Introduction:

Anise myrtle tree’s natural distribution is found along streams and on lower slopes in the Nambucca and Bellinger Valleys.
Though not visibly different two dominant chemical varieties exist naturally.
Commercially available anise myrtle is the anise or liquorice flavoured variety with a high content (<90%) of trans-e-anethole with a low estragole and cis-anethole content.
Anise myrtle leaves are used as a flavouring ingredient in herbal teas, sauces, drinks, curry, cakes and other products. All commercially available anise myrtle comes from plantations in NSW.
In the past, most of the product that reached processors and restaurants (the main markets) was harvested from the wild. Market demand for consistent year-round supplies of the trans-e-anethole variety, combined with concerns over the environmental impact of wild harvesting in the often fragile and fragmented littoral rainforest and subtropical rainforest systems, means that cultivated plantings have replaced wild harvest.Anise myrtle performs well in the garden and has been an attractive ornamental tree in landscapes and home gardens for many years.

Climatic and soil requirements:

Anise myrtle grows naturally in a sub-tropical rainforest environment.
The tree prefers a nutrient rich soil of medium to heavy texture in a well-drained, sunny position. Young trees are particularly frost and drought tender and require irrigation during dry spells.
The trees prefer neutral instead of acid soils and are prone to yellowing in alkaline soils. Once established, the trees are relatively hardy and recover quickly from dry spells.

Plantation layout: Plantation layout needs to take several variables into account:

• Northerly aspects maximise sunlight and flat, free draining soils are preferred for mechanical harvesting.

• Ideally, orientation of rows should be north/south to provide equal amount of sunlight to all plants all-year round. This is not always possible due to property layout. A balance needs to be found between being able to effectively mow/slash and access between rows with machinery, minimise erosion and maximise sunlight.

• Cutting grown plants can be spaced at 2- 2.5m apart in single rows. Inter-row spacing depends on machinery used for maintenance or harvesting.

• Mono-cropping is advisable for mechanical harvest.

Wind protection: Wind protection for cutting grown anise myrtle is advised. Regular pruning will assist to prevent wind damage. Selected windbreaks or shelterbelts can lessen the impact of prevailing winds during the stormy season. Native windbreaks can add biodiversity values to the plantation area, reduce moisture requirements and provide habitat for insect predators; however the selection of native trees for the windbreak needs care as some trees may be allopathic to anise myrtle or increase disease potential.

Varieties: Two main varieties naturally exist.

A dominant estragole variety is regarded as unsuitable for commercial production.
Selected high trans-e-anethole varieties dominate plantation grown anise myrtle trees.
Most commercial specimens have been contract propagated.

Water requirements: At the moment there is only limited information available on the water requirements of anise myrtle.

The tree grows naturally in sub-tropical regions and is prone to suffer from drought, especially when young.

• Excessive irrigations, leading to extended periods of water logging, should be avoided.

• Cutting grown anise myrtle does not have a deep taproot and requires ample surface moisture and mulch to maintain leaf productivity in dry seasons.

• Extremely dry soil conditions should also be avoided.

• Within their range, plants normally experience a wet summer/autumn and dry winter/spring rainfall pattern.

Most importantly, growers should monitor and record their irrigations and soil moisture status using instruments such as tensiometers. This will help them and their advisors assess their current situation and practices, identify any problems and refine their future management.

Nutrition: The nutritional requirements for anise myrtle are not well documented, but the trees grow best in rich, fertile soils and need increasing amounts or organic fertilisers as they are maturing. The trees can be cut up to three times / year and as each harvest removes a large amount of biomass, it is essential to return nutrients for long-term productivity. As experience with the crop accumulates firmer guidelines and objective assessment techniques, such as leaf analyses will become available. Until then, some general principles should be kept in mind when designing a fertilizer program:

• Many Australian native plants are intolerant of high phosphorus levels, so a relatively low P fertilizer, suitable for natives, should probably be used.

• In the first season following establishment the aim should be to maximise growth to develop a good plant structure and produce several flushings.

• Once established, nutrient availability is necessary to promote excessive vegetative growth after harvesting.

• Documented regular observations, soil and corresponding leaf analyses will assist any grower to adjust their fertilizer regime.

Pest and diseases:
Anise myrtle has shown a remarkable resilience to pest and disease, however it can be affected by sooty moulds- especially if in close proximity to other native trees (shelterbelt) that foster it.

Canopy management: Plants need to be pruned regularly within the first years to provide a “shrubby” shape and to increase leaf production. Regular harvesting of leaf increases leaf production and keeps the tree from becoming woody.
Woody trees are best pruned heavily to increase subsequent yields.

Harvesting and Handling:
In Australia, anise myrtle leaves can be harvested all year round. Commercially available leaf products are typically cut from the tree and immediately after harvest placed into a drying unit. Some products are dried on stem, others are defoliated of the stem and various different methods are used within the industry to achieve a superior anise myrtle end product. The dried leaves are then processed (milled) to suit its application.

Yields: Yields will vary with variety, orchard fertility and management. Comprehensive data is not available at this present time.

Author: Sibylla Hess-Buschmann.
Contributors: Rus Glover.
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