Agastache foeniculum Seeds | Anise Hyssop
LATIN NAME: Agastache foeniculum
COMMON NAME: Anise Hyssop
Plant Profile
Anise hyssop is an upright herbaceous perennial of the mint family, sixty to a hundred and twenty centimetres tall, with square stems, opposite leaves and a bushy, well-branched habit. The leaves are ovate, toothed, soft grey-green beneath and bright green above, and they carry a strong, sweet scent of anise or of root beer that is unmistakable once you have met it.
The flowers are the second reason it is grown. They are small, tubular, lavender-blue to violet, and they are packed into dense, cylindrical spikes at the top of the stems, opening from the bottom upward over a long period from midsummer into autumn. A plant in full flower hums with bees, and it is one of the most reliable pollinator plants in a temperate garden.
The foliage and the flower spikes both carry the scent, and the leaves keep it when dried, which is why the plant is grown as a herbal tea and as a culinary herb as well as an ornamental. The seed is a small, dark nutlet, produced in quantity, and the plant self-sows readily in a gravel garden or a meadow.
Its native range covers the northern prairies and dry open woodland of central North America, from Manitoba to Colorado, on well-drained, often sandy or rocky soils. It is a plant of full sun and sharp drainage, and it rots in wet, heavy ground in winter.
Science & Biotechnology
The scent is a mixture of phenylpropanoids, and the main component is estragole, also called methyl chavicol, which is the same compound that gives basil and tarragon their anise note. Estragole is the subject of a regulatory caution: high doses have caused liver tumours in rodent studies, and the European Union restricts its use in food, which is why anise hyssop oil is not approved as a food additive in the same way as some other herbs. A cup of tea made from a few leaves is a different matter from a concentrated essential oil, but the distinction is worth knowing.
The plant is a classic pollinator magnet, and the reason is the flower structure. The tubular flowers hold nectar at the base, accessible to long-tongued bees and to butterflies but not to short-tongued flies, and the long flowering period from July to October means the plant is still producing nectar when most prairie species have finished. In pollinator trials it consistently ranks among the top plants for bee visitation.
The genus Agastache contains about twenty species, all North American except a few Asian ones, and it has been divided into sections based on flower colour and leaf chemistry. Anise hyssop is in the section with blue flowers and estragole-rich leaves, and it hybridises readily with related species, which is why the nursery trade offers a confusing range of named forms.
The seed is small and light, and it is dispersed by wind and by water over short distances. It requires light to germinate and should not be buried when sown. In the wild it colonises disturbed ground and prairie edges, and it is an early successional species rather than a climax one.
Uses & Benefits
The leaves are the main culinary and medicinal part. Fresh or dried, they make a pleasant, mildly sweet tea with an anise flavour, and they are used to flavour drinks, fruit salads and desserts. The flowers are edible and are used as a garnish, and they have a sweeter, milder taste than the leaves. The plant is one of the standard ingredients of the herbal tea tradition of North America.
In the garden it is a first-rate pollinator plant, and it is also a good cut flower, with a long vase life and a scent that carries indoors. It combines well with grasses, with echinacea and with the other prairie perennials, and it holds its shape without staking in full sun. It is a good plant for a herb garden, a meadow or a border, and it is tolerant of drought once established.
The medicinal use is gentle and mainly traditional. Anise hyssop tea is used for digestive complaints, for coughs and colds, and as a mild sedative in Native American and settler practice, and the leaves have been used externally for skin complaints. Modern research has looked at the antimicrobial activity of the essential oil, but the evidence is preliminary and the estragole caution limits how much oil should be consumed.
Ecologically the plant is one of the best nectar sources for bees in late summer and autumn, and it is also a host for the larvae of several moths. In a garden managed for pollinators, it is close to essential, and it is one of the few plants that will flower prolifically in its first year from seed.
Growing from Seed
Sow the seed on the surface of a loose, free-draining mix in spring, and do not cover it, since light is required for germination. Press it gently into the surface, keep the mix moist but not wet, and hold at eighteen to twenty-two degrees. Germination is usually two to three weeks, and the seedlings are small and slow at first.
Grow the seedlings on in full sun, in a gritty mix, and plant out once the root has filled the pot, into a well-drained soil. Do not enrich the ground, since rich soil produces soft growth and fewer flowers. Water through the first summer, then only in severe drought. Cut the plants back by half in early summer to encourage a bushier habit and a later, longer flowering period, and leave the seed heads standing for the birds in winter.
Our Take
Anise hyssop is one of those rare plants that is genuinely useful in three different ways: it makes a good tea, it feeds every bee in the neighbourhood, and it looks good for four months. It is easy from seed, it flowers in the first year, and it asks only for sun and drainage. Plant it once, and you will have it for good.
Related Reading
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