To Copper Spray, Or Not?

fungalCankers, oozing sap, fruit scab, fruit rot, leaf spots, leaf curl or mildew are all signs bacteria or fungus are ruling the roost in your orchard. Today, I want to look at two ways to manage these infections:

  1. short term remedies of copper and lime sulfur,
  2. long term holistic loveliness.

We don’t need to be purists here – the two can tag team. A robust system takes a good few years to build, so until you get there (garden Nirvana I call it), the fungicides are a useful tool.


Fungicides are powerful medicine. They’re very good at their job, but there is a trade-off. They are non-selective, meaning they wipe everything out – the bad and the good (think antibiotics).

If resilience and less intervention are what you’re after – then you’ll be wanting to build the beneficial bacteria, fungus, nematodes et all, to the point where there is little room for the bad guys. To the point where your good guy army is too strong for the pathogens to get a foothold. While you build and create this thriving environment, it’s a big call to make – to wipe everyone out, but sometimes that’s what we feel we need to do.

A kind of two steps forward, one step back moment. The thing is, severe fungal/ bacterial problems are tricky beasts to bring back to balance, so nip them in the bud – I say. Copper those oozy, scabby, spotty trees.

How To Use Copper

It’s so important to spray these big impact sprays in a timely manner.

  • Spray at leaf fall, then again at bud break, with a second spray a fortnight later
  • Spray for full coverage – in all the nooks and crannies
  • Spray on a dry, still day
  • Wear a mask and sunnies
  • Follow the dilution rates to the T
  • Don’t mix copper with any other spray

How To Use Lime Sulfur

  • Spray while trees are dormant (never on an apricot).
  • Wear old clothes, a mask and sunnies and be prepared for the rotten egg smell!
  • Spray on a dry, still day.
  • Follow the dilution rates to the T
  • Don’t mix lime sulfur with any other spray

A Pathogen Prevention Plan (Building A Strong System)

Prevention is possible. And it looks like this

Sound Nutrition

Give your trees access to the nutrients they need, when they need them – from bud movement through to fruiting. Do this with

  • Free draining soil. Super important! This is something you need to sort before your trees go in. Wet soils have no air and tree roots need air for nutrient exchange/ uptake.
  • Humus rich soil is another key, do this with an annual layer of compost beneath the mulch in autumn.
  • The addition of a full spectrum mineral fertiliser and gypsum in spring.
  • Mulch to retain moisture and prevent fungal splash back

the orchard is 3!

Strong cells and active soils make for robust plants that are better equipped to cope with any conditions.
Will it be dry? Will it be wet? Hot? Cold? Windy? these things we just don’t know and can do nothing about.
Will we be strong – this we can do, this we can count on.

Foliar Sprays

Biological sprays do your trees and the eco system around them the world of good. Spray for complete cover – bark and foliage, also the soil beneath – go nuts! You can mix the following sprays together in any combination for a lovely bio brew. A good back pack sprayer makes your spray go further and makes the job easy.

  • EM – beneficial organisms to out-manoeuvre and out-compete detrimental fungi and bacteria. These fellas will speed decomposition so that leaf litter and fruit mummies disappear by spring when they become potentially dangerous. They boost ‘good’ fungi for balanced nutrition.
  • Fish Oil – smothers pests, good all round nutrition including nitrogen, strengthens foliage
  • Neem – disrupts pests feeding/ mating abilities whilst safe for beneficials
  • Seaweed – for thicker cell wells, pest prevention, stronger roots, makes nutrients more available, improves soil

 Herbal Ley

  • Nitrogen fixers provide an ongoing nutrient exchange for free! It’s smart to use them. Grow clovers and or legumes on your orchard floor or nitrogen fixing shrubs/ trees throughout or on the border.
  • Deep rooting companions like comfrey, chicory and dandelion recycle nutrients, open clay and hold sand – they’re value is enormous. Comfrey beneath your trees saves you the job of mulching and brings a nutrient exchange like no other.
  • Plenty of herbs and flowers to discourage pests with scents, and to feed beneficial insects

comfrey in flower

Light And Air

  • Good light makes for productive wood.
  • Airflow prevents moulds and fungus and assists pollination.
  • Prune and space your trees well.


  • Clean your pruning tools after pruning each tree to prevent the spread of disease.
  • Burn diseased prunings
  • Feed diseased fruits to your pigs or chooks.

The Right Variety

Varieties that suit your climate and soil are an important strategy. Varieties that don’t match up will struggle and become pest and disease magnets. Ask at local nurseries, neighbours or the garden club. Golden Queen peaches, for instance, are for the Hawkes Bay. Not for me – too much spring rain = leaf curl.

Thoughtful pruning

Prune in dry weather only and don’t be too hard (or too soft) – just right 🙂



  1. Kara Wright says:

    Hi – Could you please tell me if I can use copper and lime sulphur sprays on citrus? I have what look like rust spots on my lemon trees at the moment. Thanks!

    • Good to check – most definately not lime sulfur! You can use copper – usually late autumn depending on what you’ve got going on. How about you send through a piccy.

  2. Hi Kath,
    Avo,s they seem to have quite yellow leaves?
    How best to make soil ph about 6.7
    cheers Carina