Category Archives: roof gardens

French roof top farms to supply 1000kg a week

Paris roof top gardens could soon supply 1000 kg a day of fresh food. Think of the food miles saved. Think of the air miles saved! Think of the taste of really fresh food that you can normally only get by growing your own.

The downside is that it is aeroponic growing. There is no soil or other growing medium. The nutrients are in water which is sprayed on the roots of the plant and continually recirculated. It works well and can produce high yields. The downside is that aeroponics uses chemical fertilisers which are made using fossil fuels resulting in a big carbon footprint.

Some vertical growing systems use a synthetic growing medium like rockwool or vermiculite. The production of both is extremely energy intensive. There are also issues around disposing of used rockwool. Again, far from sustainable food production.

No quick fixes are ever as easy as they appear.

Early protected cropping – growing plants in large open ended glass jars. It worked!

It can only be a half-way house the ideal being getting back to the market gardens that used to surround Paris.

The usual shop bought lettuce

Ever wondered where those bags of bright green lettuce come from? The answer is from massive fields harvested by big machines.

Notice how perfect they are. How is that done? The answer is simple by repeated application of pesticides including insecticides and fungicides plus lots of artificial fertiliser to make then look very green.

Modern pesticides are systemic which means they get into every cell of the plant. They are designed to poison any insect that bites the plant. Systemic pesticides cannot be removed, no amount of washing will get them out.

The government sets the maximum amount of residual pesticide for each pesticide in common use. But there will a cocktail of different pesticides in every plant. There is no limit to the number pesticides used. There is little research as to of effects on human health of regularly consuming  pesticide cocktails, even if the residues for each individual chemical stays within the limits. Nobody knows how they might react with each other. Things are changing as concern grows about the food we eat, see this report.

Lettuce are fed a lot of artificial fertiliser to ensure that they grow quickly and look very green. That produces more problems. First, not all the fertiliser is used, the surplus is washed into ditches, then rivers and then the sea. Excess nitrogen in water is a big problem yet is virtually ignored.

The other concern is that the soil used on farms has become depleted. It does not hold together well so get washed off in heavy rain or blows about when it is dry because it contains very little organic matter. Soil loss from erosion is a massive issue for the UK and the world with a prediction that we only have about 40 years of topsoil left. What then?

When the lettuce will be ready to harvest they are picked by hand and packed into plastic bags ready to be shipped to the retailer. Supermarkets will control the whole process from telling the farmer what variety to grow, how to manage the crop and how many bagged lettuce they want on a certain date. The field becomes an extension of the shop floor, part of a mass production process geared to make the maximum profit for the retailer.

All this because consumers have been led to believe that the cheapest, mass produced factory food is best. Bur cheap food comes with hidden costs –  read about mineral deficiencies in modern food.

People often ask why bother to pay the extra for organic produce. The answer is simple, choose food that is grown in rich fertile soils without the use of pesticides that produces more nutrient dense food that is much more sustainable or stick with factory farming. It’s you choice!

Our first lettuce of the season, grown in soil with absolutely no chemical pesticides!

This is a link to a lettuce table we made a few years back where you can grow your own even without a garden. We are about to make another so stay tuned – video to follow.

Urbanites find solace in urban farming amid COVID-19 quarantine

This is an article from The Jakarta Post and is typical of what is happening in many parts of the world.

There is a huge increase in the number of people wanting to grow food. In the UK seed merchants web sites are over loaded with some having queuing systems and time limited access. Well known brands are have sold out of seed but don’t forget there are local garden centres offering a telephone/email ordering service and home delivery.

We are experienced, committed and qualified gardeners and are happy to support and encourage anybody to grow food. Please email us info@organicgarden.org.uk

Crouch End supermarket grows vegetables on its roof

There has long been a need in the UK for the recognition that flat roofs can be used to grow food. Rooftop gardens have become a common feature in North American cities as well as in Asia and other countries where land for growing food is scarce. So it was with some joy that I approached this article on the BBC web site.

A supermarket in Crouch End, London is growing food on its roof at last.  They have about 450 square metres of space which has been turned into a food garden. The owner calls it a “… a farm on top of a supermarket” which I think is stretching things a bit; a garden yes but I do not know of any farms with just 0.045 hectares of land. Another quote says the project has a very low carbon footprint because all the equipment has been donated. Nice idea but plastic compost bins and other stuff have to be manufactured and transported to the site so do have a carbon footprint even though somebody else has paid!

Not that I am criticising what they are doing, I have long argued that using city roofs to grow food is exactly the way to go. There are some superb examples around the world where aerial gardens work well. In Singapore Changi hospital grows food on its roof and uses it to feed patients. Not only does that use what was redundant space it also give patients healthy and tasty food and maybe even saves money.

Many of the projects use hydroponics which, at the present time, use fertilizers which are not sustainable i.e. they are made from oil and use huge amounts of energy in the production process. Some argue that there is nothing wrong with that as long as it feeds people but the argument is that it relies on heavy imports of nutrients which is both unsustainable, costly and does nothing to address the issue of climate change.

There are alternatives like growing in containers using peat free, or home made, composts and making nutrients from composting food waste. Some years back a really innovative project in Australia tried to use a continuous worm composting system to make nutrient rich compost from restaurant food waste. The idea was to grow leafy crops in the compost on the roof which would then be used in the restaurant thus completing the nutrient cycle. There was never any news of whether it worked but technology has moved on now and such a project would be perfectly viable.

For me any food grown on rooves, or in gardens, has to be organic i.e. not just free of pesticides but sustainable. That means no artificial fertilizers. I would really like to see some innovation in plant based nutrients and container growing which would produce a sustainable system that is low maintenance and productive. That would also have to include some way of watering automatically triggered by sensors when the compost dries out. There are easy ways to do that it just needs the will and vision to see an alternative to existing growing systems. And a nice big flat roof!

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