Commonly called 'garlic rust' it starts on the plant foliage and spreads rapidly from leaves touching and through spores being blown from plant to plant by wind - so it can take over a whole crop very quickly. But some alliums seem to be more prone to it than others.

For example when our own garlic suffered badly with rust it spread through our crop devastatingly quickly (big, sad, sigh), but the clumping onions in the next row seemed unaffected.

Excess moisture, both in the air and soil, plus over crowding plants are the most common causes of rust.

In our own garden I initially noticed a slight discolouration on the garlic leaves in only one section of the patch, so I made a point to check on it closely 'later'.

However, it was two days before I got back there and by that time the rust was well advanced, but just in that one area.

This is the region in our garden I refer to as the 'mud pit' - when the excavator created the terraces, the driver got more subsoil on top than actual topsoil unfortunately.

This resulted in really heavy, sticky clay in that particular spot... and this is where the garlic rust crept in.

Yup, it always comes back to the soil.

Apparently garlic rust can kill your whole crop if you just let it go. The rust reduces the vigor of each plant it affects, meaning your garlic bulbs will be drastically smaller compared to healthy plants.

One remedy for garlic rust is to prune the affected leaves from the plants. This can reduce rust spreading, meaning you'll still get some kind of yield from the crop. When giving my garlic a 'pretty full-on haircut' didn't work, I turned to the Australian Garlic Industry Association for help. They have a fact sheet listing a number of ways to treat rust with fungicides, including with copper oxychloride (250g per 100L of water) and lime sulphur (1L per 100 L of water).

We gave our crop one spray using copper oxychloride (which we also use to prevent leaf curl on our nectarine tree) and were impressed and relieved with how it slowed the spread and impact of the rust on our crop. We'll still need to harvest it a tad early, but it's helped significantly. (You can find complete instructions on using the fungicides at garlicaustralia.asn.au).

Watering: Don't water your garlic in the evening/night as this moisture will linger overnight and allow the perfect environment for fungus to creep in. Water in the morning so the plants can dry out throughout the day. You can also consider installing drip line irrigation to avoid all overhead watering. (Of course if it rains in the evening there's not much you can do).

Soil: If you have heavy clay soils, you can do things like add sand (works on a smaller scale), compost, ramial woodchips and plant your garlic in mounds. However we did most of these things and still got it, so choose another area of your garden with better soil if you have it or consider container gardening for this one crop. Like I said, our clumping onions are doing fine in the same location, it seems the garlic is particularly sensitive.

Tools: When dealing with any type of plant disease it's important to sterilise your tools/materials that came into contact with. Make sure you wash your hands before working in other areas of the garden and change/wash your clothes as well.

Crop rotation: To prevent lots of different soil diseases, rotate your vegetable families each season. Leave it about seven years before planting garlic in the infected garden bed. Luckily we have other spaces so it's not a death sentence for alliums in our garden... hopefully.

Wish us luck!