Garden Tool Set: heritage potatoes

Showing posts with label heritage potatoes. Show all posts

Monday, August 10, 2015

Spuds you like

We were filmed by the BBC on Sunday. Zia, in her nervousness, forgot to get her wellies on. She doesn't always garden in Kurt Geiger heels! Watch us next Sunday on BBC breakfast news talking about potatoes and Pop ups!

Zia Mays

The Secret Garden Club met on Sunday February 26th to discuss potatoes - including a look at heritage varieties, some tips on growing in restricted space and how to raise a successful crop out in the open ground. The afternoon began with a potato vodka cocktail garnished with potato crisps before moving out into the garden.

I'm afraid I drank it before I could take the picture! But revelation! Potato vodka is soo much smoother than grain vodka. I bought Chase, the only potato vodka available in the UK.

There are something like 450-500 varieties grown in the UK, but only a few of these ever make it into the shops. To find some of the more unusual potatoes, you’ll need to look online for mail order suppliers, at Farmers’ Markets … or grow them yourself.

Clockwise from top right: Golden wonder, Orla, Salad Blue, Highland Burgundy, Mayan Gold, Pink Fir apple (centre left). Am I the only person that didn't know Golden Wonder crisps were named after the variety of potato? (MsM)

On Sunday, we looked at some heritage varieties all grown in the UK, but generally only available to grow or from specialist suppliers such as Carrolls.

Highland Burgundy – a close relative of ancient South American potatoes, but this particular strain was probably cultivated around 80 years ago.
Mayan Gold – these have been bred specifically in Scotland from an ancient Peruvian potato, Solanum phureja.
Salad Blue – the deep blue colour comes from anthocyanins in the flesh. Bred by the Victorians in Scotland
Golden Wonder – a very floury maincrop potato. Great for baking and chips … and used to make potato crisps!
Pink Fir Apple – originally imported into Britain in 1850 and bred for its fine flavour. Unusually, it’s a maincrop potato which boils well and is great for salads.

Here they are cut up: amazing colours!

Potato jargon

Terms like waxy and floury refer to the texture of the potato. Waxy potatoes have the texture you associate with new potatoes and potatoes in salad. Floury is that fluffiness you get inside baking and roasted potatoes when cooked.

These textures are determined by the water content of the potato. A high water content makes for a waxy spud. High dry matter makes the potato floury, and floury potatoes are generally not good for boiling: they will break down in the pan.

A common complaint of potato growers is that the potatoes break down in the pan when they boil them, even if they are Charlottes, or another salad type. The likelihood is that the growing conditions were just too dry – they didn’t get watered often enough.

The terms 1st Early, 2nd Early and Maincrop are often used to describe seed potatoes and simply refer to the amount of time take to mature.

First early potatoes produce usable tubers in 100-110 days after planting;
Second earlies in 110-120 days;
Early maincrops after 120-125 days;
Maincrops produce tubers after 125-140 days.

So, for example, you can plant early potatoes in late summer in order to have freshly dug new potatoes on Christmas Day. They are still early potatoes, regardless of the type of year they are planted.

There’s no doubt that growing potatoes in the open ground, whether a garden bed or an allotment, takes up a lot of space. And a lot of space is usually something the urban gardener doesn’t have.

However, you don’t have to grow them in the open ground at all. You can grow potatoes in a container. Because of the way in which potatoes are looked after while they’re growing, the best type of container to use is a strong sack … or indeed, a bin liner.

You might have seen advertisements in the Sunday magazines for special potato sacks, but you don’t need them. A nice strong black binbag will do. Or a compost bag, so long as it has that black lining inside. The black lining is to keep the light out, so that the potatoes inside don’t go green.

Growing in a container

The potatoes we planted in the compost bags on Sunday are a variety called Lady Christl and they are my favourite new potato. They are always ready nice and early, they have beautiful, unblemished yellow skins and creamy white flesh. The potato is firm with a delicate nutty flavour and they make a delicious salad.

