Emma the Gardener

A late start to day 18 of the April blog love challenge, but here are today’s blogs:

1. Dave Hamilton has been making Nettle Haggis.


2. Sowing seeds is ‘me time’ for At The Garden Gate.


3. The Double Life of Mrs M on the love of a decent high street.


4. Tom Moggach’s ideas for using Green shiso, herb of the gods, from last year.


5. In my Iraqi Kitchen’s recipe for watermelon jam.
   

Phew! Made it :)

Did you sleep well last night? You would not have felt so cosy if your mattress had been infested with bed bugs (Cimex lectularius), an ancient pest that is making a comeback in the modern world, complete with pesticide resistence. Looking for a new solution to this age-old problem, scientists from the Universities of California and Kentucky took their inspiration from reports written in the first half of the twentieth century (sadly not available online) that describe the use of bean leaves (in Eastern Europe) to trap bed bugs so that they can then be destroyed.

The reason that those reports are only now being taken seriously is that for more than 50 years, bed bugs haven’t been a problem for the majority of people living in the Western world. Since the Second World War, we have been dealing with infestations with pesticides, and we had been winning the bed bug war. But now they are appearing again in the US and the UK, and no one is entirely sure why the tide seems to be turning in their favour.

Bed bugs have plagued humanity since history began, and it’s thought that they evolved to parasitize bats before moving on to humans. When we were hunter-gatherers and roving herdsmen, we presented a moving target – there were no beds to house bugs. But it has been a different story since we started moving in to cities, and since we developed a taste for heating our homes in the winter that allows bed bugs to breed all year round.

And so intrepid researchers have been trying to find out exactly how bean leaves trap bed bugs, which involves collecting bean leaves, forcing bed bugs to wander over them and tracking how long it takes them to get stuck. Once they have got stuck, videography and scanning electron microscopy allows us to see exactly what they have got themselves stuck on.

And it turns out that the bean leaves are covered in hair-like sructures called trichomes that literally pierce the tarsi (essentially the foot) of the bed bugs, holding them fast. Sometimes the bugs aren’t pierced, but merely hooked, and on those occasions they can free themselves and carry on, but they don’t tend to get much further before being well and truly trapped.

The researchers went further and tried to create a new material with synthetic trichomes that would trap bed bugs, but they had limited success. Although they were able to accurately recreate the tips of the trichomes, they just didn’t have the piercing power of the real thing. They have attributed this to a mechanical effect in the natural trichome stalks that has yet to be replicated – more research is required.

By now I’m sure you’ve got some questions, so I’ll answer the ones I had when I read the paper.

What do bed bugs look like?
I’m glad you asked, because I had to look it up. They’re generally brown, with adults measuring up to 5 mm across and are “dorso-ventrally flattened” whatever that means. Google has pictures.

Which bean species traps bed bugs?
The researchers used Phaseolus vulgaris for their experiments. Here in the UK we call them French beans. Elsewhere theyr’e called common beans, green beans or kidney beans. There may be other bean species that would have the same effect.

Why do bean leaves trap bed bugs?
Well, that’s a good question. The paper points out that there is no evolutionary association between beans and bed bugs – bed bugs don’t eat plants, and so the plants would have no reason to evolve a defence against them. However, bed bugs are part of the Order Hemiptera, the true bugs, and most of those do eat plants. And so it seems reasonable to suggest that the bed bugs are falling foul of a defence mechanism aimed at a different bug, although since trichomes are microscopic we’re still learning about what they are and what functions they perform for the plant.

Why does the word trichome sound familiar?
You may have come across the word trichome because it is the trichomes on stinging nettles that are responsible for delivering the painful poison when you come into contact with the leaves. Alternatively, you may know the word because it is the trichomes on cannabis plants that produce the resins some people are fond of. I couldn’t possibly comment.

