Nibbles: Seed travels, Carotenoids in cucumbers, Tea and hibiscus, Sea level rise, Tewolde on climate change, SPGRC

The salad in winter

It’s a common misconception that all plants that enjoy heat need heat to survive. Anastasia says as much when she “goes out on a limb” to suggest that spinach won’t survive at -40°F, and then conflates spinach in winter with tomatoes in winter. I’m going to abuse proprietorship to point out both that spinach is a cool-weather crop — despite what they do to it in California — and that it doesn’t need to be growing in order to be freshly available year round, although I concede that -40°F is probably pushing it somewhat. (Who would want a salad under those conditions anyway?)

Many plants, and spinach is a prime example, can survive freezing. They do so even better if they are primed by exposure to cold temperatures before the freeze hits, which is the natural way of things. If you sow spinach in late summer, and let it get to be a good size before hard winter arrives, it will survive reasonably well given minimal protection in the form of a cold frame or a polytunnel. And it will be ready to grow away again as soon as temperatures start to warm up again in the spring. Not just spinach either: the list is long.

This idea, of growing plants in the autumn and protecting them for harvest through the winter and an early start in spring, is nothing new. Victorian gardeners were past masters. In modern times it is most closely associated with the name of Eliot Coleman. As it happens, he prefers organic methods, but don’t let that put you off. His book is wonderfully practical and there’s a bit more background here.

And of course there’s more to leafy-greens-that-aren’t-lettuce than spinach, but surely I don’t need to belabour that point here. My conclusion is that while it takes planning and foresight, it is perfectly possible to have access to a local diverse diet in cold winters.

Home grown and heirlooms cause disaster

Organic tomato farmers in the northwest of the USA have been badly hit by late blight this year. New York Times Op-ed author Dan Barber blames heirloom varieties and the surge in home gardening.

Whether you thank Pollan or blame Wall Street, more than a third of American households is growing some of their own food this year, says the National Gardening Association. Home gardening has created a strong demand for tomato plants. And Walmart brings in truckloads of infected plantlets from the South, thus giving late blight an early start in unchecked terrain.

Barber suggests the use of education (plant pathology in the secondary school curriculum?) ((But Barber could learn a thing or two: he calls late blight a pathogen and a fungus. It is neither. It is a disease. Caused by Phytophthora infestans, which is an oomycete, an organism related to algae.)).

For all the new growers out there, what’s missing is not the inspiration, it’s the expertise, the agricultural wisdom and technical knowledge.

And those heirloom tomato varieties that farmers increasingly grow are highly susceptible to late blight. So why not use plant breeding?

It’s nostalgia when I celebrate heirloom tomatoes. These venerable tomato varieties are indeed important to preserve, and they’re often more flavorful than conventional varieties. But in our feverish pursuit of what’s old, we can marginalize the development of what could be new. (…) like the Mountain Magic tomato, an experimental variety from Cornell University that appears to be resistant.

And then there is diversity:

The other day I saw a farmer who was growing 30 or so different crops, with several varieties of the same vegetable. Some were heirloom varieties, many weren’t. He showed me where he had pulled out his late blight-infected tomato plants and replaced them with beans and an extra crop of Brussels sprouts for the fall. He won’t make the same profit as he would have from the tomato harvest, but he wasn’t complaining, either.

The observation that retailers and home gardeners, and heirloom varieties, may have caused a major shift in a crop disease is very interesting. But the evidence is rather anecdotal. Perhaps it was just the weather? I would like to know more. I am sure the plant pathologists at Cornell are working on it.

Dancing for agrobiodiversity

I’m reliably informed by my friend and colleague Ehsan Dulloo, who should know, that this Mauritian sega by Gilbert Narainsamy called “Plante Plante” is promoting homegarden planting and sharing agrobiodiversity with neighbours. Sounds good to me!