When we planted them, the Lady Christl potatoes had little shoots emerging. This means the potatoes have been chitted, ie, stored in a light cool place so that the shoots develop. Note, a light cool place. If you want to store potatoes for eating, keep them in the dark. If you want to store them before planting, keep them in the light.

It’s not essential to chit potatoes but it does get them off to a head start in the ground. It also helps you when you’re planting them out as you can see where the shoots will develop and plant them the right way up.

Each compost bag will take three seed potatoes, seed potatoes being the starter which will grow into new potato plants. From each seed potato you should be able to harvest around eight or nine eating potatoes.

It’s not just the space-saving aspect: there are lots of advantages to growing potatoes in a container:

Less hard work – no digging;
Portability 1 – if you get a bad weather warning (eg, frost) when the plants are young and tender, you can move them indoors/under cover;
Portability 2 – you can place the bags more or less wherever you like.
Less risk of disease – your purpose-bought compost shouldn’t be harbouring blight spores, eelworms or any other nasties;
You don’t need to dig out the potatoes with a fork or spade, so there is little or no chance of damaging the spuds when harvesting;
Gardeners often miss very small potatoes and leave them in the ground over winter. By growing them in a bag you can ensure you harvest your entire crop.

1) The first thing to do is to put about three inches of compost in the bottom of the bag, spread evenly. Make it easier for yourself by rolling the sides of the bag down so that your bag is about six inches tall. You’ll want the sides rolled down anyway after you plant the potatoes – if you keep the bags at full height your potatoes will never see the sun and they won’t grow.

2) Next you want to take a sharpened pencil or sharp stick and make some drainage holes in the bottom of your potato bag. This is very important – you do not want waterlogged potatoes. They will rot, and they will stink while they’re doing it.

So, make about 5-6 drainage holes at the foot of each bag.

3) Now place three potatoes into the bag. Space them out evenly.

Always use seed potatoes, ie, bought from a nursery or garden centre specifically for growing. Seed potatoes should be guaranteed free from viruses, which culinary potatoes won’t be. Potatoes in the shops may have been sprayed with a shoot suppressant.

Potatoes in the shops may not have been grown in the UK and so may not be well adapted to grow here. Many, if not most, of the seed potatoes grown in the UK come from Scotland and are bred to grow well in our conditions.

4) The potatoes should go into the sack with the chits uppermost.

Yup, see them little roots...they go upwards, those will be the shoots growing above the ground to grab some sunlight for the plant.

You can grow potatoes without chitting them first but they take longer to get going. You can also cut seed potatoes up into divisions each with its own little chit and plant them individually, but you do get bigger plants and more potatoes by planting the whole spud, chits and all.

5) Once the potatoes are in, cover them with more compost: aim to have a layer of compost about 2-3 inches thick over the chits.

6) Finally, water them lightly. They don’t need to be soaked. Check that water is seeping out of the drainage holes.

7) Put the potato bag outside somewhere light and somewhere reasonably sheltered.

You’ll need to bring the bag inside if a frost is forecast. It’s not unusual to get frost in March in London; much more unusual in April, although we’ve had late frosts in each of the last two years.

8) After about 2-3 weeks you’ll see the dark green leaves poking up through the soil surface. Once the leaves are about 3-4 inches above the surface of the compost, add more compost to the bag, until the green tops are only just visible above the soil surface.

You’ll probably need to starting unroll the sides to accommodate the new compost as well. This is an ongoing process. Every time the plant grows so that you have about 3-4 inches of stem and leaves above the surface, unroll the sides a little more and add more compost.

If it rains a couple of times a week, you probably won’t need to water them. But do check your compost: if it’s very dry, then water it. Make sure any excess water is running out through those drainage holes. If it rains a lot and you put your hand in and the compost is sodden, move the bag under cover for a few days to let it dry out a bit.

These are early potatoes, so will take about 100-110 days to reach maturity.

So, in about mid-June, you can put on a pair of gloves and stick your hand into the compost. If the lumps are still tiny, leave them longer. If you can feel that you have big potatoes, start harvesting.

