Grow Your Own

by Angus Stewart

  There are some 200 million urban farmers in the world, supplying food to 700 million people – about 12 per cent of the world’s population.

  Urban farming provides for 30 per cent of vegetable consumption in Kathmandu, 50 per cent in Karachi and 85 per cent in Shanghai.

  Some 50 per cent of Asian urban households farm.

  Small livestock are an important part of city farming. For example, livestock are raised by 17 per cent of urban households in Kenya.

  The average Latin American urban family spends 1–1.5 working days a week on its urban garden and saves 10–30 per cent on its food bill.

  THE HISTORY OF URBAN FARMING

  Urban farming has taken many forms throughout the history of civilisation, from a survival necessity to a pleasurable pastime. It has its roots deep in human history, and in fact was the first form of farming in the Middle East’s ancient Fertile Crescent region.

  But let’s go back even further than that. Well known in Australia are Queensland’s Bunya Mountains, which were named after the majestic bunya pines. These trees grow huge cones weighing up to 10 kilograms, which are packed with highly nutritious nuts. Like many plants, bunya pines tend to bear heavily every second or third year. From ancient times, Aboriginal people would put out the word that a good season was coming, and men, women and children would come from hundreds of kilometres around to gather for the feast. The remains of the steps they cut in the trees to harvest the cones can still be seen to this day.

  Until the harvest was done, the Aboriginal people would remain sedentary – abandoning the need for constant movement in search of food. They were ‘urban’ – collecting together in a ‘village’ camp to swap stories and enrich their lives. Rumour has it they ensured some seeds remained so there were bunya pines around for future generations. Is this one of the roots of urban farming? There is a great deal of evidence to suggest that Aboriginal people were ‘farming’ in other ways, such as burning grasslands to promote plant growth in order to subsequently harvest the grain from the native grasses.

  The first farmers

  From excavations of ancient hamlets in Palestine, Syria and southern Turkey, we know that the first farms were close to – indeed, immediately next to – the houses where the people lived. Dating to around 7000 years ago, these sites feature the seeds of emmer wheat as well as the seeds and pollen of many different flowers, wild herbs and early vegetables. These were urban farms, not commercial ones, but over time the excess of food that they created led to the growth of larger and larger ‘villages’, then towns and very soon cities.

  Early farmers of the Middle East were the world’s first plant breeders, as they started to select plants with larger fruits, seeds and roots to create better and more productive crops. The archaeological record shows clearly that, with time, the grain size of wheat became bigger and plants held their seeds a lot longer, making wheat much easier to harvest. Today, building on the breeding work of several thousand years, we now have large-grained, nutritious wheat plants that do not shatter at all, but sit upright as they wait to be harvested.

  Meanwhile in pre-European America, the early Mayans were dealing with the rather infertile soils of Mexico’s Yucatán Peninsula. They gradually changed their slash-and-burn rainforest farming into a form of crop rotation of maize, beans and squash, a system known as milpa. The beans built up soil nitrogen levels, a nutrient vital for the maize in the next rotation, while the squash also used the nitrogen and could climb and scramble to maximise the use of space. Milpa was more than a system of farming – it was also a method of uniting the urban community.

  This Aztec petroglyph of maize is an elegant record of the crop that allowed early cities to flourish.

  Roman model

  Every Roman villa had a house garden that supplied all the things the great staple, wheat, could not: flavoursome food, essential vitamins and meat protein (derived from fowls and rabbits). The garden frescoes in the renowned Villa of Livia in Rome feature vivid renditions of fruits, flowers and vegetables, revealing not only what highborn Romans ate, but also the things that they most valued in life.

  The Roman villa model of urban farming most closely resembles the situation in modern industrialised countries. Staples such as wheat, rice, maize and millet are grown on large-scale farms, whereas house, village or community gardens provide essential complementary foods, gainful employment, recreational enjoyment and a sense of control of our destinies. Agriculture makes life possible, but horticulture makes it worthwhile.

  The ties that bind

  Urban farming, in all its forms, is remarkably resilient. The satisfaction our forefathers obtained from growing food and feeding their families is increasingly attractive to many people living in urban spaces, and they strive to reconnect with their past. Many of us are finding that we have to relearn the gardening skills and rebuild the plant knowledge that have been lost in the last two or three generations – but we take on these tasks with great joy.

  In Adelaide, South Australia, this coveted link to the past is celebrated every year during the annual olive harvest. Olive trees grow well in the alkaline soils and Mediterranean climate of Adelaide, and the early city planners had the foresight to plant these tough and useful trees throughout the city’s parklands and along roadsides. The city council has found it necessary to manage the harvest by issuing permits to pick olives, which prevents turf wars and the trampling of garden beds.

  Many extensive kitchen gardens beside old European houses and villas have been farmed successfully for centuries.

  THE BENEFITS OF URBAN FARMING

  This type of farming offers many different advantages, which range from small to large scale.

