Grow Bristol

This article is about Grow Bristol an urban farming enterprise in Bristol. You will learn what makes Grow Bristol, a smart urban farm and how they look to deliver on a mission to grow food that is fresh, local and sustainable.

A Brief History

Grow Bristol was set up in 2014 bringing an approach to urban farming that was innovative and sustainable. By 2015, Grow Bristol had been given some land on which to grow food and to place the shipping container in which the food would be produced. The enterprise has been trading since 2016 selling microgreens into high-end restaurants and local retail outlets such as Better Food.

Hydroponics

Grow Bristol uses hydroponics. Hydroponics is a soilless approach to food production. Instead of plants getting nutrients from the soil, the plant roots are fed a water solution that has the nutrients they required added to it. As Grow Bristol grow in a shipping container, they use controlled environment agriculture (CEA). This means that the temperature, humidity and lighting are all managed to create the best growing conditions for the crops. The photographs below show how the growing area of the shipping container is laid out. You can see that the trays are stacked, which is the reason this type of food production is sometimes called vertical farming. The lighting used is light emitting diodes or LED lights.

The Sowing and Harvesting Room

Sowing and Harvesting

The sowing and harvesting room is separate from the growing room, and that is where we started the tour.

Harvesting takes place two days a week. Up to 100 trays of produce are hand cut using scissors each harvesting day. This provides about 12kg of harvest. The weight varies by crop so sunflower will produce around 0.5 kg per tray whereas parsley is around 50g. The day before the tour Grow Bristol had shipped a record 244 punnets to customers in one day.

Two to three hours are spent harvesting, then the next two hours involves packaging and sorting the customer orders out. Then finally the electric trike goes out, and deliveries take another two to three hours. The packaging used is vegware which is made from plants and is biodegradable.

Grow Bristol relies on unpaid volunteers and also paid internships from Bristol University.

Sowing is much quicker, and it takes about two hours to sow a hundred trays using untreated seeds. The wool they sow onto is industry standard. At this time the wool is not biodegradable although biodegradable options are being developed. One of the benefits of using a biodegradable option going forward would be the amount of compost that would be produced. This would help create a more circular growing system, whereby inputs and outputs are all reused.

Microgreens and herbs

The types of microgreens, shoots and herbs that are grown include pea shoots, garlic chives, sunflower shoots, parsley, fennel, dwarf kale, watercress, red cabbage, coriander, mustard and leek. I tasted them all, and they were all delicious. I enjoy the pungent, fresh hit of flavour from microgreens and shoots. Fennel was my favourite and garlic chive the pleasant surprise.

Trials

Grow Bristol have plans to scale up when a suitable location can be found, and they are keen to stay an urban-based enterprise. In preparation for scaling, they are trialling growing different varieties such as basil, a crop which would only make economic sense to grow on a scale larger than the current shipping container space.  There is also scope to do more tests and trials to optimise the growing conditions for each of the microgreens and shoots. The long-term ideal would be to grow baby leaf salads and vegetables.

The Growing Room

When you first enter the grow room, the first elements you notice are the warm temperature, the humidity, the rows of stacked grow trays, the constant hum of the fan and the eerie reddish light (produced by the LEDs).

The plant racks are all labelled with a date, the name of the product and a unique identification code so Grow Bristol can monitor the growth of each individual variety.

Grow Bristol uses an automatic lighting and watering system that can be controlled remotely from a laptop.

Flood and Drain Hydroponics

There are several ways to do hydroponic growing, and Grow Bristol uses a flood and drain mechanism. There’s water in a water tank with a nutrient mix dissolved in it that contains everything a plant would naturally take up from the soil (nitrogen, potassium, iron, magnesium, sulphites and nitrates). The nutrient solution is pumped up and along the shelves so that it soaks the mats on which the seeds and plants grow. After a certain period of time, the water drains away and is reintroduced during the next scheduled flooding and draining cycle.

Germination

The shipping container growing room also contains a germination tent. This is where the seeds are taken after sowing and before they are laid out on the vertical shelving.

The growing trays are laid out along the length of the container, and each of the varieties has a slightly different growing time. The growing times are just a few weeks.

Aeroponics

Grow Bristol is also testing aeroponics. Aeroponics involves hanging the roots in the air and spraying them with a mist of water containing a nutrient solution. This promotes root health compared to using trays that aren’t specifically designed for indoor growing with mats. The effects of aeroponics on yield and growing time are being monitored.

Reflections

Dermot and Adam were very generous with their time and knowledge during the tour. I’d spent a morning with curious, like-minded people who came together to learn and talk about what the future of food might look like in an urban environment.

Grow Better has won a few awards in the last two years: the Bristol Post Environmental Award, the Bristol Good Food Awards and the Bristol Lifestyle Award. They were also finalists in the Crumbs Awards. It’s great to see an innovative urban business getting recognition.

If you are interested in urban farming and the challenges facing starting up and running a controlled urban environment agricultural enterprise, then go along to one of Grow Bristol’s tours. The next tour is on the 11th of February 2018/ Tickets cost £10 and can be purchased on Eventbrite.

Grow Bristol’s story illustrates some of the challenges of starting an indoor urban farm.  And it also suggests that being willing to share information about indoor CEA will help more of these urban farms to take root in our cities over the years to come.