Other signs are also useful: once the potato plant is flowering you can try digging up some spuds, or your deep green foliage might start turning yellowy and begin to wilt.

The best way to harvest here is simply to up-end the bag on to a surface and pick out the potatoes. Put the rest of the plant on the compost heap and spread the compost on your garden beds.

You can store your potatoes for quite some time. Don’t put them in the fridge (that will turn the starch in the potatoes to sugar), but do put them somewhere cool, dry and dark. If you keep them out on a rack they will go green, and they will start to sprout. Neither of these is any good for eating.

Growing in the open ground

However, there are good reasons why you might want to grow potatoes in the open ground, if you're lucky enough to have the space.

You will get higher yields, ie, more potatoes, from a plant grown in a proper bed.
They need less looking after – no fiddling around with bags.
A potato bed is more attractive than having plastic compost sacks around the place.

There is also a well-known maxim among gardeners that potatoes help to break up your soil. They’re a popular choice for growing in new territory for that reason. I have my own thoughts on this. I don’t think it’s the potatoes that break up the soil at all. I think it’s you, the gardener. Growing potatoes here in the open ground involves hard manual labour.

You have to dig a trench. You add organic matter, or fertiliser, maybe.
You earth up several times.
You dig deep again to harvest the potatoes.

So, yes, potatoes are a great crop for breaking up the soil. But it won’t happen by magic. It will be your hard effort that does the work.

One extra benefit of growing potatoes in new ground, though, is that they have big leaves and plenty of them, which makes for a good natural weed suppressant. Weeds tend not to grow underneath.

The first step is to dig a trench. Anywhere from 3 to 8 inches deep, say about five inches is best.

You might like to add some potato fertiliser to the bottom of the trench. It may well help to increase the yield. Fertiliser formulated for potatoes will be high in nitrogen, so any nitrogen-rich fertiliser will do fine. Incidentally, potatoes like slightly acid soil. If you’re gardening in London and you have heavy clay soil, you should be fine, as clay tends to be slightly acid itself.

The potatoes we planted on Sunday were Pink Fir Apples. This is a maincrop potato, and normally you would plant maincrops in April, and start harvesting in August or September. Planted this early, they will need some protection against cold.

Lay your potatoes, chits uppermost at the bottom of the trench. The potatoes should be 12-18 inches apart and the rows should be spaced 2ft apart. Water lightly.

Cover carefully with soil. Ideally you want to finish off with a little ridge where the plant will emerge – your first piece of earthing up (it also helps you to remember where the plant is as it takes about 3-4 weeks for the shoots to appear above ground).

Once the plant has two sets of leaves, start earthing up. Earthing up involves drawing, with a hoe, soil from the area between the rows to cover most of the stem of the growing plant. Earthing up encourages the plant to produce more tubers and keeps them in the dark. The developing potatoes will turn green if exposed to the light, and the green bits are poisonous. To get a good crop of healthy potatoes, keep them dark and undercover.

In practice, earthing up isn’t essential if you have other ways of keeping potatoes under cover. Mulching the crop with grass cuttings is one way to keep the potatoes that developing dark and it’s much less strenuous than earthing up. This is also practical because the potato plants are growing as the same as your lawn starts growing, so you will have a weekly supply of grass cuttings just when you need them.

Potato problems

Potatoes grown in open ground are also more susceptible to diseases and disorders.

Blight
Eelworms
Wireworms, slugs
Frost damage

Blight

Blight is probably the most common problem. It’s a fungus-like organism, which first shows up as brown patches on leaves and blackening of the stems. If you catch it very early and remove and burn the affected material you may be able to stop it from spreading down to the tubers underground.

Blight is prevalent in summer, from about July onwards, and will spread when it’s cloudy and humid – as it often is in July. If you grow potatoes in a garden and there aren’t many other potato growers nearby you may escape blight altogether – although beware as it’s the same organism that attacks tomatoes, so you also need to have no tomato growers in the vicinity. On an allotment it can spread like wildfire.

But there are preventative measures. Early potatoes should be ready by the end of June so should avoid blight altogether. Constant checking and removal of any blotched leaves will help check the spread.

