“How magnificent it sounds! That is the fun of writing of one’s garden: a steep bank can be a cliff, a puddle a pool, a pool a lake, bog and moraine sound as though a guide were needed to find your way across them, and yet may be covered by a sheet of the Times. My Dolomites like within the compass of my outstretched arms.”
Edward Augustus Bowles My Garden in Spring (1914)
This is not a happy tree and that is not autumn colour you are looking at. It is a slow death spiral unless we can intervene. Despite sharing the same reservations as most New Zealanders about variegated yellow conifers, we regard this one as special and wish to keep it. It is Chamaecyparis obutusa lutea nana and after about 40 years, it is a handsome, small feature tree in our rockery, not much over two metres tall.
The spiral-type pattern of the dead sections is a sign that it is a root problem and that, so far, only the part of the root system that affects those sections of the canopy is failing. If one solid section of the tree was affected, it can indicate that the tree is dying from top down and that it may be possible to cut out the infected area. But the overall patchiness shows it is dying from bottom up.
While we are increasingly reluctant to reach for the chemical arsenal, the first step here is to saturate spray for phytophthora, a varied pathogen that attacks root systems. It is a problem in vineyards and a form of it caused the potato famines in Ireland. If that fails, the last ditch attempt will be with Trichodowel – fine pieces of dowelling, each impregnated, according to the packet with “not less than 100 million Trichoderma viride spores” (who counted?). The dowels are designed to be inserted into the trunk or branch where the good spore can multiply and maybe defeat the baddies. If it was a silver blight problem, we would use these first but it is either/or because the anti-fungal spray will kill the beneficial fungi.
If it wasn’t a valued feature plant, we would let nature take its course and we would not replace it with another woody plant which may suffer the same fate.
First published in the Waikato Times and reprinted here with their permission.