Growing Underground

Image of a person tending to a hydroponic farm located in an underground tunnel by the start-up company, Growing Underground

​Once you have got the indoor-growing bug, there is almost no limitation as to where you can actually set up your indoor garden, and if you do it in the right place, the endeavour can even be quite profitable too. Just ask the founders of Growing Underground, who have recently set up an indoor farm over 30m below the streets of London in a disused World War II air-raid shelter of all places.  Crucial to its success is its proximity to lots of food markets and eateries allowing them to carve out a niche in London’s fresh produce market by producing ultra-fresh produce that tastes better and is more nutritious since only having been harvested just a few hours earlier. Growing Underground is the creation of Richard Ballard and Steven Dring, two entrepreneurs that spotted a gap in the London fresh produce market but they also have some pretty impressive directors on their board including Chris Nelson, a consultant well-known in the horticultural arena, and Michel Roux Jr., the chef patron of the Michelin-starred Mayfair restaurant, Le Gavroche. The growing tunnels themselves are located underneath London Underground’s Northern Line where the farm remains isolated from changes in seasonal variations in surface climate allowing produce to be grown year-round. In addition, the underground location is not accessible to typical farming pests and diseases so pesticides are unnecessary making the produce even more desirable. Unsurprisingly, the founders have opted for using hydroponics to make the system as efficient as possible and to dramatically reduce their water requirements, and LED lighting is used to optimise growing conditions while keeping energy costs down. So far, Growing Underground has been successful in marketing Watercress, Thai Basil, Red Vein Sorrel, Pea Shoots, Mustard, Red Amaranth, Garlic Chive, Coriander, Mizuna, Rocket, and Radish, and the company is doing so well that it just recently secured further funding to expand into yet more underground tunnels.

Vertical gardening – Coming soon to a work place near you…

Image of a type of vertical wall garden known as PodPlants

​Vertical gardening is slowly but surely becoming mainstream, even spreading to environments that one would not normally associate with much greenery like the work place. One such example are PodPlants which were developed specifically to cater to the office environment. PodPlants are 2.4m high sealed vertical garden modules that are designed to be free-standing and low maintenance. The units are made out of recycled ABS plastic but the walls of the unit are kept very thin making each PodPlants unit weigh in at only 20 kg which is unusually light given the overall size. They use a patented irrigation system developed by the creator where the exposed roots of the plants dangle within the device, and is based on the increasingly-prevalent aeroponics technology which feeds plants using an air-suspended mist of nutrient solution. One of the problems with many aeroponics setups is that they are also a breeding place for bacteria, but the inherent design of the patented PodPlants is designed to address this issue. As a result, plants grown in PodPlants are healthier allowing them to grow more vigourously. The PodPlants are very easy to install, with the only requirement that they be located next to a power socket - no additional piping or drainage is required as with other vertical gardens. One reason for the increasing popularity of plants in the work place is the recognition that they not only increase the health and wellbeing of their workers but also increase worker productivity as much as 15 percent! Now that’s a compelling reason for any company to install a vertical garden and why PodPlants are becoming so popular.

Hydroponics made simple

Image of the Grow Float, a simple table-top hydroponic system

​The Grow Float

​There are many ways to ‘grow your own’ using hydroponics but it is a fast moving area and new ideas are coming to the market all the time. The Grow Float is one such design that really shows how simple the technology can be. It essentially reduces hydroponics down to a receptacle for the nutrient-laden water and some floating baskets for the plants to grow in (you also need a water aerator but that is only used intermittently). The nice thing about the Grow Float is that it is so simple, you can almost just make your own DIY version, but part of the appeal of the official version is the 'polished' finish designed to look like a hip house plant that is comfortable on your kitchen countertop. It debuted on Kickstarter in 2014 and has since evolved into a small business for the creator. 

Image of the GrowGrip, used to provide physical support to plants in large-scale hydroponic systems

Another Kickstarter project, the GrowGrip, which is a new design for supporting plants in large-scale hydroponic systems is almost ridiculous in its simplicity. The GrowGrip units look like someone just did a quick cut out of some foam packaging (and maybe they have), but once you understand the idea behind it, you realise it really does solve an efficiency problem when growing lots of plants hydroponically, and it does so in such a simple way.

Even the astronauts are doing it!