Why not use actual bean leaves to trap bed bugs?
We grow a lot of beans to eat, and they all have leaves, so why shouldn’t we use the leaves to trap bed bugs? There is no reason we can’t, of course, although you’d need a lot of leaves to control an infestation, and they have to be used fresh because the trichomes won’t be pointy enough on wilted leaves. But I imagine that most people these days would probably have a problem with bean leaves covering the carpet at night, not to mention having to take them out and stamp on the bugs every morning. If a synthetic version could be manufactured it could be incorporated into carpet, perhaps, or bed linen, and literally stop bed bugs in their tracks.

Were any bugs harmed during this experiment?
Yes, quite a few. Science can be brutal.

Is there, by chance, another fascinating fact to round off this story?
By Jove, I think there is. The herb Cilantro (Coriandrum sativum, known as Coriander in the UK) was probably named after the early Greek word for bed bug – Coris. The reason being that the scent released when you crush cilantro leaves and unripe fruits is reminiscent of bed bugs. Presumably only after they too, have been crushed. Something to look forward to, if you trap your own bed bugs and like the smell of Cilantro.

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If you are intrigued by this story, you can find out more about the experiment, and bed bugs in general, by reading the following:

Szyndler, M. W., Haynes, K. F., Potter, M. F., Corn, R. M., & Loudon, C. (2013). Entrapment of bed bugs by leaf trichomes inspires microfabrication of biomimetic surfaces. Journal of The Royal Society Interface, 10(83).

Potter, M. F. (2011). The History of Bed Bug Management – With Lessons from the Past. American Entomologist, 57(1), 15.

Boase, C. (2001). Bedbugs-back from the brink. Pesticide Outlook, 12(4), 159-162.

Welcome to day 17 of the April Blog Love Challenge :)

Today I have commented (or tried to!) on:

1. Rosalind Creasy’s Asian coleslaw from spring greens recipe.


2. Patchieri has been talking about roselles.


3. Jekka introduces us to lovely lumas, Chilean myrtles.


4. Edible Geography shows us that there more to roadkill than meets the eye, in Freeway Foraging.


5. And Ryan’s Garden is celebrating the arrival of the bumble bees.

See you tomorrow!

The beautiful Hyde Hall greenhouse (with cold frames) from the Gabriel Ash RHS greenhouse collection

Most vegetable gardeners lucky enough to have the use of a greenhouse use it for raising seeds early in the year, extending the season into the autumn, and of course growing tomatoes and cucumbers in the height of the summer. If you’d like to find something a little more exciting when you open the greenhouse door, these unusual crops will appreciate the extra heat.

Melons, Cucumis melo
Difficult to grow outside in the UK, melons enjoy the heat and humidity of the greenhouse. They are grown in the same way as cucumbers, trailing, or climbing up nets, and are best planted on a mound, as they don’t like getting their stems wet. You’ll need to prune them to encourage a good crop of fruit (start by pinching out the growing tip to make the plant bushy, then restrict the plant to four lateral stems and pinch out their growing tips when they have six leaves. Plants fruit on sub-laterals formed on these lateral stems). You’ll also need to feed your plants and keep them very well-watered once they start to flower and fruit.

You can also grow your own watermelons (Citrullus lanatus), for which seeds are sown indoors in April or May, although it’s best to choose an early variety that has been bred to crop well in the UK climate. You could be harvesting fruits weighing five kilos from midsummer, but they will need plenty of water! Like squash, watermelons have male and female flowers, and will benefit from a little help in the form of manual pollination. Prune in the same way as melons.

Peppers, Capsicum species.
It is perfectly possible to grow peppers (both sweet and chilli) outside in a sunny spot on the patio, or on a windowsill indoors. But they also make a great greenhouse crop, enjoying the extra light and heat. They’re treated in much the same way as tomatoes, and seeds have to be sown in late winter or early spring to get a head-start on the season, but you’ll still be able to buy plants at your local garden centre, and there’s a large range of varieties available mail order.

