Prevent Fungal Disease: Now is your Moment!



By far and away the most common cause of garden disease is airborne fungi. The mild moist conditions of spring set the scene for primary infections of rust, black spot, leaf curl, shot hole, brown rot and other fungal delights.

As I write this it’s raining and cool, the kind of conditions that strike fear in a growers heart. I feel happiness filled knowing my spray of EM and nettle tea has leaf surfaces colonised with good guys, in a timely manner.

Prevention is smart, especially if your garden is prone – now is the moment.


  • Airflow is key. Create space around vulnerable plants like roses and peaches with good pruning and keep vegetables like celery and garlic weed free.
  • Raindrops flick spores from infected plant debris back up onto plants. Collecting up infected matter is a small task with big outcomes. Minimise the splash back effect with mulch.
  • Beneficial fungi brings balance. Colonise the surface of your plants and soil regularly with aerated compost tea, fermented herbal teas, good quality fermented liquid seaweed or EM.
  • There’s a two step benefit to spraying milk – calcium inhibits the growth of fungal spores and ferroglobulin protein in whey is toxic to fungus. Dilute 1:10 and spray weekly as a preventative where you usually have issues.
  • Rotate your crops

The Whole System

Drone shot of edible backyard nz

We are what we eat, and so too the garden. Too much rich stuff brings as many problems as not enough. It’s easy to get carried away with “more is better” but big doses of strong inputs make for strong reactions in our soils that grow lush, sweet vulnerable plants. Tread carefully with fresh manures, overdosing on anything no matter how natural and for best results stay away from artificial fertilisers.

Little and often is powerful. With a capital P. It’s steady and solid, like fresh picked leafy greens everyday, an evening glass of kvass or a daily stretch. Use gentle inputs like herbs, leaves, seaweed and compost – these are things that soil understands and quickly assimilates because together they’ve been at this business of soil building a very long time.

homegrown organic broccoli ediblebackyard nz

This kind of gardening grows plants that are a bit less lush but more fruitful with robust cells less susceptible to pest and disease and richer in nutrients. Better for the earth, better for us – we are winning all the way here.

choose the best soil in your garden

There is no silver bullet friends. It’s the coming together of many things, especially your own quiet observations and wonderings.

Fungicide: Pros and Cons

Once fungus gets a grip – it’s really hard to manage naturally. If it gets away on you, repeat sprays of sulfur will stay the infection. Without sending you into an anxious spin – be aware that sulfur sprays (copper too) are indiscriminate – beneficial fungi gets wiped as well. So for me – this is an emergency call. I have uprooted crops to stop the spread – tomatoes with verticulum wilt is one example, rather than use a fungicide. However I have in the past chosen to spray sulfur to save the day.