Star anise (illicium verum) is a tree related to the magnolia and its dried fruits are used in many international cuisines. Star anise plants can only be grown in United States Department of Agriculture zones 8 to 10, but for northern gardeners, it is still fun to learn about a unique and flavorful plant. There are many star anise uses too, both for scent and flavor. Read on to learn how to grow star anise in suitable areas and find out how to use this amazing spice.
I. Appearance and Characteristics
Illicium verum (star anise or badian, Chinese star anise, star anise seed, star aniseed and star of anise) is a medium-sized evergreen tree native to northeast Vietnam and South China.
Illicium comes from the Latin illicio meaning “entice” or “seduce”. Verum means “true” or “genuine”.
The name “badian” appears to derive, via French badiane, from the apparently descriptive Chinese name for it, 八角, pinyin: bājiǎo, lit. “eight horns”. However, a derivation from the Persian بادیان bādiyān, “fennel”, exists, with the Oxford English Dictionary indicating that its origin before that is unknown.
Leaves are aromatic, simple and lanceolate, obovate-elliptic or elliptic, size of 5–15 cm × 2–5 cm, coriaceous to thickly coriaceous. The leaves are 5–15 cm × 1.5–5 cm, apex acute, lower side pubescent. Flowers are solitary, bisexual, pink to dark red, axillary or subterminal. The perianth has lobes 7–12, arranged spirally; stamens number of 11–20, arranged spirally, with short, thick filaments; carpels usually 8, free, arranged in a single whorl. Flower peduncle size is 1.5–4 cm, tepals number range from seven to twelve, and are broadly elliptic to broadly ovate, anthers size is 1–1.5 mm, pollen grains trisyncolpate.
The fruit is a capsule-like follicetum, star-shaped, reddish-brown, consisting of six to eight follicles arranged in a whorl. Each follicle is boat-shaped, 1–2 cm long, rough and rigid, color reddish-brown, with 1 seed, opening along the ventral edge when ripe. carpels size of 10 mm long, boat-shaped; they are hard and wrinkled, containing one seed. Seeds are brown, compressed ovoid, smooth, shiny and brittle with approximate size of 8–9 mm × 6 mm.
Differences with similar taxa: Illicium anisatum had smaller fruits that does not form a regular star due to the abortion of some carpels. Also fruit follicles are not swollen in the middle and had a more pointed apex. Also usually had more than 8 follicles and the fruit has weaker odour. The seeds in Illicium anisatum are flat or almost spherical.
II. How to Grow and Care
Sunlight and Temperature
To grow a star anise plant outdoors, make sure it gets dappled shade in the afternoon. Full sun to partial shade in the morning is ok. In the wild, star anise lives in subtropical climates underneath the upper canopy. Plant it in a too sunny location, and find it doesn’t grow as well. Partial sun is a good rule of thumb here.
Star anise trees grow best in the southern United States in zones 7 through 9. They need hot summers and very mild winters to survive. They need extra protection in zones 7 and 8 where the temperature falls quickly in the winter. If the temperature falls suddenly, wrap your Chinese anise tree growing in the ground with a tree wrap. If it is in a container, take the container inside or put it in a greenhouse where temperatures are stable. In high heat, you won’t have any trouble. Just make sure to water as needed.
Watering and Humidity
Water the ground surrounding your star anise in the morning when the top 2 inches have dried out. This goes for containers and in-ground plantings. Keep the soil moist but not wet in between watering. When you grow star anise, give it at least 1 inch of water per week. Drip irrigation is one way to ensure water gets directly to the roots. In winter, do not water star anise as much as the soil won’t have the ability to dry out.
Soil
Growing star anise requires a rich, loamy soil type that is well-draining. To prepare your container or garden, add a generous amount of aged manure or well-rotted compost rich with nutrients. Make sure the soil texture is loose, and the pH is slightly acidic. Neutral soil is fine as well. Anywhere between a pH of 6.0 to 7.5 works well for growing star anise.
Fertilizing
The only fertilizer you need is more aged manure or compost rich with nutrients applied in spring. Simply add either or a mix of both to the ground surrounding your tree in a 1 to 2-inch layer. Then lightly water it in. Do not add this in winter or fall, as it will burn the tree.