Peppers need to be given a high potash tomato feed every week once they start to flower and form fruits. And, like tomatoes, they need to be kept consistently damp to perform at their best. The ‘heat’ of a chilli depends on a number of factors, including the variety you choose and the weather – so in the event that we have a long, hot summer, handle with caution!

Most peppers grown in the UK are Capsicum annum species, but if you can take the heat and don’t mind a bit of hunting around you can often find seeds and plants for some of the less well-known species, including Rocotos (or Lotocos), which are C. pubescens and have lovely purple flowers.

Lab lab (or hyacinth) beans, Dolichos lablab or Lablab purpureus
Although relatively unknown in the UK, lab lab beans are an Asian favourite. They need protection to grow well in the UK, but if you have a polytunnel or a greenhouse then they can be grown in the same way as climbing French beans, with pods picked as soon as they are large enough to eat. As an added bonus, they have scented flowers that appear from July onwards from seeds sown in April.

Like French beans, lab lab beans are very varied – they come with different colours of both pods and flowers. Some are day length sensitive and will only crop well in the tropics, but there are also day neutral varieties that don’t mind our long summer days.

Dudi (also known as calabash, or the bottle gourd), Lagenaria sicceria
Dudi will grow outside in a good summer, but is more reliable in the greenhouse. It’s a popular Indian vegetable, a bit like a climbing courgette, and the fruits are best eaten when they are young. Like pumpkins, dudi seeds are sown in April or May and potted up into relatively rich soil. They make big plants, so give them plenty of space and a solid support to scramble up. If you do grow them, remember to pop out to the greenhouse in the evening so enjoy the flowers, which open at night!

Sweet potatoes, Ipomea batatas
Sweet potatoes have actually been grown in the UK for over 450 years, but they often don’t crop well outdoors in a British summer. Another big plant, they trail rather than climb, and need to be given a reasonable amount of space. They are grown from ‘slips’ which are cuttings taken from a seed potato, and sold in late spring. Slips need to be potted up and kept warm, before planting out into the greenhouse once they have established a good set of roots – plant them really deeply to encourage tuber production. They like the heat and humidity of the greenhouse and a rich soil, but don’t feed them too much nitrogen as that encourages leafy growth at the expense of the tubers.

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Melons and watermelons, all kinds of peppers, and sweet potatoes are all widely available from the major seed companies and garden centres. For anything more exotic try the Sowing New Seeds Project varieties available through the Heritage Seed Library, or a commercial supplier like Jungle Seeds.

Day 16 of the April Blog Love Challenge! Today’s commented blogs are:

1. Now that the sun has come out and spring is getting the hang of things, it’s good to have Hedvig’s recipe for nasturtium pesto to hand.


2. AncientFoods explains the theory that beer gave us civilization.


3. Modern farmer shows us how much plants like to be cradled.


4. Treehugger reports on the Indian villlage planting 111 trees every time a girl is born.


5. Root Simple is singing the praises of arugula flowers – that’s rocket to you and me :)

All done for today :D

The taught portion of my ethnobotany degree has come to an end, and this summer it’s time for me to undertake some research and then write it up for my dissertation. My project currently labours under the weighty title

“Co-production and transformation of knowledge regarding novel crops among digitally-literate homegardeners and allotmenteers in the UK”,

which is going to require some explanation.

I have tried to align my research with the topics I am most interested in, and so I am going to conduct it (for the most part) among the UK’s online gardening community. Within this community I want to understand who is growing unusual edible plants, and why (or if you’re not, why you don’t).

For the purposes of my project, I am defining ‘novel crops’ as those that are not grown on a commercial scale in the UK, but that make an appearance in home gardens and allotments. That’s a pretty large group of plants (everything for heritage and forgotten vegetables right through to exotic herbs and fruits) and so for the main part I will be concentrating on two that I am familiar with – Achocha (Cyclanthera species) and Oca (Oxalis tuberosa). Neither is farmed in the UK, but both have been discussed online for several years.

