Growing Truffles

askrigg plantation picture

For many it is a dream to grow the mystical, rare and delicate fungi with the most arresting aroma in the culinary world.  And for those who have taken the plunge, once they find their first truffle, this dream easily becomes an obsession and a passion.

Growing truffles can be for simple personal pleasure or for profit, and plantations might contain a few trees or thousands. While the warm and enthusiastic words above may be inspiring, it must be emphasised that truffle growing is not a “get rich quick” project and should be viewed as a long term investment, which may or may not yield any returns (much the same as other agricultural pursuits).

The journey to grow truffles is not an easy one. There are over 160 commercial growers in Australia, but not all are producing truffles. Due to many variables some growers have invested substantial money and time into ventures that are only producing small quantities of truffle – while others are enjoying bountiful harvests and profits.  As a young industry our focus is on establishing proven R &D that growers can use and rely on, and this inevitably requires a group focus and requires group support. The membership of the Australia Truffle Growers Association is one such way the industry works to support and service commercial growers with new cultivational information as it comes available.

Having dedicated truffle growers with an attention to detail is the key to production. There has been a lot of collaboration between local and overseas truffle growers, marketers and research scientists over the past decades, both internationally and in Australia. The success that many growers are enjoying is in part due to these people, but also to the good old Aussie tradition of careful observation and being prepared to have a go at growing these fungi under conditions that some experts would doubt possible. There is now an array of management techniques available that have mitigated a lot of the growing problems, and members of Australian Truffle Growers Association are able to benefit from this collective knowledge.

Here are the basic requirements:

Climate

Truffle production requires hot summer temperatures and cold winter temperatures and climate is probably the primary issue. As a general rule, a mean daily temp of about 20 degrees in the January and mean daily of about 5 degrees in July is desirable. Some say a rule of thumb is at least 7 frosts during the winter but areas like Manjimup in West Australia get hardly any frost. See the excellent Diggers Club climate map for  that kind of information of your area. The areas we’ve mapped as suitable for truffle growing are the green zones shown on the map below. Of course there are regional differences and elevation to consider. And we haven’t considered the possible changes due to climate warming ten years ahead, when your trees would be producing.

Tree suppliers should already know of most of the climatic conditions in truffle growing regions, however it is suggested that you contact the Bureau of Meteorology and get the climate detail from a station of theirs close to you. Tree suppliers may need some climatic and soil information for your specific area before they are prepared to comment. The Comparative Climate Table of Europe, Australia and New Zealand will give you an idea of the range of climatic conditions in truffle producing areas. To date, truffles have been harvested in Australia at Manjimup in Western Australia, in Northern Tasmania, in the Yarra Valley, the Otways and parts of Gippsland in Victoria, the Australian Capital Territory and in the New South Wales Highlands from Jindabyne to Moss Vale and out to Oberon, Bathurst and Orange. The  member’s general locations can be seen by clicking on Members Location, but in many cases it is showing a contact address rather than truffiere location. Nevertheless it indicates the spread of the membership and nearby help offered to members who join the association.

Soil

Truffles generally grow in free draining poor quality soils – something we have a lot of in Australia. In addition to being free draining, soils also need to have a pH of 8, as well as other micro nutrient levels, which may need correcting, depending upon the results of the soil test. Most people are liming the soils to bring it up to the needed pH. For example soils of pH less than 6 might require 60 tonnes of lime per Ha to bring them up to a pH of 8. If you decide to go ahead, there are suppliers of  infected trees on our Recommended Trees page and they will be happy to assist you with advice on preparing your paddock.

Truffle production is currently coming from the south of Western Australia, many areas in NSW, the ACT, many parts of Victoria and of course, in Tasmania where the first truffle plantations were developed in the early 1990s. There are also plantations in South Australia and Queensland, however these plantations are not old enough to commence production yet. Truffles are also being produced in both islands of New Zealand.

Contact the State department responsible for soil conservation to get an idea of soil types in your local area and on your property; that would be a good start.

Irrigation/water

A minimum rainfall of at least 700 mm per year would be desirable and good rain in the summer months is required to set the truffles. You may need to drought proof your trees, particularly in the early stages, so you will need a good water supply, either surface or ground water, (but not saline). Truffles originated in forests growing on limestone soils and were not irrigated, so your area rainfall could influence your decision of whether to irrigate or not. Recent research has shown that both over watering and also no watering can both impact on truffle harvest quantities.

Innoculated trees

The Recommended Trees page includes suppliers of inoculated trees and they will be happy to assist you. Tree certification that has been initiated by the Association of Truffle Growers, to give growers a tool in managing risk of poorly inoculated trees. We recommend that you maximise your chance of production using certified trees.

Getting started

Before making any decisions about truffle cultivation, we recommend that you thoroughly look into the climate, soil and water resources on your property.  Thorough investigation and homework is vital, both so you understand your own property’s attributes and so you understand about the truffle, how and why it grows.  In addition to contacting your nearest Bureau of Meteorology station, you should also get a soil test done and talk to certified nurseries on our Recommended Trees page

Site preparation is straight forward by spraying out the grass, then adding lime and nutrients and chisel ploughing it in to the top 200 mm. Some recommend deep ripping with the Yoeman’s plough to improve the soil tilth and its water retention qualities. Another suggestion is that it is better to ensure thorough soils preparation well before planting, but it is best to discuss all these options and your particular situation with your tree supplier. You need to keep well away from existing trees as they may have competing mycorrhiza on their roots, which will compete with the truffle mycorrhiza. Again, check these issues with your tree supplier. Set out the tree lines, install tree guards and the irrigation (if required) and plant the trees, probably best in early spring. Some people plant in rows along the contours to better manage the soil moisture and reduce reliance on irrigation. The infected trees most commonly available are English oak, Holly oak and Hazelnut, but there are other suitable varieties; again check with your tree supplier. There are about 400 trees per ha (160 per acre) and don’t expect any change from, say, a ballpark $30,000/ha or $12,000/acre for the set-up, including fencing and irrigation. This price will come down to the degree you do work yourself – however costs will still be at least $15,000/ha even for the most industrious person.

Growers have been consistently getting truffles after 4 to 5 years with the new technology being employed, but earlier growers (in NZ and Tasmania) were waiting for 10 years or more before production commenced. It is, after all, an agricultural pursuit and comes with all those farm related issues. Harvesting is being done with the help of dogs and they are available for hire in most regions with some suppliers being able to either train a dog for you or assist with training practices.

Finally, growing truffles can be for simple personal pleasure or for profit and plantations might contain a few trees or thousands. While the warm and enthusiastic words above may be inspiring, it must be emphasised that truffle growing is not a “get rich quick” project and should be viewed as a long term investment, that may or may not yield any returns, much the same as other agricultural pursuits.