Ginseng is a herbaceous perennial plant native to the deciduous forests of North America and Asia. Ginseng has been used as a traditional medicine in Asian and Native American cultures for many centuries. Asian ginseng and American ginseng are considered to have the best medicinal properties and are therefore the most important from an economic perspective.
Ginseng use can be traced back in China for over 4000 years. One emperor named it the most potent herb known to man. It is known as a tonic and prevents conditions such as poor blood circulation, slow metabolism, poor digestion and a lack of vitality.
Ginseng use in the world today is based around two species. Asian ginseng (Panax ginseng) found in parts of Asia; and American ginseng (Panax quinquefolium) found in North America. Another medicinal product named Siberian ginseng is also available, but this is from a completely different plant. It does not have the active ingredients ginsenoside and panaxocide, that make true ginsengs useful in herbal medicine.
Ginseng can be grown a number of ways, each resulting in roots that can be sold. The only common factor is the need for shade from the sun. This plant grows naturally on the forest floor and does not tolerate bright sunlight – it seems to grow best in a light level of only 15–20 percent of normal.
Ginseng is used widely today in herbal, health food and cosmetic applications. Ginseng tonic is believed to enhance vitality, increase stamina, and help build up resistance to stress and disease.
Wild-harvested root is the most valuable of the ginseng roots, followed by roots grown in a natural forest environment, or wild-simulated ginseng, such as those grown in New Zealand. The third and most common method is growing ginseng under artificial shade structures, which results in the lowest-priced root.
Ginseng root prices vary depending on the quality of the harvested root, but for high-quality root, prices range between $1,000–2,000/kg.
Ginseng is used in health supplements using extracts of the active ingredients ginsenoside and panaxocide. Health supplements can be manufactured in New Zealand.
In New Zealand, wild-simulated ginseng is grown under a forest canopy, once pruning and thinning activities have been completed to allow for uninterrupted non-disturbance of the forest floor. If the forest area is divided up so a new crop area is planted each year, this allows for annual returns in successive years, following the initial crop in year seven, helping cashflow.
The following growing process has been developed by Maraeroa C, one of the larger growers of ginseng in New Zealand, who can advise on many of the details. For successful results, it is recommended to have a ginseng adviser oversee the growing and harvesting process, especially if on a large scale, to ensure the crop is well tended and the value of the crop can be maximised.
- Seed procurement and stratification or seedling procurement: Ginseng can be grown from seeds or seedlings. Seed can be planted at 15 kg of seed per hectare. Seeds need to be stratified before planting, i.e. a process of exposing seeds to a cycle of seasons over a 12-month period to improve germination rates. Seedlings can be purchased at one year or two years old, which reduces growing time by that amount. Planting seedlings may result in a greater yield because of a greater area utilised and a potentially greater survival rate. Approximately 100,000–130,000 seedlings can be planted per hectare, depending on conditions.
- Site selection – light and soil: Most commercial production of ginseng occurs in areas that experience a continental-type climate, with cold winters and dry summers. Simulated wild ginseng grows best under a forest canopy with around 80 percent shade. Light conditions for a site can be calculated by a research organisation such as SCION. A soil test will be required to test suitability, however a sandy loam is preferable. This ensures the roots are not always wet (wet roots can lead to a range of different fungal and bacterial diseases), and it allows the roots to be easily harvested without damaging them. The optimum pH level is 5.5, so soils low in pH will require lime. Lime should be applied during the clearing stages and ideally before the soil is cultivated. A gentle slope will help facilitate the shedding of surface water. If irrigation is required during dry periods, a T-tape or drip system on the soil surface is thought to be the best.
- Site preparation: The site needs to be cleared of all weeds 12 months in advance, firstly sprayed in late summer/early autumn with a glyphosate-based chemical to kill weeds, and then after the weeds have died back, the site should be cleared to remove debris, tree thinnings and obstacles, with minimal soil and tree disturbance. The site will require at least one further cultivation/harrowing and one further spray before planting.
- Fencing: Site fencing is required to protect the plantation from predation by hares, rabbits and other browsing mammals. This entails the use of fencing and steel mesh sufficient to keep predators out. While a square layout requires less fencing, if planted in a pine tree layout, the plantation site would likely be long and thin, necessitating more fencing.