There are also blight-resistant varieties of potatoes, notably Sarpo. Sarpo Mira is well thought of – again, not a variety you’ll find in the shops but a good one to grow.

Potato eelworm

You might also get potato eelworm cysts. You dig up the crop and instead of potatoes you have tiny white or yellow cysts on the underground stems. There’s no chemical treatment available: practise good crop rotation. Eelworms don’t move much so just because they’re in one bed doesn’t necessarily mean they’ll be in the next-door bed. Again, grow only earlies. They’ll be ready to harvest before the eelworm reaches the harmful phase of its life cycle. There are some resistant varieties: try Sante.

Wireworms and slugs

Wireworms will drill thin holes in your potatoes. They are thought to be a problem mainly when you grow on new ground, so constant cultivation should reduce wireworm attacks.

Slugs are more likely to be a problem if you leave the potatoes in the ground only digging them up when you need them. Try lifting and storing the crop all at once.

If slugs are a big problem, apply a nematode solution on the patch before you plant the potatoes.

Frost damage

Another potential problem which should be taken into account is frost damage – potato plants are vulnerable to frost and so can be affected by a late frost. There was one very late frost in London in May in 2010 – wiped out my early potatoes, and this year, I lost 2-3 plants to a mild frost in April.

That April the maincrop potatoes were still underground and hadn’t yet sprouted. They were fine. It was only the earlies which were affected.

Having said all this about hard work and diseases and problems, I’ve made growing potatoes sound like very hard work, and it’s true that they do require a certain amount of physical effort to grow outdoors.

But of all the problems I’ve outlined above, late frost is the only one I’ve ever personally suffered from.

And of course if you grow in a container, these problems shouldn’t arise at all.

Now is the right time to plant potatoes, with the weather and the soil finally warming up. Traditionally, gardeners planted their potatoes on Good Friday, which could mean a chilly March start for the tubers, or a warm late April and a race to develop to maturity. This year with the prolonged cold, we’ve had little choice but to wait until the latter half of the month.

The Secret Garden Club planted out its maincrop potatoes this weekend at our annual potato workshop, where we demonstrated not only how to grow in the open ground, but also how to grow them in a restricted space – good for growers with a small garden or only a patio area, maybe.

We concentrate on heritage varieties which are not readily available in the shops. Some of our favourites are:

Pink Fir Apple

Pink Fir Apple was originally imported in 1850 but was unknown in the mainstream for decades, only recently becoming fashionable. The tubers are long and often rather knobbly, which can make them fiddly to peel. (I usually don't bother and just scrub hard instead.) The skin is part pink, or brownish yellow with distinctly yellow flesh. Although grown as a maincrop for later harvest, the flesh is waxy with a good nutty salad potato flavour.

Red Duke of York

The tubers are large and round with distinctive crimson skin. The floury flesh has a creamy texture and a clear yellow colour, and is very versatile in the kitchen - it can be boiled, fried, mashed, roasted or chipped. The Duke of York variety has been around since the 19th century but the first red-skinned tuber was discovered in Holland in among a crop of white skinned potatoes in 1942.

Russet Burbank

A small russet or brown-skinned potato, rather like the russet apple. It has white flesh and holds its shape well in cooking. Originally developed in Lunenburg, Massachusetts, the variety is named after potato grower Luther Burbank). The original Burbank potato was identified in the 1870s; the Russet Burbank, with its rough skin, in 1914.

Yukon Gold

An Central/South American style potato – that very yellow flesh and buttery flavour is characteristic of American potatoes. Today Yukon Gold is mainly available in the US and Canada. Another versatile culinary variety and especially good for baking and mashing.

Salad blue

These unusual potatoes were first grown in Scotland in the 1900s. Both the skin and flesh is a deep indigo, tending towards purple, colour. The name is misleading, as the potato is best used in frying, baking and mashing rather than boiling up for a salad. It has a light, open texture and moist flesh with a mild flavour. The blue colouring is an anthocyanin, which is an antioxidant, and the colour remains after cooking. Together with Highland Burgundy, below, and a more conventional white-fleshed variety, they make the most fantastic multicoloured chips.

