Genetics,  Environment and Tree Health

Over the years we have come to understand that tree health is just like our  health, is just like our chicken’s health etc. Health is determined by genetic strength, and environment.

That means we need to plant heritage fruit trees.

Heritage trees are the only trees we have that were selected and grown to be strong and healthy and high brix in the natural alive world without chemical industrial inputs… they have the best genetic strength, so long as we are careful about the selection process.

On top of that we must supply them with the minerals they need as well as the right amounts of air in the soil (50% ideally) and also the correct amount of soil moisture to avoid root stress and to enable the trees to pick up the minerals at all.

If we don’t do any one of these things pests or disease issues will undoubtedly result at some point in some form… they are all around  us all the time, waiting for a weak tree or body to invade

Our  suggestions to  ensure you have optimal tree health

  1. Buy a heritage fruit tree from growers practicing regenerative nursery production

  2. Buy trees grown in open ground that have a mark on them so you can replant in the same direction that have grown and need to be again to achieve optimal health

  3. Follow our suggested tree planting guide on the website. The air, the minerals, and the moisture are all critical.

  4. Only plant what you can take care of well. One tree well taken care of will produce more fruit than 10 trees that do not get their needs met.

  5. If you didn’t do that, get advice as to the best way to achieve a similar result. It may mean you have to feed your trees well each year with EF Soil Force or EF Nature’s Garden, get a Reams soil test etc.

  6. Mulch all trees with ramial wood chips from willow or poplar to encourage healthy fungi and nutrient cycling

  7. Find a way to water over summer if necessary

  8. Foliar feed/ and spray with Compost Tea and or Koanga Balance  in the short term.

  9. Take radical action in the short term while above gets happening  as below

Every year we have people emailing us with pictures of either pests or diseases on their fruit trees and asking us what the problem is and what they can do about it… there is loads of info on the internet to help you identify these problems ..If you have done the above or are in the process and need short term radical, fast acting  solutions then this is what we would do for the most common problems are:


Pear Slug (Caliroa selaci)

Pear slug is noticed on leaves in November / December as everything warms up and the pupae comes out of its case in the soil to lay eggs on the host tree. It  looks as though a slimy  black flattish slug is eating layers off the leaves, leaving just the lacy veins.

Solution :

Ensure your heritage trees are well mulched and watered and not living in a place with long grass and mineral deficient soil, as above.

Even when damage is bad can be stopped by deep watering of the tree and weekly foliar feeding and spraying with Koanga Balance (totally made up of microbes and fungi that keep things in a healthy balance)


Silver Leaf (Chondrostereum purpureum)

This is a fungal disease which often appears on the first flush of growth in Spring, (silvering of the leaves), disappears again until late autumn and then appears again.  Note that many ornamentals that carry it show no silvering of the leaves.

Silvery, often stunted  leaves can be seen on either a whole tree or parts of a branch or tree. Positive identification of infection is seen by cutting an infected branch greater than 3 cm and there will be brown dark wood in the centre of the branch. Try cutting that branch off 15cm past the brown infected centre and burning the wood   Silver leaf is transferred through the soil, and is extremely contagious.

Solution: With Silver leaf we would do the radical option first whilst taking care of the rest.

I have had several serious brushes with Silverleaf over the years bringing old unknown plant material into the Koanga nursery. I have successfully gotten rid of the silverleaf outbreaks  several times… This is what we do immediately we see the outbreak….

  1. Act fast, as soon as you see silver leaves

  2. Cut off any diseased branches back until there is no browning in the centre of the branch

  3. Either drill a hole in the tree trunk on the main trunk below all branches and insert a tricho dowel, or alternatively scrape approx 6sq cm of bark off the cambium layer and apply tricho paste on that area, then cover from the sunlight. We make tricho paste by mixing milk kefir  with Koanga Tricho Powder. This must be done when the sap is flowing freely up the trunk. This can also be done an an inoculant to prevent silver leaf. The cambium layer, the sap carries the tricho fungi throughout the tree, deactivating the silver leaf fungi.

  4. Ensure we are also following solutions 1-9 above. Healthy strong trees are far less likely to get sick


Bronze Beetle aka Tutai Ruru !!!

Bronze beetles damage (holes in leaves eaten at night most often but also in the day time).

These are the adult form of native NZ grass grubs. The juvenile form are grubs that eat the roots of grass underground, and then  which live and hatch and eat tree leaves particularly in times of water stress mostly in November/December.


A plant experiencing water stress is a beacon for these flying beetles. Soak the ground under your trees and mulch them. Ensure you have done a good job of designing your forest garden/orchard so that there is not just long grass in demineralised soil around the heavy feeding fruit trees… follow 1-9 everything above


Cicada damage

Zip like marks on the bark of main stems and branches that are actually the places cicadas lay their eggs. These hatch into larvae which eat the cambium layer of tree, and weaken the tree in that place. The worse the stress, the worse the damage.


Ensure before you plant trees that you are able to maintain moisture levels and avoid water stress. Once you have the damage it needs to be pruned out so you don’t get broken branches or even main trunks


Bacterial Blast (Pseudomonas syringae)

Sometimes called gummosis or bacterial canker looks like  lesions on the trunks and branches of stone fruit where gooey sap oozes, and often dieback on the growing tips and smaller branches. The oozing gummy sap smells sweet like golden syrup, This bacteria enters the trees during flowering and bud burst when the trees are stressed and especially when we have a cool wet Spring.


  1. Ensuring 1-9 above are taken care of  is critical, and is the long term solution . Moist but well drained soil is super critical, I have noticed that trees in poorly drained areas always get this worst.

  2. Weekly foliar sprays during flowering and bud burst alternating a nourishing foliar eg EF:FruitFoliar with Compost tea or KoangaBalance will help to prevent infection and keep it to a low level where it is no problem


Leaf Curl

Bubbly reddish colour leaves usually occurring on the first flush of growth in spring, most often disappearing with second flush, usually mild but occasionally serious.


  1. Ensure you have got a heritage tree grown in alive soil from a  regeneratively managed nursery .. selecting for healthy trees

  2. Ensure you do 1-9 above, and it will not be an issue that  needs attention


Die Back

Where the tips die back sometimes, with the tree not getting bigger in the first year or two after planting. Usually occurs because the tree was not pruned before planting, and it was not planted with enough care and/or not watered well enough, also water stress.


  1. Always prune your deciduous fruit trees back a minimum of ⅓ of the tree before planting

  2. Ensure  you use the planting instructions blow and maintain moist environment but not waterlogged!


Codlin Moth – ( Cydia pomonella)

As we are learning through the science of biological agriculture and epigenetics, our plants and animals and humans will only attract pests and diseases if they are out of balance and not resonating at their best functioning level. Pests and diseases are nature’s way of cleaning up the rubbish!! Apple trees get all kinds of diseases and pests and almost all of them are because the mineral levels in the ground are not optimal, and most are because of a lack of available calcium.


Put the focus on soil health and ecosystem health and over time as  ecosystem restoration kicks in your codlin moth will disappear.. that is the only regenerative appropriate to home gardeners  way I know of to deal with such problems, this is why forest garden support species are so so important, and in this case poultry under the trees as well as 1-9 above. Note that some pip fruit is way less susceptible than others. As we learn these cultivars we will publish this information