These are the course notes for the staple food workshop we ran on the 18th of March which might interest some people.
What is a staple food?
For the purpose of this workshop, I am defining a staple food as any food that contributes a significant number of calories to your diet. I have given some details on the calorific value of some animal products as a comparison but I am mostly going to talk about crops that you can grow here. The purpose if this workshop is to enable participants to make informed decisions about about much of their food they can, and want to grow for them selves, how much space it will take and how much money they will save.
In deciding which staple crops to grow the following factors must be taken into consideration.
Availability of seed
Ease of culture
Yield
Processing and cooking
Nutritional value
Enjoyment
Cost of buying it
As well as calories crops contribute protein and other important micro nutrients but for today I am only going to consider calories.
How many calories do we need?
According to the FAO between 2005 and 2007, Irish people ate 3500 calories/day, similar to other Europeans, but in contrast to Eritreans who ate an average of 1500. Depending on who you ask, your age, gender and the kind of lifestyle you lead, you need diffferent amounts of calories, however most sources give it as between 2000 and 3000 per day. I have used 2700 as an average figure or and adults food intake, which gives a round figure of 1 million calories per year.
Staple foods that can be grown here fall into a few major categories, cereals, starchy vegetables, legumes, small grains, fruit, nuts, and oil seeds.
The potato is the easiest and most commonly grown staple food.
It is a starchy vegetable. Other starchy vegetables are winter squash, parsnips and carrots which can also contribute to a staple diet. Most other vegetables, although nutritionally important do not contribute many calories to the plate.
Cereals and dried peas and beans are not normally grown in gardens because they are relatively cheap to buy and difficult to process. Other small grains such as buckwheat, quinoa and amaranth are also possible. I have had most success with quinoa.
Of the legumes, peas, broad beans and runner beans are the easist to get to grow and yield. Dried haricot beans are possible and in good summers they yield well but in a year like last year they yield poorly.
I have no experience of extracting oils from seeds but I have grown Camelina and other brassica crops similar to oilseed rape, linseed, and sunflowers with a view to home oil production. As vegetable oil is the cheapest form of calories, it has been my lowest prioity in terms of food self sufficiency.
Fruits have a low calorific value generally, however apples do have a significant number are the most commonly grown fruit around here.
The calorific value of some common foods is shown below.
| | Calories/kg | 2,700cals in kg | 1million cals in kg |
| Potatoes | 750 | 3.60 | 1,300 |
| Cabbage | 250 | 10.80 | 4,000 |
| Apple | 585 | 4.60 | 1,700 |
| Wheat | 3400 | .79 | 300 |
| Winter Squash | 450 | 6.00 | 2,200 |
| Hazel nuts | 6550 | .40 | 152 |
| Dried legumes | 3400 | .79 | 300 |
| Quinoa | 3700 | .72 | 270 |
| Vegetable oil | 8800 | .30 | 113 |
| Egg | (12 large) 1400 | 1.90 | 700 |
| Beef | 1700 | 1.50 | 588 |
Yield and space requirements of crops
The best conventional wheat crops in ireland yield 10T/ha which is 1kg/sqm. They average about 7T/ha. Organic cereal yields average around 5T/ha. The yields of crops used in the table below are a result of a combination of my own experience and internet sesrches and should be regarded as a guide. They are the yields I would expect to get here, using organic production techniques. The beef yield is based on Teagasc figures for an organic grass only system. The egg yield is based on feeding 2.5kg of organic mixed cereals and legumes per dozen eggs.
Potatoes come out as top calorie producers per sqm and show that about 1sqm/ day should supply your energy needs.
Cereals and pulses need a bit more space, vegetables such as cabbage take about four times as much space to produce the same number of calories, and beef and eggs more than 10 times as much space. The hazel nut yield is based on Kent. I don’t know what yields could be achieved here.
.
| | yield/sqm in kg. approx | area needed for 1M cal in sqm |
| Potatoes | 3 | 433 |
| Cabbage | 2 | 2000 |
| Apple | 1 | 1700 |
| Wheat | .5 | 600 |
| Winter Squash | 2 | 2000 |
| Hazel nuts | .15 | 1000 |
| Dried peas | .4 | 750 |
| Quinoa | .3 | 900 |
| Vegetable oil | .8 | 560 |
| Egg | .12 | 5800 |
| Beef | .1 | 5900 |
Cost of food
The table below shows the cost of some items of food in online supermarkets at the moment. I have used the prices of conventional food as I cold not get an organic price for some things. It serves to compare the difference in price per caorie of different kinds of food. The first column shows the cost/kg and the second the cost of 1M calories . Here it becomes obvious why people do not grow their own flour, oil and pulses as they are so cheap. What also becomes noticable is how expensive vegetables are per calorie. Eggs and beef come out looking cheap in comparison.