Image of astronauts aboard the International Space Station (ISS) tasting lettuce grown in microgravity on the ISS

A recent report from NASA has seen the International Space Station (ISS) occupants eating some 'home-grown' red Romaine lettuce which has been cultivated as part of an experiment aboard the space station. Unsurprisingly, they are growing under a mix of red and blue LED grow lamps, but interestingly, they have also included some green LED lights in there too! The green LEDs however are there apparently for aesthetic reasons - to make the 'indoor garden' seem more natural to the astronauts. One has to wonder though, whether the green light might be actually detrimental to the growth as has been documented in some studies, and which might be an important factor when you are trying to optimise limited resources as any indoor gardener knows. Fortunately, this is just the beginning of a whole programme of experiments of in-station growing, which will see NASA engineers working on ways to boost the growth yield, and which might provide valuable information to us back on earth trying to grow indoor gardens. Another interesting feature is their use of a form of hydroponics that includes a synthetic growth media once again demonstrating, what we've known all along, that LED Grow Lights and Hydroponics are the way forward. The primary objective of the ISS experiment is to test systems that could eventually enable astronauts to cultivate vegetable gardens aboard spaceships and other extra-terrestrial structures especially since future space expeditions will be long-term affairs requiring the need for space travellers to grow their own food.  In addition, fresh foods are needed for health and nutrition since many vitamins, minerals and importantly, anti-oxidants start to degrade once fresh produce has been picked limiting the time for which it can be stored.

Farm in a box

​Yet another company to enter the domain of indoor vertical farming but with a twist is the appropriately named Freight Farms. They have opted for a more portable version of the indoor farm by housing it within the common shipping container. The containers use hydroponic technology, and as we know, this can bring about savings in water and plant feed when compared to traditional growing systems. The containers also employ LED lighting for maximum efficiency. The indoor farm environments are all controlled electronically through an app (isn't everything these days !?) maintaining container temperature and air quality at ideal levels for growth. The Freight Farms's containers are divided into two main sections for different phases of plant development, including a seed-starting and early growth section as well as the main growth area for mature plants which are grown in vertical columns to maximise container space. Unfortunately, the container farms are too expensive for the amateur gardener at just over $70,000 a piece but they may be appropriate for someone looking to get into the business of small-scale local farming. More recently, an established traditional Greenhouse supplier, Williamson Greenhouses, has just announced its own version of the shipping container farm, the CropBox. The Cropbox has less capacity than the container farms of Freight Farms but they are more affordable and can even be leased on a monthly basis.

The era of indoor farming is upon us

Image of front entrance to the AeroFarms company building, where the world's largest indoor vertical farm is housed

​These days everybody, it seems, is opening an indoor farm! The US company, AeroFarms, is the latest enterprise to hit the news with their soon-to-be biggest indoor vertical farm in the world. As with other iterations of the indoor farm, the idea behind it is to provide more nutritious fresh produce to the local population in a more environmentally-friendly way. It is well-established that as fresh produce sits after harvest, even when refrigerated, the nutritional content begins to degrade, so having to extensively transport produce from distant traditional farms is generally detrimental. In addition, indoor farms do not have to use fertiliser (in the traditional sense), nor do they need any pesticides as the plants are grown in aseptic conditions where pests are kept at bay simply by the plants being isolated indoors. One unusual feature of the AeroFarms set-up is the use of a technique known as aeroponics in place of the more commonly-used hydroponics technologies. So what's the difference? Aeroponics, as the name suggests, delivers water and nutrients to the plants by creating a mist in the air space around the plant roots. This is different from hydroponics which delivers the same feed as a watery solution that bathes the roots. Is aeroponics better than hydroponics? It is not clear. One thing for sure is that it is more difficult (and expensive!) to create an aeroponic set-up than to build a hydroponic system, so it probably won't be the preferred system used by us amateur indoor gardeners just yet.

‘Open-source’ hydroponics

Image of the Mini Farm Grow Box hydroponic system from

​If you are the DIY-er type (and you also happen to have a 3D printer lying around), then you might be interested in the 'Mini-Farm Grow Box' concept from where you essentially build your own compact hydroponics system from common household parts and a little bit of 3D printing. As an 'open-source' project, the design work has all been done for you and you just have to follow the build instructions after you have downloaded and printed the 3D parts. The most interesting thing about the kit is that it does not require any power to operate, instead relying on gravity to 'feed' the plants - so once assembled, it is just a matter of planting the seeds or seedlings and waiting for your next (vegetable) meal to grow! Of course, you still have to do a little bit of work topping up the reservoir now and then unless, that is, you are a true tinkerer and make it completely automatic by adding a mains water line and a nutrient dispenser to replenish it when it is running low - maybe that's asking a little much (!?) but then again that's why they call it open-source...

LED light recipes for optimal growth

Image inside one of the indoor grow rooms at the Philips Research Centre in the Netherlands

​Philips, the big electronics manufacturer, has just opened a research centre in the Netherlands that will study the optimal LED lighting requirements for different food crops, in particular, 'leafy vegetables, strawberries and herbs' as well as 'wheat and potatoes'. It is pretty clear that different plant types have different lighting requirements for optimal growth. Even in our own (amateur) grow diaries, we noticed that different plant species grew with differing degrees of vigour (or not) under identical LED lighting conditions and it was clear that there is much more to growing under LED lighting than just simply sticking a plant under an LED light. Interestingly, they say that their lights will contain 'blue, red and far red' which is not unlike many of the more amateur (and cheaper) LED lights available (although the video clearly shows white LEDs as well!?). One can only hope that their 'light recipes' will be freely available as a public resource as more and more of us switch to growing plants under LED lighting.

​For more information, see their press release.