Well I did say that garlic growing had reached a whole new level of personal interest after the Allotment Association talk last Monday, and I wasn’t wrong. The book I ordered – all 450 pages of it – was definitely a good buy, and coupled with some information from the talk I’ve been doing a bit of online research to see what the state of play is for organic gardeners..
The first thing to say is that the Isle of Wight Garlic Farm is not an organic operation and makes no claim to being one. I certainly don’t want to mount any high horse about that; it sounds like a commercial decision based on the challenges of achieving a consistent crop, and we’re free to buy or not to buy their products. Two things that were said induced me to get online. In the QA session after the talk it was said that the farm uses Dithane to control fungal diseases like white rot. They also operate a seven year field rotation, so they’re obviously taking no chances. When he was asked what to do if you get white rot, the speaker said “buy another farm!” – I’ve got more on that later.
In fact they can’t use Dithane because it’s been banned in the EU, and they probably went over to Systhane until that was banned as well, and current regulations seem to say that there are no chemical fungicides available to gardeners for use on food plants. That’s not a worry for us because we wouldn’t have used them anyway, but we have to accept that our losses to disease will be much harder to reduce and will need a holistic approach to plant health coupled with some hard observation of soil, weather conditions and rotation.
The second thought provoking suggestion in the talk was to give the garlic a dose of sulphate of ammonia in February. Sulphate of ammonia is a chemical fertilizer, produced by reacting ammonia with sulphuric acid. It adds, I discovered, both nitrate and sulphur to the ground but there are all the usual downsides of producing sappy, insect friendly growth and so-on. It also uses 1% of the world’s total energy production in its manufacture. But alliums – onions, garlic etc – all need sulphur which is one of the molecular components of the garlic byproduct, allicin, which is so good for us. Normally there’s sufficient sulphur in the soil, but apparently – and here you must remember my knowledge of plant biology is limited – apparently waterlogging does severe damage to plant roots and restricts the uptake of essential minerals. The take home point for us is that when we inherited our allotment the soil was continually waterlogged in the winter, and despite adding tons of compost; digging drains and raising beds, it’s still on the wet side.
The sequence of plant problems is that weakened plants get diseases more quickly and more severely than healthy ones. For the third consecutive year our leeks have been a miserable failure while others on higher allotments have not been affected. So putting aside sulphate of ammonia what else could be available to us as organic gardeners? One suggestion is to spray with a solution of Epsom salts – magnesium sulphate. It’s apparently allowable, but I’m assuming it’s a manufactured chemical and I know it hasn’t been made from natural Epsom spring water in living memory so it feels pretty non-organic to me. Then I came across some research on seaweed fertilizer which pretty much fits the bill. We often use it as a foliar spray, but it wouldn’t have occurred to me to use it in February. Research suggests that it’s a very effective source of minerals including sulphur. Anecdotally I can say that a car load of bagged and wet seaweed certainly smells as if it’s got some sulphur about it! – and it it makes a brilliant soil conditioner too. So in February we’ll spray the young alliums with liquid seaweed extract and I’ll report back. Other than that, I think we need to carry on raising the beds further above the water table and digging in organic material and horticultural grit.
Back to the book, and it’s been a revelation. I need to get a bit of organic chemistry into my head, but garlic’s claim to be a superfood seems to be well supported by independent research. The last 100 pages of the book are a summary of research into the use of garlic in folk and complementary medicine and the use of alliums and their derived substances as attractants, antibiotics, herbicides, pesticides and repellents in the environment. There’s all sorts of peer reviewed research in there including some work on companion planting which I’ve yet to read properly because I get excited and start skim-reading – a very bad habit and the reason why I’m not referencing any of the ideas.
But allotmenteering is all about taking the abstract and making it concrete, and so this all boils down to creating the best conditions for our own garlic by growing it in large pots filled with a home made mixture of soil, compost, horticultural sand, a sprinkle of fish blood and bone (not vegan then), and some vermiculite and perlite. This year we’re comparing 2 rows of Early Purple Wight softneck, grown direct in the allotment soil, and 25 plants of Carcassonne Wight hardneck in pots. They’ll all get the same seaweed treatment and hopefully we’ll be able to figure out how much the waterlogging is contributing to our difficulties. In practice this means carrying many kilos of ingredients down the steep paths and mixing them up in the wheelbarrow, which is extremely hard work but massively cheaper than buying bags of potting mix – which sometimes rely on peat in any case. This way we’ve only ourselves to blame if we get the mixture wrong.
So, after a hard day, we consoled ourselves with roasted root vegetables (mostly off the allotment) and couscous; another vegan tryout that was well worth the effort, but notwithstanding the affection of American readers for all things pumpkin – especially on Thanksgiving Weekend – even after being anointed with miso and all manner of herbs it didn’t really taste of very much.
The garlic book is – “Garlic and other Alliums – the Lore and the Science” by Eric Block, Royal Society of Chemistry Press. 454 pages and I can’t put the price here because Madame occasionally reads this blog!