- Establishment: After planting seeds, nets need to be erected to protect from bird predation for the first two years. This can be achieved by suspending bird netting over the beds using steel posts and wire as the support structure. Following this period, the nets can be recycled onto other plantations. If planting seedlings, bird netting is not required, as the plants have passed the vulnerable stage.
- Monitoring and maintenance: Maintenance in the first season following planting is most important. Slugs and snail have the potential to cause extreme damage to plantations (though this may not be a problem in all sites and years), so slug bait may be necessary. Weeds may not be an issue due to the low-light conditions, however control of weeds in the plantation is important, either manually or through a spray programme. The periodic clearing of tree debris, including branches and windfall, will be required.
- Pest and disease management: Ginseng can be affected by fungal pathogens and other pests that affect horticultural crops. If properly established, there is reduced likelihood of pest and disease issues, though monitoring is important to keep any issues in check. The wild-simulated growing method involves minimal chemical inputs to ensure a residual-free and high-value end product. Therefore inorganic fungicides and pesticides should be used sparingly if necessary, and usage monitored.
- Harvesting: Wild-simulated ginseng root is harvested by hand, during late summer/autumn, when the ginseng plants have begun to go dormant (senesce). Harvesting correctly is a specialist task requiring the utmost care to meet the quality expectations of discerning buyers. Harvesting is by hand with simple gardening tools. Mechanical harvesting is not advisable due to the chance of damage to the ginseng root.
- Processing: Processing involves washing, grading, drying and packaging, and can be undertaken at one or several locations, depending on the location of a suitable factory. Care must be taken with washing to ensure the roots aren’t damaged. Basic grading can be undertaken by packhouse staff, but further grading would need to be done by an industry professional. Low-grade ginseng would go into powder, medium-grade packaged in bulk for export, and high-grade individually packaged for sale.
Infrastructure demands for ginseng aren’t great, depending on the amount of post-harvest processing undertaken by the landowner or contractors. Some requirements are:
- predator-proof fencing around each site/block;
- netting structures erected over seeds for first two years;
- a packhouse/warehouse for washing, grading and drying, unless shared facilities can be accessed or a partnership with processing facility;
- seed drill if planting seeds;
- bobcat or similar for clearing work.
Most environmental issues have been identified above within the growing process.
No research is available for nitrogen leaching of ginseng, however it is considered to be in the low range. Any land use change to ginseng planned for the Lake Rotorua catchment would need to be modelled for nitrogen leaching.
Establishment costs for a ginseng plantation is estimated to be between $30,000 and $40,000 per hectare for planting seeds. The establishment costs for planting 100,000 x 2-year seedlings is approximately $120,000 due to the seedling cost (est. $0.70) and the extra labour costs for planting.
The value of the return depends entirely on the quality of the ginseng root harvested and the amount harvested per hectare.
With 45,000 roots harvested per hectare, this roughly equates to 675 kg @ $1,000–2,000 per kg for premium quality ginseng.
Therefore, for seven-year-old roots that have no chemical residues and are high in ginsensoside, one hectare could provide a gross return of $675,000–1,300,000 in seven years.
Maraeroa C Incorporation
Glen Katu, Chief Executive
PO Box 376, Te Kuiti 3910
T: 07 878 7177
Maraeroa C Ginseng Resource Requirement Assessment, Ministry of Primary Industries 2013 (http://maxa.mpi.govt.nz/sff/about-projects/search/M12-153/m12-153-ginseng-resource-requirement-assessment.pdf)
Alternative Crops Suitable for the Tararua District: Stage 2 Report 2006, Tararua District Council (http://www.tararuadc.govt.nz/files/cbb812d9-ba1f-419a-982d-a1e9010f0cad/alternative_suitable_crops_for_the_tararua_%20district_-_stage_2_report.pdf)
Ginseng (Panax spp.), Venture Southland 2013 (http://www.venturesouthland.co.nz/Economic-Development/Regional-Projects/Agriculture-and-Food/articleType/ArticleView/articleId/245/categoryId/205/Ginseng-Panax-spp)