Autumn Truffle Burns (Brulé)

Brulés in the Truffle Orchard
Brulés in the Truffle Orchard

This area was last mowed around a month ago. Autumn rain has greened the orchard, and the trees with active truffle colonies are quite visible.

  • Within the truffle burn (brulé -french for burnt) there is still some live grasses, but the burns are quite distinct compared to the inactive trees.  There no herbicides used in our truffle orchard at any time, the visible depletion of grass above is entirely due to the action of the truffle mycelium in the soil, where it lives on the tree’s roots.
  • There is a newly producing tree centre of the photograph and two more trees with truffles at 2 and 10 o’clock positions. There are also nice brule’s around the trees in the foreground, left and centre right.  As can be seen elsewhere in the photo, not all the trees have visible signs of truffle activity, and may never develop any.
  • Does a brulé mean there will be truffles? Simple answer, no, it’s just more likely to produce.  There are other competing fungi that can cause burns, and the truffle may not be ready to fruit this season, or lack some other requirement.  Active trees can also skip a few seasons before producing again, or become fully inactive.
Hazel tree needs maintenance
This Hazel tree has produced for the first time, and is in need of some maintenance.
  • Loose leaf litter is raked away from the brulé as it provides an environment for insects.
  • The hazel suckers are removed, sometimes leaving one and removing an angular branch. The primary goal of this is a tree shape which promotes soil warmth in Spring which start’s next season’s truffle activity.
  • Grass near the trunk is removed by careful cultivation, removing insect shelter.
  • There are also three near surface truffles on this tree (white tags), and a rotten one was removed.
  • This process took an hour, and there are 400 hazelnut trees in the truffle orchard, so priority is currently given to active trees. The rest will be done as time permits.
Hazel tree & Brule maintained
Hazel tree pruned, truffle burn cleared, surface truffles covered

Oak trees are easier to clear, but a little late for this as it one had a rotten truffle on the left side of the trunk, with insects sheltering in the grass likely culprits. The tree was double trunked several years ago, and was converted to a single with gradual pruning for minimal impact on growth.

Clearing Oak
Clearing Oak

Autumn, first signs of truffle

Although truffles first form in December, the first visible signs generally show in late February or Autumn.  These surface signs occur on the portion of the truffles that have either formed too close to the surface, or become so large a substantial amount of soil has been pushed toward the surface.

Surface_Truffle_Sign_114644
Truffle Push
Surface_Trufffle_Sign2_114753
Two truffles revealed

With access opened to the truffle via the cracks in the soil, these truffles are more susceptible to insect damage (Eg. slater & millipede in second pic above).  Regular searches for such signs, inspection and removal of rotten/damaged truffles, and covering the good ones is an important task at this time of year.  Rabbit’s that manage to get past the fencing are also attracted to the disturbed soil, and expose the truffles, sometimes learning to eat them too..

Along with other tasks, Autumn is now a full time job.  For every days work in harvest season, there’s around 5 days in supporting work such as this.