  HELPING PEOPLE

  Urban farming provides an enormous swag of social, health and therapeutic benefits for the individual. Growing your own food will save you money if it is done efficiently, especially if you use the nutrients found in kitchen scraps to feed your garden. It provides much-needed physical exercise and superb mental stimulation, and in community gardens there is the added advantage of social interaction – including the satisfaction of swapping and bartering away produce you have grown.

  Your produce is fresher and will generally have a better taste because it can be harvested when it has fully ripened and it can be eaten straight away. You can also grow edible plants that may not be readily available from retail outlets, such as heirloom vegetables and rare herbs. If you are environmentally conscious, then urban farming is also a great way to reduce your carbon footprint in an enjoyable and viable way.

  PROTECTING THE ENVIRONMENT

  Urban farming is a potent tool with which we can all get involved to create better environmental outcomes, and this will lead to cities around the world being much more sustainable. A decline in freight as well as decreased energy consumption during food production will curtail the demand for fossil fuels. Utilising local recycled water and organic wastes as fertiliser will reduce expenditure, as well as promote carbon sequestration on urban farms. Large numbers of individual urban farmers are also willing and able to grow a much greater variety of crops and heirloom species, thus ensuring there is genetic diversity among plants for future urban farmers who are likely to be operating in very different climatic conditions.

  Freshly picked produce from the urban farm reaches the table quickly, ensuring ripeness and great flavour.

  Growing your own food will save you money if it is done efficiently, especially if you use … kitchen scraps to feed your garden.

  CREATING GREEN CITIES

  On a broader scale, urban farming can bring significant benefits to whole neighbourhoods. Community gardens link diverse groups of people together, and this often reduces crime rates. School gardens empower students to be physically and mentally active, and they teach children lifelong skills in nutrition and growing food. Urban farming can also help to buffer microclimates within cities, reducing the ‘heat island’ effect that cities create due to their energy usag
e.

  Working in community gardens provides demonstrable benefits for both physical and mental health.

  WHERE CAN WE DO URBAN FARMING?

  Specially designed potting mixes are now lightweight enough to make rooftop urban farming a far more feasible idea.

  The human race is a very inventive species that is defined by its use of tools and technology, and this remarkable trait has long been applied to urban farming. While many urban farmers have traditional backyard plots or participate in community gardens, others are constantly refining and developing methods for utilising vertical and rooftop gardens as well as very small spaces, such as balconies and courtyards. Indoor cultivation is also a reality, through the use of artificial lighting and hydroponics – and technology is evolving rapidly to make these specialised techniques more environmentally and economically viable.

  In addition to parcels of spare land in highly populated cities, we are also looking to utilise peri-urban areas (regions that are destined for urban development in the future). All around our cities there are spaces that can – and already are – being used to grow food in a sustainable way.

  URBAN FARMING IN SOIL

  Most urban farming occurs in soil, but this soil can be vastly different from its natural state. In fact, soil scientists have a name for soils that have been greatly altered by human activities: anthroposols. Regardless of whether they have a tiny patch of land or they are part of a larger enterprise, urban farmers work to improve the fertility of their soil through the use of compost, fertiliser and mulch, hence adding to the area of anthroposols in the world. This is not a bad thing. Urban soils can be much more fertile than their rural cousins.

  With population densities increasing, yards are getting smaller and smaller in cities around the world. Clever urban farmers are thinking outside the square when it comes to growing areas, utilising the leftover space next to driveways, planting vertical gardens along fences and incorporating raised beds in paved areas and courtyards.

  On a broader scale, Europe is the home of allotment gardening. Public spaces have been turned into collective urban farms, where citizens have their own ‘allotment’ or plot of land on which they can grow whatever they want. In more recent times across the Western world, school and community gardens have followed this trend, setting aside tracts of land for students and community members to cultivate their own food.

  There are many unexplored opportunities in the urban areas of the world with respect to suitable spots for urban farming. Some of the most underutilised spaces are those along transport corridors, such as ‘rail trails’ and road verges. Parklands and old bowling greens are only now being considered as possible locations for urban farms.

  URBAN FARMING WITHOUT SOIL

  The advent of commercially available potting mixes and soil-less growing media – such as perlite and coconut coir – means that having no soil (or poor soil) is no longer a barrier for the urban farmer. ‘Protected environment’ houses (commonly known as greenhouses, glasshouses or poly-tunnels) enable urban farmers to extend the growing season of plants cultivated in soil-less media.

  In high-rise and heavily built-up areas, focus has shifted to using rooftops, balconies, patios and walls for food production. This requires the use of specialised containers, growing media and fertiliser programs that suit the unique microclimates found in cities and address the specific light constraints and wind issues of metropolitan regions. Whether you are growing crops in a bathtub or a sophisticated wicking bed, the use of pots and other containers allows you to grow edible plants in all sorts of cramped places.

