fragrance fills a room. Combine with dahlias, rudbeckia, and ornamental grasses for relaxed, naturalistic arrangements.

Pots and Containers: Compact varieties such as 'Little Adder' are perfectly suited to containers. Plant in a large pot with lavender and trailing herbs for a fragrant, drought-tolerant potted display.

FAQ - Frequently Asked Questions

Are Agastache plants perennial in Australia?

Yes. Agastache are perennial in most parts of Australia. In cool-temperate climates (Melbourne, Canberra, highland areas of NSW and Victoria), they may die back to the ground in winter but re-shoot vigorously in spring. In frost-free subtropical and tropical climates, many varieties remain semi-evergreen year-round.

How long do Agastache plants live?

Agastache are genuinely long-lived perennials when given well-draining soil and a sunny position. Individual plants commonly live for five to ten years. Clumps can be divided every three to five years to rejuvenate them and extend their productive life further.

Are Agastache suitable for Perth and Western Australia?

Yes, with care. Agastache generally perform well in Perth's Mediterranean climate — the combination of dry summers and mild winters suits them well. Plant in well-draining soil, full sun, and water to establish. Once established they are well-adapted to Perth's dry summer conditions.

Are Agastache plants deer and rabbit resistant?

Yes. The strongly aromatic foliage of Agastache is generally unpalatable to deer and rabbits, making them a good choice for gardens in rural and semi-rural areas where wildlife pressure on plants can be challenging.

Can I grow Agastache from seed in Australia?

Yes. Agastache can be grown from seed, though germination is sometimes slow and irregular. For best results, sow seed in trays at a soil temperature of 18–22°C in spring. Most gardeners find it faster and more reliable to start with nursery-grown plants — you will also be sure of the variety and flower colour you are buying.