Pruning
If you’d like to keep growing star anise as a shrub, you can prune the tips in winter. Take off no more than 6 inches per branch with sharp shears. Try not to use electrical tools which can make the branches and long leaves look hacked. Prune off weak branches as they appear. The same goes for any diseased branches. Overall, there are no special requirements for pruning star anise. The pods don’t need any special care because they are picked unripe. We’ll get to that later. Keep it nice and you’ll see why people plant these trees for their great decorative value.
Propagation
There are two ways to propagate and grow star anise from an existing plant. The first is by cuttings. Remove a 4-inch section of branch with a sharp knife, and plant it in a soil mix of perlite and sand or peat humus. Wait for it to root, and keep it healthy until next spring when it can be planted.
The second propagation method is by star anise seed. Once you’ve harvested and processed the pods, remove the seeds. Test them by placing them in water. Those that sink are viable. Then, plant them in a potting mix at a ½ inch depth. One per pot is best. Keep the soil moist and they’ll sprout in 4 to 8 weeks. The seeds that did not sink should be discarded.
Pests and Diseases
Common Pests
Grow star anise and find there are no pests to deal with! Pretty awesome, huh? This is why a star anise plant is a great plant to grow.
Common Diseases
Only two known diseases affect star anise (Illicium verum): Alternaria blight and downy mildew.
Alternaria blight generally affects star anise in China, but if you purchase from a nursery you might bring a diseased tree into your garden. The way the blight presents is first through a spot with a light ring on one or more leaves which eventually make the leaves collapse. Use applications of a copper fungicide spray once per week to treat blight.
Downy mildew affects star anise when conditions are too wet for too long. Water your tree from below to prevent this. Neem oil can be used as a preventative spray. Use copper fungicide at first identification of the problem. Remove any discolored leaves and branches which turn yellow as downy mildew progresses.
III. Uses and Benefits
- Medicinal uses
Star anise is the major source of the chemical compound shikimic acid, a primary precursor in the pharmaceutical synthesis of the antiinfluenza drug oseltamivir (Tamiflu). An industrial method for the production of shikimic acid using fermentation of E. coli bacteria was discovered in 2005, and applied in the 2009 swine flu pandemic to address Tamiflu shortages, eventually reversing price increases for star anise as a raw material of shikimic acid. As of 2018, fermentation of E. coli was the manufacturing process of choice to produce shikimic acid for synthesis of Tamiflu.
- Culinary uses
Star anise contains anethole, the same compound that gives anise, an unrelated plant, its flavor. Star anise has come into use in the West as a less expensive substitute for anise in baking, as well as in liquor production, most distinctively in the production of the liqueur Galliano. Star anise enhances the flavor of meat.
It is used as a spice in preparation of biryani and masala chai all over the Indian subcontinent. It is widely used in Chinese cuisine, and in Malay and Indonesian cuisines. It is widely grown for commercial use in China, India, and most other countries in Asia. Star anise is an ingredient of the traditional five-spice powder of Chinese cooking. It is also a major ingredient in the making of phở, a Vietnamese noodle soup.
It is also used in the French recipe of mulled wine, vin chaud (hot wine). If allowed to steep in coffee, it deepens and enriches the flavor. The pods can be used in this manner multiple times by the potful or cup, as the ease of extraction of the taste components increases with the permeation of hot water.
- Cosmetic uses
IV. Harvesting and Storage
- Harvesting
Once pods appear in their rounded shape, remove them with garden shears individually and sun-dry them. When they are properly sun-dried and ready they will have changed from their more rounded shape to aniseed stars. This is where they get their “eight horns” reputation: from their star-shaped pod. Aniseed stars also change from green to reddish-brown. The pods pop open, and the fruit is used to flavor dishes once they are mature enough. To test this, take out a seed and pinch it. If you don’t smell that distinctive black licorice scent, they’re aren’t ready yet. Repeat the test over the following days. If your nose detects the black licorice scent, it’s the time!
- Storing
The taste components of star anise are paramount to Chinese cooking. If you’ve ever tasted star anise you know what I mean. This Chinese spice is used to flavor dishes there, in many international cuisines, and Asian cuisines as a whole. And in winter, anise is a great addition to hot wine. So how do you store the seeds once they emerge from the pod? First off, regardless of the state you choose to store them, make sure you have airtight containers. If you’ve chosen to leave the seeds in the pod, you’ll have star anise for your Asian cuisines for up to two years. Grind the seeds, and use them in dishes, or for their pest repellent properties for up to one year. Note that seeds that don’t have their distinctive aroma anymore aren’t useful. Discard these.