| | price online supervalue/Tesco March 2012 in €/kg | Cost of caloriess in the supermarket in €/ 1M |
| Potatoes | .5 | 975 |
| Cabbage | Broccoli 5-10 2. | 8000 |
| Apple | 3 | 5000 |
| Wheat | (6/kg spelt) 1.1/kg | 330 |
| Winter Squash | 2 | 4000 |
| Hazel nuts | 16.6 | 2432 |
| Dried peas | (5.50 marrowfat )1.5 split | (marrowfat 1650) 450 |
| Quinoa | 7.6 | 1890 |
| Vegetable oil | 1.60 | 180 |
| Egg | 3.2 | 2240 |
| Beef | 10 | 5880 |
Growing Cereals
| Advantages | Disadvantages |
| Grow easily | Awkward to harvest |
| Versatile in cooking | May need drying |
| Store well for several years | Need processing, threshing dehulling, grinding. |
Wheat and barley originated in the middleast where they are sown in autumn and grow during the mild winter when most of the rain falls. The warm summers are spent ripening and hard dry grain is formed. In Ireland it is a challenge to get cereals dry enough to store. Most must be dried indoors when harvested. This can be done either passively, on a floor where it is not more than a few inches deep, or actively in a drier where hot air is blown through it. Oats and rye probably evolved as weeds in wheat and barley fields in cooler climates than the middle east. They are the hardiest cereals most adapted to the northern European climate. They are easier to grow than wheat, coping better with a poor summer by ripening quickly. Cereals can be sown in spring or autumn, and particular varieties have been adapted for both. All cereals make a good cover crop preserving soil structure, and preventing nutrient losses over winter and protecting bare soil. They are susceptible to crows and other birds particularly just as they are sown and also when they are ready to harvest. Cereals should yield about 5T/Ha under organic conditions. That is 500g/sqm. Sowing rates should be to give about 400 plants/sqm which is about 10-15g/m This should give about 600-700 ears/sq m
Growing cereals in a garden
Sow seed in September or October or in March or April, thinly, in rows 30cm apart. The soil should be clear of weeds. Cereals do not require high fertility to grow and infact too much nitrogen in the soil wil cause the plants to have waek stalks and fall over more easily. If they are being grown as a green manure they can be broadcast at a rate of about 25g/sqm. If possible protect from birds after sowing, with a net. A lower rate should be used for growing for seed. Keep well weeded by hoeing between the rows.
Oats can be used green for tea and oatgrass as well as mature and dried. For tea harvest when the seeds exude a white milk when pressed under a nail. Main crops of cereals should be harvested when the plants have turned brown and the seeds are no longer milky, or when the birds start to eat them. The plants should then be harvested by cutting them at the base, bundling them into sheaves and drying under cover. They can be threshed by running through a garden shredder, although this damages the seeds a bit or by banging the plants on the edge of a bucket or barrel. They then need to be winnowed in a stiff breeze to remove the debris. Oats need to be dehulled, steamed and rolled to make the familiar flaked oats used for porridge. Hulless oats may be simply soaked and boiled to make porridge or ground into flour.
Wheat and rye are usually used as flour which is produced by grinding it in a mill. Small hand mills are readily available but are really hard work to produce enough for bread making. However freshly ground flour is much tastier than flour that is old. The fats in cereals begin to go rancid as soon as the grain is ground and this affects flavour. Larger mills are expensive but make grinding your own flour a practical proposition. Spelt is a form of wheat and should be autumn sown.
Potatoes.
| Advantages | Disadvantage |
| Great yields | May not keep all year |
| No processing needed | |
Potatoes are the most productive staple crop you can grow in Ireland. They have nutritional value of about 750cals/kg and a surprising amount of protein. They need minimal care and attention, no processing other than cooking. Yields of 30 Tonnes/ha are normal in conventional agriculture and on a garden scale this is possible too. That is 3kg/sqm, (or a half stone), or 2,250cals, roughly enough food for an average person in a day. This means that by planting an area of 400sqm or 40mx10m (less than 1/10th of an acre) you could have enough calories for the year.
Potatoes like a rich fertile soil with plenty of organic matter, an even supply of water, and a good weeding early in the season. The flavour of potatoes varies with soil condition more than any other crop that I know of. Potatoes grown with too much fresh manure, seaweed or chemical fertiliser have poor flavour. I think the best potatoes are grown in newly broken up grassland, without any applications whatsoever. They are also good when grown with well composted manure. Some people have a problem with wireworm in grass but it isn't a problem here.
