My garden and I share a dark secret – not one I'm proud of and, until yesterday, one from which I thought I could never escape. For the last 8 years, I've been cursed with club root. This unbelievably ghastly fungal disease affects brssicas and, as we all know, that means around 80 percent of all the vegetables in the garden – especially if you live in the south where gardeners rely on staples such as cabbage, cauliflower, broccoli, Asian greens, turnips, swedes, raddish, kale ... the list goes on.
You'll soon know if you have club root in your garden. The more susceptible brasicas such as broccoli, cabbage, and cauliflower are the first to succumb to this horrible disease, with more resistant cousins such as turnip, radish and swede soon following suit (hardy kale is the least likely in the brassica family to give in to club root. Club root causes the plant's roots to swell, twist, and contort, in much the same way a very arthritic hand might do so. The result is a tight, stunted knot of root, incapable of drawing up sufficient nutrient or moisture to sustain the plant or allow development. The first outward signs you may notice are a wilting in hot weather, stunted growth, a failure to "heart", or leaves turning a pinkish colour (as they do when nutrient-deprived).
Sadly, and this is where the news couldn't get any worse, there is no hope of recovery for the plant, and the fungus lingers in the soil for up to ten or more years, even when brassicas are withheld from the same bed. And, until now, I have been unaware of any organic method of prevention. Consequently, in the depths of my potting shed, I have for some years kept a container of Yates "Greenguard", a chemical treatment which, when mixed with water and used to drench the hole into which seedlings are being planted, keeps the dreaded club root at bay. Chemical fixes are the last thing I would ever reach for but, over the years, I've accepted the fact that if I don't grow my own brassicas, I must buy them from the supermarket (there being no organic vege shop within two hours of home), and there is no guarantee what they have been treated with!
So you can imagine my delight when a small-scale market gardening friend called in for a cuppa a week or two ago and told me that, for years, he has eradicated the deadly club root by a simple, if albeit labour-intensive, method. When he first encountered club root in his garden, he immediately organised his growing space into raised beds. Then, one bed at a time, over a period of years, he dug out the soil in each plot to a depth of around 15 cm. He then filled the beds with his own sterilised compost or, if he couldn't supply this himself, with compost purchased from a reliable commercial source. He was then able to plant and sow brassicas directly into the beds without their being affected by club root. So, while I imagined that the fungus would work its way through the soil, it seems that this is not so. I would give anything to biff that chemical fix-it solution into the bin, even the 2-3 hours it will take me to dig up one of my raised beds, and that's exactly what I'm going to do. I can cope with hard work, but I don't like watering chemicals onto my food. If only I'd heard of this organic solution years ago!
Tips for avoiding and managing club root
- Grow your own seedlings – club root often arrives in a garden with the purchase of commercial seedlings or the arrival of plants gifted from a friend.
- Lime your soil well – club root thrives in acid soils.
- Never compost the roots or stems of plants afflicted with club root.
- Rotate brassicas so that you are never planting them in the same garden bed two years in a row.
- Keep a set of garden tools specifically for working in non club root-infected garden beds to avoid spreading the disease into clean soil.
- While some organic gardeners swear by lining seedling hollows with torn rhubarb leaves at the time of transplanting, I have never found this helpful.
- Though you may not like the idea of chemical treatments, Yates' Greenguard is a quick fix for club root.