Exploring Mashua

mashua 2016
Mashua in polytunnel 2016

I grew this for the first time last year. I wasn’t sure what to expect, because I had never, to my knowledge, seen it growing. Usually these things can turn out a little disappointing, but mashua has been an exception for me. First a little about mashua. It is a plant grown as a food crop in the Andes in South America. Although we tend to think of South America as either desert or tropical jungle, in fact much of it has a similar temperature range to the UK. The altitude keeps it cooler and damper, at least in the west. This means, much like those from the Himalayan valleys, many of the plants find themselves quite at home in Britain. Mashua is a tuberous climbing vine closely related to the nasturtium flower, and all parts of it are edible – tubers, leaves and flowers. It can grow quite tall in a single season, but will die back to the tubers over winter. Typically these tubers don’t start growing until the day length is shorter, which can be a problem in our latitudes, since that is not until later in the autumn and it can run out of growing time, so have a reduced cropping potential. This was also the case for potatoes when first introduced, and daylength neutral varieties of mashua are now available, Ken Aslet being the one usually mentioned.

leaf stalks twining
Mashua leaf stalk twining

I got tubers from two different sources, the Agroforestry Research Trust, and Pennard Plants. I’m not sure what variety either of them are, but they look similar at a glance. Because I had so few tubers I decided to plant them in the polytunnel, although unless you are exceptionally exposed, they would probably do fine outside.  I used my usual slug protection of a cut off pot, although in my experience they don’t suffer too badly from slug damage.  The foliage is bronzed, and similar to a nasturtium leaf, but lobed. If you like nasturtium leaves in salads (which we don’t), you would like mashua leaves. They have a similar peppery flavour. The plants climbed happily up netting, sticks and strings. The individual leaf stalks wrap around in a rather endearing way. Towards the end of the season I did get flowers, but this was so late that they were frosted, and I didn’t get to taste them and there was no chance of seed. I couldn’t see when the tubers started developing, the lower part of the plants being obscured by other vegetation. When the tops died back after the first hard frosts at the end of November, I could see that the tubers were formed by the tips of new shoots burying themselves back into the ground, forming a mass quite close to the plant centre. I think that earlier in the year new growth from the ground forms climbing shoots, and later in the year they form tubers.

growth habit july 2017
growing mashua shoots July 2017
forming tubers
dug up mashua plant November showing developing tubers

When dug up the tubers were of various sizes ranging from very small – an inch or so – to maybe six inches and an inch or more broad. I was impressed by the yield considering I had basically neglected them.

harvesting mashua 2016
Harvesting Mashua 2016

I got one pound of good tubers from one tuber and three pound two ounces from the other tuber, not including some smaller tubers that weren’t worth eating. Since I only grew one of each source, I wouldn’t make any conclusions based on this. It may be that one got more or less watering, or more or less of some nutrient in the soil. If the same happens again on a larger sample I will let them know – apparently they can accumulate virus infections.  After planting they got no real attention, except trying to get a bit of water to them, but as usual I struggled with my water supply at various times in the tunnel, so they probably got a bit drier than they would like. Even so the yield was more than I usually manage from potatoes outside, not great by good gardener standards, but pretty good for me! In appearance they are a bit like the smoother sorts of jerusalem artichoke you get – pointy ended and a bit scaley. Creamy coloured with pinkish tinges, they are quite attractive. When tried raw – again they have that spicy radish taste of nasturtiums, and are firm with a crunch. We did not like them raw, but if you are a fan of radish, you might like them in a salad, or grated in a coleslaw. Cooked, the spicy flavour and much of the crunchiness disappears and they become quite bland.  One of the plants (the lower yielding one) appeared to be more spicy than the other, again this could be a factor of the way it was grown rather than the variety. We didn’t have a huge amount to eat, because I was impressed enough to want to save the best tubers to grow more this year, but we tried them stir fried with spices, in stews, and pot roasted with other vegetables and meat. S. said he’s happy to eat it again, so we’re sorted. I didn’t tell him that the South Americans regard it as an anti-aphrodisiac. Apparently it may have an effect on sperm count rather than testosterone.