The most important factors when planting potatoes are getting them under the surface of the soil, keeping them weed free and earthing up. A good organic soil will hold enough water for potatoes and they should never need watering. Watering very dry soil, (in a tunnel for instance), causes potatoes to crack a sudden watering causes the tubers to expand so fast that the skins burst open.
On a garden scale you can just place them on the surface of the soil and pile compost and mulch on top, but it is important to keep a heavy mulch on top as if the new tubers are reached by light they will go green, and green potatoes contain poisonous substances. Alternatively you can prepare the soil by digging or rotovating and push them under the soil. The deeper you push them the less earthing up you will have to do, but the slower they will come up. I like to get all my potatoes in about now and if all the ground is not prepared, I dig a trench, put as much good compost in it as i can spare, and then the seed potatoes. I cover them up roughly and as they begin to come up I fork out any weeds between the rows. As soon as possible they need to be earthed up. This means moving soil between the rows, against the stems, to cover them but without covering too much of the leaf area. Bringing soil around the plants kills the weeds, and encourages the stems to produce tubers. It also covers tubers close to the surface preventing them from going green.
I space early potatoes about 30cm apart in rows 60cm apart and maincrop potatoes 40cm apart in rows 90cm apart.
Early potatoes come out of the ground from June to August so there is time to grow another crop after them. Leeks or spring cabbage make a good crop to follow potatoes depending on your rotation.
Harvesting potatoes is a satisfying job. Care must be taken not to stick the fork through them. So, insert your fork 30-40cm from the stalk and lever them up all around.
When harvesting maincrop potatoes for storage they must be sorted and the skins dried. Harvest all of them even the marbles as they will be weeds next year. Divide them into marbles and damaged potatoes for animals, small green potatoes that can be destroyed, slightly damaged potatoes for immediate use, seed for next year, and perfect potatoes, for storage.
Storage Potatoes need to be dry when stored and keep best in a cool environment, but will rot if frozen, so in ireland, unless you have a cold store, a cool shed or back kitchen is best. We keep them in the unheated back kitchen as it is rodent free. In cold weather potatoes must be covered by straw or other insulating material to protect from frost.
Selecting potatoes for seed.
You can save your own seed for potatoes if you are a bit careful. Potatoes suffer from viruses, which reduce yield and are not immediately obvious in the field. Plants with viruses may be stunted, have curled or yellow leaves and generally look poorly. Always select potatoes for seed from best looking plants. Seed potatoes are traditionally produced in Donegal and in high altitude sites where the aphids that spread viruses are absent. The potatoes for seed should be approximately egg-sized, but larger green potatoes can be used for seed too. The seed potatoes should be left in the light for a few days to harden the skins, but not allowed to dry out too much. If seed potatoes are stored at too high a temperature they will be come wrinkled prunes and use up all their energy supplies before they are planted. This is especially true for early potatoes that are programmed to sprout early. If you have room for them in the bottom of the fridge that will help hold them. As soon as they start to sprout they must be kept in the light or the sprouts will look for light and grow too long. They will then fall off when you handle them. A couple of weeks before planting, seed potatoes should be put n a cool bright area for the sprouts to develop. This is called chitting.
Quinoa
| Advantages | Disadvangages |
| Easy to grow | Saponins need to be removed from seeds |
| Very high quality protein | We are not used to eating it |
| Stores well | |
Sow quinoa in April, thinly, in rows 30cm apart. Keep well weeded. Thin the seedlings, until there is at least 10cm between plants. The crop should be harvested when the plants have begun to turn yellow and the seeds emerge from the heads when rubbed. This will be sometime in September. The plants should then be cut at the base, and bundled into sheaves. Drying should be completed under cover. If mature quinoa plants are left outdoors in damp weather the seeds may sprout in the heads. When fully dry, the seeds can be threshed out by running the plants through a garden shredder, or by banging them on the edge of a bucket or barrel. They then need to be winnowed in a stiff breeze to remove debris. The bitter seed coat must be removed before eating. This can be done by a combination of toasting on a dry frying pan, rubbing gently, soaking in a solution of breadsoda, and by rincing in clean water several times during cooking. Buzzing the seeds in water in a food processor is also supposed to work but I haven’t tried that yet.
Peas and Broad Beans
| Advantages | Disadvantages |
| Easy to grow | Indoor space my be needed for drying |
| No processing involved | Haricots will not yield well in cool summers |
| Keep well | |
| Good protein | |
How to Grow
Sow peas and broad beans for drying in March or April outside in rows, 40cm to 60cm apart. The seeds should be about 5cm apart and 2cm deep. Both like a moist rich soil and appreciate a generous amount of compost either dug in, or as mulch. Beware of slugs as they can decimate emerging seedlings.