Highland Burgundy

The Highland Burgundy potato is so-called, it's claimed, because it was used to provide an appropriate colour to a meal for the Duke of Burgundy back in 1936. The flesh is crimson or red with a distinct ring of white just below the skin, and the colour stays fast in cooking. The texture of the flesh is drier and denser than that of the Salad Blue, but the Burgundy should be cooked in similar ways: fry, bake, roast or mash, but don't boil.

Having discussed heritage (or heirloom) tomatoes in our previous Secret Garden Club afternoon, it’s interesting to see that there are less rigorous guidelines for a potato to qualify as a heritage variety. A heritage potato is, broadly, one which has been around since before 1950.

After World War II mass production of potatoes was needed to feed the population. Varieties which were high-yielding and reliable croppers were preferred to some of the quirkier, less prolific types, and it's those same potatoes that you find dominating the greengrocer and supermarket shelves today. Many of the potato varieties which had been grown on a small scale before the war became neglected and continued only by a few specialist growers. The growing interest in organic growing and farmers' markets has brought them to public attention again.

There are registered heritage varieties which have been grown for generations: Pink Fir Apple, King Edward, Duke of York and Arran Pilot are examples of these. Then there are non-registered varieties which have also been grown for many decades, often on smaller farms and smallholdings. Varieties such as Salad Blue and Highland Burgundy come into this category.

There is a useful articles on heritage guidelines and varieties on the BBC's gardening blog.

Diner beware

It’s worth pointing out that the tubers are the only part of the potato plant that are not poisonous. Potatoes are a member of the Solanum, or nightshade family, as are tomatoes, aubergines, and, yes, deadly nightshade. When you see your potato plants in flower you’ll see the family resemblance.

Mayan Gold potato plant in flower.

Potato leaves, flowers and stems are all toxic. If you leave the plant to grow on after flowering, it will grow a small green berry on the central stem, which looks for all the world like a small green tomato. That’s also poisonous. So stick to the tubers, and spare a thought for Lords knows how many ancient Andean foragers who discovered the hard way which parts of the plant could be eaten and which couldn’t.

Growing in the open ground

Growing potatoes in the open ground takes up space. But if you have that space they’re an easy crop to grow. The hard work all comes at the beginning, when you need to get the ground ready for your tubers.

1. Buy seed potatoes to plant. You can try your luck with planting potatoes bought at the supermarket, but there are good reasons not to do this. Potatoes in the shops may have been sprayed with a shoot suppressant. They also may not have been grown in the UK and so won't be well adapted to grow here. Many, if not most, of the seed potatoes grown in the UK come from Scotland and are bred to grow well in our conditions. Seed potatoes should also be guaranteed free from viruses, which culinary potatoes won’t be.

With seed potatoes you get a huge variety to choose from – we like potatoes from Carroll’s, Thompson & Morgan, and also Sutton’s have a wide variety available.

Salad blue potatoes with 'chits' - the little shoots which have already sprouted.
These give the potatoes a head start once they're planted in the ground.

2. Place your potatoes somewhere light and cool (but not cold – the tubers mustn’t be exposed to frost), like a shed, to ‘chit’. Chits are the growing sprouts that will develop on potatoes stored before they are planted out. There are two good reasons to chit your potatoes: 1) it gives them a head-start when they go into the ground as the growing shoots are already developing, and 2) it will help you to plant them the right way up.

3. When you’re ready to plant out, dig a trench up to eight inches deep for each row of potatoes in your intended bed. Each row needs to be 12-18 inches apart.

4. Line the bottom of the trenches with compost – multipurpose or dedicated potato compost – if you think the soil is poor. Potatoes like slightly acid soil; if you garden on clay as we do at the Secret Garden Club, you should be fine as clay is normally slightly acid itself.