Weighing mashua tubers 2016

I stored the best tubers in pots of compost in the shed. This was intended to keep them cool and frost free, but since some of the scrappy tubers I planted outside did survive and grow this spring, I may experiment a bit more with that this winter – I didn’t risk any of the good tubers, so am not that upset that several disappeared in the ground over winter. They started to sprout of their own accord quite early in the spring (by Skye standards), so they came out of the shed into the polytunnel to save them getting too leggy. Some were planted out around the garden. I have not given them supports to climb up, since I have read they do not do so in South America, rather left them to scramble over the ground to smother weeds. If I was growing closer to other vegetables, I might give them canes like runner beans. Some I have planted in the polytunnel again, since they did so well last year. I have planted them along the outer edges with netting to scramble up.
So far (end of July) the ones in the tunnel are climbing at crop bar level. They are getting watered when I water the rest of those beds (I have a trickle hose system set up), although I also try and give the corner ones a bit more water, since the hose system doesn’t tend to reach that well into the corners.

polytunnel 2017
Mashua in poytunnel up netting

The ones outside are more variable. I planted some in the tea garden below the barn, where it is quite open. Two out of the four appear to have been eaten by slugs (I didn’t give them any protection), the other two are still very small. Some of the ones in the dog resistant garden have also disppeared, but at least one is doing quite well and is climbing happily with the beans up the poles. I also planted some in the fruit garden. These seem to be doing better – one of those is one that over wintered. I suppose to be fair, I should have pampered some of those more, although the ones inside haven’t been particularly pampered either. At this stage I can’t say which will do better in terms of yeild. The ones in the tunnel have certainly put on more growth above the ground, and are likely to persist later, having a little more protection from frosts and winds. However the ones outside will get more moisture, which may be more significant….

outside planting july 2017
Mashua in fruit garden
dog resistant garden
Mashua in dog resistant garden climbing with beans

The only pests I’ve seen is a bit of slug damage, although I have read that like nasturtiums they can get affected by cabbage white caterpillars. Apparently in the autumn, voles can eat the tubers in the ground, but we’ll cross that bridge if we come to it. Overall an exiting new crop for me that appears to tolerate a bit of neglect!


Polytunnel Perennials

I blame Martin Crawford! I’ve got over excited again planning new plants for next year already. I know it’s too early, but I recieved an e-mail from the Agroforestry Research Trust saying that they are open for plant orders. I need to try and remember whether I’ve got some plants reserved. I think I wanted Toona sinensis (a tree that grows onion flavoured leaves) but they had run out last year. I know that I fancied some Stachys palustris – marsh woundwort. Since there was an article in agroforestry news about it, I expect I won’t be alone.
What I’m really getting excited about at the moment is the idea of growing more perennial plants in the polytunnel. I’ve got on quite well with the fruiting vines. I have a kiwi (Jenny SF) and a bramble (unknown) which came with the kiwi. I was growing the kiwi in Solihull and it was one of the few plants I brought with us. When planted in the tunnel the bramble grew too. I tried digging it out several times, but it kept growing back, so the third year I left it, trained it along some overhead wires and was astounded by the fruit it produced. They are lush and sweet-tart, just like blackberries should be, but are also of a good size. The vine is not thornless unfortunately, which makes for an anti-social plant in a confined space. The roots I dug out, have fruited outside in a good summer. They may do better with a bit more shelter as well, since the local brambles have so far been pretty similar in timing for me (but much smaller). I also have a grapevine – boskoops glory, which I grew from a cutting of the vine I had on the veranda in Solihull. I don’t think it would crop to any extent outside here, unlike in Solihull, but is doing pretty well in the tunnel. I have a white grape vine also, which has yet to fruit for me. It seems to be growing well this year, so maybe next year I might get some fruit. I have also planted a couple of pineapple guava: Feijoa Sellowiana. As well as the reputed delicious fruit, which need a hot summer to ripen hence the polytunnel positioning, they also have edible flowers. I’ve not been able to try them yet, but they seem to be establishing OK near the lower doors in the tunnel.

inside polytunnel Jul08
looking downhill (east) July 2008
DSCN1807 small
looking downhill (east) July 2017

In the polytunnel when we moved in was a globe artichoke, which has produced some lovely flowers/buds. It hasn’t done so well this year. I did divide it this spring, so it may be that it is suffering from the damage and will take a while to recover, although being eaten by several hungry caterpillars probably isn’t helping! The offsets I planted outside in the fruit garden and at least two of them seem to be growing away quite well so far – we’ll see whether they survive overwinter. Also in the tunnel was an olive tree in a tub. I neglected it and thought it had died of drought, but when moved outside, it sprouted again from the base. I thought it was a privet seedling at first, and only realised the olive was alive when I tried to dig it out of the tub. Anyway, although planted in the tunnel soil this spring, I think that the tree is finally dead now. There are also a couple of marjoram plants as well, which I cut for leaves every now and then and seem to tolerate my neglect remarkably well. An aloe vera which had been on the window sill in the house, gradually getting taller and taller, is now also in the tunnel – not sure whether it will survive the winter however.
This year I planted my new apricot, which is doing well so far, and some kind of citrus, which was given to me as a rather spindly plant needing a good home. It has been grown from seed, and we are not sure what kind of citrus it is – will have to wait til it flowers!

New growth on unknown citrus in spring
Beautiful apricot leaves still growing at end of July!

