Managing Pear/ Apple Scab (and other fruit tree fungi)

Pear ScabA mild winter followed by a wet spring means only one thing – Fungus. And this spring the fungi are having a party in my Winter Nellis (in the form of pear scab). To tell you the truth, I take it personally. How dare he get scab after all that lovin’? How dare he!! There is no airflow problem here – he is, of course, pruned beautifully; comfrey, seaweed and Rokdust worship at his feet; as well as all the required dormant sprays plus monthly seaweed foliar feeds. What more can a poor girl do?

Nothing, on reflection. There is nothing more I could have done. Sometimes the weather causes a ruckus, and it’s as simple as that. A variety of varieties solves this issue, each variety suited to a particular weather condition, and some (bless ’em) keep in top nick with whatever weather comes along. My goal is to thin out all the troubled souls leaving behind the bomb proof and low maintenance. Sometimes I don’t know whether I’m lazy or smart, but as you’ll soon read – managing fungus is very time-consuming.

A bit about fungi

Fungi are fascinating and are either soil-borne or airborne, incredibly beneficial or incredibly damaging. Beneficial soil fungi are essential to the overall health of our gardens, working symbiotically with plants in a harmonious nutrient interchange. To this end we should consider carefully before using fungicides, and it’s the reason I don’t recommend using them regularly, in that willy nilly no thought kind of way that sticking to a spraying calendar creates. Just because it’s August doesn’t mean you HAVE to lime sulfur – the thing is do you need to?

An ounce of prevention is worth a pound of cure

Prevention means good airflow, right plant in the right place, diversity of crops, best watering practice and good nutrition. In the right conditions airborne fungi will invade the living tissue of a plant/ tree and greatly weaken it by robbing all the nutrients. Scab, leaf curl, black spot, blight, rust, mildew, rot are but a few of these insidious fungi. Do nothing, and the disease will set up a cycle to continue year after year.

Dare to be disease-prone in my garden and you’re likely to end up as fuel for the oven. I’m not so merciless that I won’t put my best foot forward; you know, put a bit of effort in.  I’ll give it a few years to see if I can turn Mr Nellis around.

Slowing the fungi down

Here are some ideas of what to do:

Were the infection minor – just a few spots here and there, I’d dose fortnightly with baking soda or milk sprays to slow the spread. My scab has gone too far for this and on the next available dry day I’ll trim out the infected twigs, followed with a copper spray which I’ll repeat in 14 days. Copper should always be sprayed in the morning so the leaves can dry out quickly. That I’ll be spraying with seaweed monthly to increase resistance goes without saying.

Gathering as many infected fallen bits as possible moderates next years infection. This is like outside housework, it’s back to basics hygiene and is an important part of organic disease management. It’s the bit where I get an ‘f for fail’  … oh for the time! The fungi continue to flourish in the leaves on the ground and get splashed back up with rain or sprinklers. More likely I’ll opt instead to pile up some mulch which prevents some splash back.

Come autumn, I’ll copper spray at leaf fall, lime sulfur when dormant and copper again at bud burst in spring.

The truth is the scab is in. Anything I do now is with my eyes on next year. My efforts combined with dry weather would minimise the damage. The future, however, doesn’t look so bright – should a miracle on earth occur and the MetService be correct, the rain looks likely to continue in which case the fungus will party on.


  1. Hi Kath,
    Liked reading your blog about the fungi. I feel very much the same about it with my orchard.
    I can’t get rid of the b. leaf curl. A bit frustrating as I did all the right things and it is still there. One way of looking at it is that it would have been worse if i didn’t do anything.


    • Hi Uzi

      You’re right – it would be worse! Sometimes a fruit tree can still bear nice fruit while living with a repeat infection and sometimes it doesn’t. In the case of the latter you can always (bravely) chop it out and replace it with a resistant variety.

      kind regards