Most pea varieties need to be supported on sticks or a fence. Check the height of the variety and erect an appropriate structure. Keep well weeded.
Harvesting
To save seeds from peas and beans allow them to mature fully. When the pods turn brown and crisp harvest them and allow them to dry completely. It the weather is wet or if broad beans are badly affected by chocolate spot, they may have to be harvested before they are fully mature. Then they must be dried as quickly as possible under cover. When the pods are dry they may be shelled out by hand. Peas are slow to pod by hand and Mike has adapted the garden shredder as a threshing machine. To do this he replaced the metal blades with wooden paddles. This is a lot quicker than hand podding, although there is a little damage to the seeds, some of which become split. Peas and beans can be stored in an airtight container when really dry. To test if they are really dry, hit with a hammer. If they shatter, as opposed to squash, they are dry enough to store in an airtight container. If they squash they need more drying.
Growing Drying Beans
Sow outdoors in May and June 20cm apart in rows 30cm apart. If beans are sown in cold wet soil they will not grow fast enough to get ahead of the slugs. The first warm week in May is best, and sowing can continue into the beginning of June. Keep well weeded. Dwarf drying beans do not need support. Most varieties can be used green as well as dried but this will reduce the final yield. Climbing beans both common and Runner need support and will grow 3m high. The seeds or plants should be placed at the bottom of the support poles. When a dry bean crop is harvested it is a lot heavier than a green bean crop that is picked regularly so a stout frame must be erected.
Harvesting
Dwarf bean plants should be harvested whole when most of the pods have turned brown. Drying can be completed indoors. It is better to cut off the roots so that soil does not get mixed in wth the seeds. Climbing beans mature over a long period and so the pods should be harvested as they mature and go brown. The beans can be shelled when the pods are crisp. This can be done by hand, or by threshing with a stick. Before storing check the beans are really dry by hitting with a hammer. Like peas they should
shatter, not squash
Pumpkins and Squash
| Advantages | Disadvantages |
| No processing needed | Need a good summer |
| | May not keep all winter |
Like haricot beans these like a warm summer. They will respond well to heavy manuring of the ground. Sow 2 seeds in a 7cm pot and keep in a warm place, in April or May. When the seeds have germinated, put in a bright place but keep pretty warm, for instance a south facing window sill or green house. Dig holes about 60cm apart where the plants will finally be planted out and fill them with well rotted compost, about half a bucket per plant. Plants should not be put out of doors until a warm spell in May, or June and protected from frost and slugs. Then plant out and water in well. The fruits whould be harvested before the first frost and cured indoors in a sunny warm place. They should keep for several months. If only one varietey of any species has been grown then the seeds can be dried and kept for the following year.
Maize/Corn
| Advantages | Disadvantages |
| Stores well | Need a good summer |
| | Not interestng to eat |
Again marginal in the Irish climate, however we have had success growing a short season variety called Painted Mountain.
Sow the seeds indoors in pots or modules in April or outdoors in May or early June. Corn needs full sun warm weather and plenty of compost in the soil. As the it is wind pollinated the plants should be arranged in a block with at least four rows of plants 60cm to 90cm apart. Within the rows the plants need to be about 30cm apart. The cobs are produced on the side of the plants with the corn-silk protruding. Pollen must land on this for the kernals to be produced. After the seeds have been fertilised they begin to swell and the silk dries out. This is when it is ready to be used as sweetcorn. For corn meal or seed corn the cobs are left on the plant until the plant dies back. Then the cobs are harvested and dried. The seeds are rubbed off the cobs and ground into flour. Small amounts can be done in a coffee grinder.
Growing your own fat and proteins.
The most common seed grown here for oil is rape seed. Also possible are more unusual brassica seed crops such as Camelina and radish which have been grown in the past for oil. They are easy to grow but hard to extract the oil, sunflower and nut oils are also possible but not easy. In many ways animals are an easier to produce. Excess land can be used to produce grass for cattle. Excess grain, milk and potatoes are also concentrated in a pigs and chickens. Cheese butter and meat all contain lots of fat and protein.
Rodents
All seeeds are susceptible to damp and rodents. They are best stored cool and dry. When they are really dry they can be put in rodrnt proof containers outside, or they cn be stored in a cool place in the house in bags. Unless you are sure they are very dry it is better to keep them in paper bags or sacks as they mey go mouldy in plastic.
and extremely envious of their new seed bank building