Although they’re both ‘Lost Crops of the Incas’, these two plants are grown, propagated and used in very different ways. Achocha is a vining plant, grown from seed. It’s usually achocha fruits that are eaten, although its young shoots and leaves are also edible. Achocha seeds have been available from the Heritage Seed Library and Real Seeds for a number of years.

Oca is a clumping plant, grown for its colourful tubers that can be used in similar ways to potatoes (although again, its leaves are edible). Oca is almost always propagated via the tubers (seed being very hard to produce). Real Seeds have carried them for a number of years, and T&M* started stocking them last year. This year oca is being promoted as part of James Wong’s Homegrown Revolution* range.

I suspect that many of the people who grow these plants pass on seeds or tubers to others, and that they are widely distributed through what an anthropologist would call an informal network :)

I am interested in how people source planting material for these species, and what other novel crops they grow. I am interested in how people learn how to grow, harvest and make use of these plants, and how that information is then passed on to others via social networks.

I am in the process of putting together an online survey and I will therefore be recruiting UK gardeners who are growing achocha and/or oca this year, or who have grown them in the past, and who are happy to take part in my research. I will be posting more information as I go along, but in the meantime if you think you would like to take part and would like me to tell you when the survey is ready, please leave a comment below or get in touch via Facebook or Twitter or send an email. I won’t use your contact details for any other purpose, and you will be able to fill in the survey anonymously if you should so desire.

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*Those are affiliate links. If you click through to those websites and subsequently make a purchase, I will receive a small percentage of the sale. It doesn’t cost you anything, and you would be helping to support a pennilless student, but if you’d rather not click those links then you can navigate to the websites yourself.

Pollen specimens at the Oxford University Herbarium

We’re halfway through the April Blog Love Challenge! Here are the blogs I have commented on today:

1. In my Iraqi kitchen has a fascinating post on Cattails in the Marshes of Iraq.


2. Anni’s Perennial Vegetables has been looking into ingredients for a new perennial vegetable patch.


3. The Extreme Gardener has been experimenting with three ayurvedic herbs for cold climates.


4. The Galloping Gardener has sent back a lovely photo blog from Uttarakhand in northern India.


5. And the Cheap Vegetable Gardener has been getting some help from a toddler, but not the good kind: Beware of toddlers and seeds.

That’s all folks!

Welcome to Day 14 of the April Blog Love Challenge! I didn’t reach my goal yesterday, but today is a new day (and the sun is out!). The blogs I have commented on today are:

1. Israeli Kitchen, who has been Rambling through Ramleh market.


2. On the basis that a newspaper column is just a blog that gets printed, I am including Alys Fowler’s lovely one in the Guardian which I always read but hadn’t yet commented on. Yesterday she was talking about being partial to parsley, which I am.


3. The Urban Veg Patch has declared spaghetti squash to be good winter veg.


4. This time last year, Toad’s Garden was producing salted ramsons.


5. And Soilman has pointed out that they didn’t have Pumpkins in Pompeii.

That’s all folks!

Welcome to day 13 of the April Blog Love Challenge! The blogs I have commented on today are:

1. The Veggie Patch Re-imagined is talking about invasivores – weeds you wouldn’t plant, but can eat.


2. Japan Farmers Markets shows you how to turn an egg box and a plastic bag into an egg carton greenhouse.

That’s all for today :(

Welcome to day 12 of the April Blog Love Challenge!

1. For those of you who follow this blog (and others) using Google Reader, VP has come up with a great summary of Google Reader alternatives so that you’re not left bereft when it ceases to function.


2. The Graphics Fairy blogs a free, printable, vintage every day – many of which are botanical in nature. Today’s is a stunning pink water lily.


3. You can’t beat a dose of botanical nerdery in the morning, and Weeding the Web delivers with a discussion of phyllody in ‘Malvina’ strawberry plants.


4. Urban Plants Research has been cooking spring, like you do.


5. And Alternative Eden are turning their hands to Ornamental Edible Exotics this season.

All done for today!