  Taking soil-less cultivation to a whole new level is hydroponics, a system whereby plants are grown in an inert medium (such as pure sand or perlite), and the nutrients that would normally come from soil are supplied to the plants via a balanced liquid feed. This type of system is dominating the commercial production of fast-turnover crops, such as salad greens (for example, lettuce) and soft-leaf herbs (for example, basil and coriander). There are many advantages to hydroponics, not the least of which is that nutrition is not dependent on soil condition so it can be carefully controlled, and crops grown in hydroponic ‘humidicribs’ can be better protected from pests and diseases. However, running a successful hydroponic system requires an acute understanding of fertilisers, and there is often tension between the advocates of ‘organic’ growing and the heavy reliance on synthetic mineral fertilisers in commercial hydroponics.

  Most local councils approve of the use of road verges for urban farming, which is a great way to utilise land that usually lies dormant.

  As long as crops have access to sunlight, water and plenty of nutrients, they will thrive on urban farms of any size.

  A PRACTICAL GUIDE TO URBAN FARMING

  THE ENVIRONMENT FOR URBAN FARMING

  LOOKING AT YOUR SURROUNDINGDS

  The environment created by urban areas has a profound effect on farming in various ways, both good and bad. A basic understanding of what affects plant growth can enable you to adapt your conditions for optimum growth and maximise your crop productivity. Take some time to assess your growing environment for the following factors.

  TEMPERATURE

  The length of your growing season is largely determined by latitude, topography and proximity to the modifying effects of oceans. The further inland we go, and the higher the altitude we ascend, the greater the variation in temperatures between day and night, and the greater the potential for colder temperatures and frost. Topography is an important influence, as localised low spots in an area will tend to be more frost prone, given that cold air drains to lower-lying areas.

  Cities are generally much warmer than surrounding countryside. A major reason for this is that there are less plants evaporating water in urban areas. As water is evaporated, it causes a cooling effect known as the ‘latent heat of vaporisation’. Since water absorbs heat when it moves from being a liquid to being a gas, this consumes a lot of the solar energy falling on the plant, and cools it. A similar process was used in the days before the invention of the refrigerator to keep butter from melting in a meat safe – wet canvas surrounding the meat safe kept it cool as the water evaporated.

  In urban environments, less of the incoming heat from the sun is used to evaporate water via plants, and more of it ends up heating hard surfaces and the atmosphere. The reflection of solar radiation energy off light-coloured concrete or metal – it seems that every architect wants their building to be white or, worse, silver – heats the air above the surface. Energy that isn’t reflected off heats the material it hits, warming it so it then radiates its heat off during the night. This is not all bad news, however, as food plants usually love warmth and will grow very quickly in the warmer environments of cities.

  Stonework and pavers can be used in cooler climates to absorb and store heat during the day. This helps to moderate temperatures.

  Plants thrive in the warm conditions found in urban situations. Light-coloured buildings reflect sunlight, while dark-hued asphalt draws in daytime heat and slowly releases it at night.

  Crops and temperature range

  Provided they have enough water to evaporate, plants do best in warm environments – as demonstrated by the luxuriance of a tropical rainforest. Most food plants appreciate the warmth of our cities, and do very well in them. Growing seasons are often longer, and you can even grow subtropical species in cities as far south as Melbourne, Hobart and Adelaide. With a bit of protection, microclimates can be created anywhere in Australia.

  Each crop has an optimum temperature range, so comparing the monthly averages for your area to the growing requirements of the crops in which you are interested will give you a starting point. As well as average temperatures, you will also need to look at maxima and minima, because certain crops – such as pome fruits (for example, pears) and blueberries – need a certain amount of ‘chilling’ (the number of hours below 7°C, depending on the variety you are growing). Consequently, high-chill crops may not
be a good choice in warm cities. Also, some crops may suffer if maximum temperatures exceed certain limits, and there can be damage to yields.

  LIGHT

  Everyone knows that plants need light. But how much light does your growing area receive throughout the day, and also during the different seasons as the position of the sun changes between summer and winter? If you are on a slope, what is the aspect of your growing area? In the Southern Hemisphere, the north side of a hill, or a house, will be warmer and sunnier than the south side.

  Most people have observed that plants growing in low-light conditions are spindly and tall. This phenomenon is called ‘etiolation’. The tendency to grow tall in search of sunlight is a response to conditions in a forest, but it doesn’t always help the plant in a concrete jungle.

  Pear trees require hundreds of hours of temperatures below 12°C to produce a crop of fruits each year.

  Plants can grow with less than full sunlight, provided they get a few hours of direct sunlight a day, preferably towards the middle of the day. Below about 50 per cent of full sunlight – depending on where you live and how much sunlight there is – productivity starts to decline. Very few plants can live if they receive below about 10 per cent of full sunlight, and those that do live will not produce useful food crops.

  The main problem within urban areas is shadowing by buildings, which is sometimes referred to as the ‘canyon effect’. Picture yourself with a skyscraper to the east and another to the north (or to the south, if you’re in the Northern Hemisphere). The sun comes up, but you don’t see it. You get one or two hours before the other building shadow falls, and then you get three to five hours of full sun all afternoon – except if your neighbour to the west has a row of tall, thick trees, in which case you only get one or two hours in the afternoon. Your plants will get just enough sun to live, but they won’t thrive and yield well – and they will be weak and spindly, no matter how fertile the soil.