Growing truffles in New Zealand
Truffières have been planted from Whangarei to Southland
Site selection
Perigord black truffières thrive best on sites that with the following characteristics:
- free draining soils, preferably loamy soil with no more than 30 percent clay,
- at least 50 m (preferably 100 m) separation from any tree which may harbour competing ectomycorrhizal fungi
- a good sunny aspect with high sunshine hours, to create an open, sunny woodland
- a soil pH of 7.5 or higher
- around 700 mm of rainfall.
The first three characteristics are very site dependent. Soil pH and rainfall can be artificially amended though the addition of lime and installation of irrigation. The history of a site is also important. Sites with high concentrations of copper or phosphorus may be wholly unsuitable unless levels can be reduced.
Bianchetto (Tuber borchii) truffières require similar conditions, but are more tolerant of lower pH soils. Burgundy truffles (T aestivum) prefer shaded woodland conditions, and more moisture, as does Tuber brumale. All three will thrive in cooler conditions than the Perigord black.
Site preparation
Preparing a site for planting of truffle seedlings will include working the soil to remove any pans which may impede soil drainage and incorporate any lime or dolomite added to raise pH. For some sites, it may be worthwhile removing or breaking up larger stones as this can improve drainage and prevent deformations in truffle shape later on.
Planning your orchard
Before you order your truffle innoculated seedlings (please read our advice on verification of seedling quality), you will need to decide how to set out your truffière.
Typically, trees are planted in rows running north south to maximise the sun on the ground.
Planting densities vary depending on the truffle species, intended orchard management, and climate. Typically planting densities of around 400 trees per hectare are recommended for Perigord black truffles. However this may vary depending on the local climate, the type of tree planted (oaks are big trees and may do better with a reduced planting density), and the intending pruning regime (hard pruning trees to keep them below 3m may allow a higher density of trees). For Burgundy truffles, higher planting densities will encourage early canopy formation to create the shady conditions the truffle prefers.
If you are going to install irrigation, it’s easiest to do so before the trees are planted. A good idea is to ensure the irrigation design is such that the irrigation lines can be removed or lifted to allow soil cultivation around the trees each spring. Cultivation around the trees isn’t necessary until the trees are around five years old.