I quite enjoy this kind of structure in the polytunnel, and outside come to that. I am very keen on plants that provide me with food year after year with only a little attention. Annual plants are far too liable to succumb to juvenile death due to overcrowding, slugs or lack of germination. So having been started off by Martin Crawford, I have been going through my various lists, books and getting distracted on the internet to try and come up with more perennials that will benefit from the shelter of the tunnel, and yet survive the winter and create a food forest. So far I’ve deselected again tree tomato / tamarillo: solanum betacea, pepino: solanum muricatum, Taro: colocasia esculenta var. esculenta and Eddoe: c. Esculenta var. antiquorum as being just too tender, although they all sound fascinating. I don’t (at the moment anyway) want something that will need moving indoors during the winter, and although we don’t generally get hard frosts we do get frosts that would penetrate the polytunnel’s protection.
So on my list of perennials to grow in the polytunnel are (in no particular order):

Grape (got)
Bramble (got)
Kiwi (got – but might like a kiwi berry – one of the small hairless ones)
Marjoram (got)
Apios Americana (got – maybe if it survives the slugs this year)
Chinese yam: Dioscorea batatas (got – ditto re. slugs!)
Asparagus (got)
Globe artichoke (got – but might fancy a different variety)
Chilli (got – survived one year on windowsill)
Passionfruit (need to source)
Ground plum: astragalus crassicarpus (need to source)
Aloe vera (got)
Runner beans (got – growing some heritage seeds library ones. I guess a few different ones would be required to see which over winter the best)
Yacon (got)
Fuchsia (got – fuchsia berry from my mum currently in a pot in the tunnel looking for a home)
Apricot (got)
Chufa (got)
Five flavour berry: Schisandra chinensis (got – but only one of the three plants seems to have survived, and you need a male + female for berries)
Korean mint (got – seedlings from a neighbour)
Sage (need to source)
Rosemary (need to source)
Licorice (need to source)
Blue sausage fruit: Decaisnea fargesii (need to source)
Honey berry: Lonicera caerulea (need to source)

Apricot training

This is not a timely post. I just thought I’d catch up with one of the new exciting plants I’ve got new this year. I’d fancied an Apricot for a long time. Although they probably would grow outside here if you had enough shelter, I’m still a long way away from that. However, I am growing more and more perennial plants in the polytunnel, so I thought I’d like to try it in there.
The plant was a present – a one year grafted whip of Early Moorpark Apricot on Torinel rootstock and was a good height, perhaps 4 feet tall. The first hard thing I had to do on planting it back in February was to cut it right down to about 1 foot tall! This is the exception to the general rule about pruning stone fruit only in summer to avoid silverleaf infection. According to the RHS “Apricots bear fruit on shoots made the previous summer and on short spurs from the older wood” and unless growing as a bush (which I thought would be impractical in the polytunnel) should be grown as fans. I rather fancied an espalier, but again that wouldn’t work for an Apricot. I found the RHS website very helpful in giving directions for training from scratch. So I planted, cut back and watered, and waited, hoping I hadn’t killed my lovely tree!

Newly planted Apricot
cut right back!

Sure enough, as promised, several new branches grew strongly from the trunk, which was a bit of a relief – I hadn’t killed it. The next step for me, was to put up some training wires. A little less straightforwards for a free standing fan, since I had no wall to come off. The arch of the polytunnel also meant that I couldn’t put in two vertical posts and string the wire between. I ended up using some random bits of wood we had lying around to create the framework. I had one nice vertical fence post by the centre path in the polytunnel, and one sloping bit as far to the side as I could manage. Since neither was in deep enough to take much strain, I have braced them with horizontal bits of wood before putting across the neccessary horizontal straining wires.
Then came another hard part. Again I had to cut back my lovely tree. This time the object is to select two branches to train in a 90 degree ‘V’ shape. I actually left two on the out board side since I couldn’t decide between them. Since then however, one has lost it’s leading point, so I think the decision has been made for me and I now need to prune that one out.

Framework and nicely branched Apricot
Newly trained tree

So far I am very happy with the health of my tree. It has grown well and has had no signs of any problems at all. Since it is undercover I need to keep an eye out for pests. Spidermite may become a problem. I have had this in the past on other plants in the tunnel and it really does stunt the growth. Also the soil I have is not very deep, generally less that two feet and usually less than that. I can’t do much about that. Since the polytunnel is slightly terraced (it slopes from end to end) I have put the Apricot in the downhill bed where the soil is slightly deeper, and I have been careful to water well but seldom, to encourage deep root formation if possible. Next year in the early spring, I will need to bite the bullet again and cut the leaders back again to encourage further branching to create more of the fan structure. I wonder whether I will get any blossom? Very exciting!