5. Lay the seed potatoes at the bottom of the trench, shoots facing uppermost, about 12 inches apart.

6. Cover with soil, adding in more compost if you think the soil needs it.

7. Try to create a slightly ridged finish to the row. This will help you remember where the potatoes have been planted!

8. In clay soil, the plants should only need watering in times of drought.

9. The potato plants should start coming through after 3-4 weeks. Once they are 3-4 inches clear of the soil you can start gently ‘earthing up’, drawing soil from between the rows to accentuate the ridge over the potato plants. You can cover the growing plants so that just the top leaves are showing through – don’t bury them completely.

10. If you find earthing up difficult, use mulch or compost to cover the plants as above. We use grass clippings a lot – the lawn always needs mowing around the time the potatoes need earthing up – which is a bit unsightly, but effective. The idea is that the developing tubers need to be in darkness, so earthing up, or covering with mulch ensures they are not exposed to the light.

11. After the potato plants have flowered, they will usually start to turn yellow and die back. This is a good sign that they are ready to harvest. Dig up a plant in a corner to check. If the tubers are tiny, re-bury them and wait a couple of weeks. If the tubers are a good size, start harvesting!

As a general rule, ‘early’ potatoes – the kind you often associate with summer and potato salads, like Charlotte, or Nicola - take around 13 weeks from planting to maturity. These can be described as first earlies, or second earlies - the latter takes about a week or so longer. Maincrop potatoes, often bakers and mashers, will be ready 15-20 weeks after planting. But note these are guidelines – and before anyone writes in, there are lots of exceptions: Pink Fir Apple is a maincrop potato which is fantastic in potato salad, Red Duke of York is an early potato that makes terrific mash. When you buy your seed potatoes, it should say on the label, or bag, what kind the variety is. The terms ‘early’, ‘second early’ and ‘maincrop’ refer to the time taken to mature: an early potato will be ready earlier than a maincrop.

Growing potatoes in a bag

And if you don’t have enough space for trenches and rows of potatoes, don’t despair. You can grow potatoes quite easily in a container, and a bin liner, a strong heavy duty bin liner like a rubble sack, will be perfect for the job. Early potatoes grow best using this bin-bag method.

1. Take a clean, heavy duty bin liner that is either black or lined black on the inside. It needs to be light-excluding.

2. Punch two rows of holes at the bottom of the bin liner with a broken pencil. These are your drainage holes, and they’re very important - the potatoes mustn't get waterlogged.

3. Roll down the sides of the bin liner to about 3-4 inches from the bottom.

4. Cover the bottom of the bin liner with a 2-3 inch layer of multipurpose compost.

5. Place three seed potatoes on the compost, space evenly, chatted shoots pointing upwards. On Sunday we planted the early variety Swift, a tasty salad-type potato which is usually quick to grow and mature.

6. Cover again with compost until no chits are showing.

7. Place the potato bin-bag outside, somewhere outside and unlikely to be disturbed by stray cats, squirrels or footballs. One of our guests on Sunday says they have a problem with squirrels and some protection might be needed here such as placing the bin-bag under mesh. Footballs is my own concern – I once came home to find my (full) potato bags being used as goalposts.

8. After 2-3 weeks you should see the green leaves appear above the compost. Let the plants grow until they have 3-4 good leaves, then add more compost to the bag so that the leaves are just showing above the surface. You may need to start rolling the sides of your bag up to accommodate the compost.

9. Keep adding compost when there is 3-4 inches of stem showing above the soil.

10. Water if the compost seems very dry. Left outside and with a couple of downpours of rain a week, your potato bags may not need watering.

11. After a couple of months, you should have rolled the sides completely up and have a bag full of compost and three healthy potato plants laying down lots of tubers. Leave the plants to flower and wait until the leaves start to go yellow and die back. You can check if your tubers are ready by sticking a (gloved) hand into the compost and feeling around for them. If they are very small, leave for a while longer.

12. If your tubers are ready to harvest, simply up-end the bag and sort through the compost for your spuds. Put the remains of the plant on the compost heap and re-use the compost – not for potatoes again, but for another crop or as a general garden mulch.

Monday, August 10, 2015

Spuds you like

One potato, two potato ...