Bristol’s Ballast seed garden: a weighty landscape feature in the city


Ballast provides the inspiration behind the development of an unusual open space in the city of Bristol, a floating ballast seed garden built on an old grain barge.

Bristol was a city essentially built around maritime trade and ballast itself was a part of that history. Ballast is needed in order to help stabilise ships on voyages carrying cargo. This ballast was loaded into the bilge of ships with the cargo, the crewmen adjusting the weight of the ballast to get the correct floating stability in the water. In the early days of maritime history, crews would use anything they could lay their hands on, be it soil, rocks or gravel. Contained within that material was plant seed.

Nick Wray, curator at Bristol Botanic Gardens explained, “These materials allowed the chance for dormant seeds to act as unwitting stowaways on board and travel to far corners of the world. Once the ships had reached their destination, the ballast was simply unloaded and dumped on the quayside (often sneakily to avoid paying taxes) and the seed free to germinate.”

The 5-year project Seeds of Change: A Floating Ballast Seed Garden emerged from work undertaken by Brazilian artist Maria Theresa Alves as part of the Port City Project where she was investigating ballast flora from different port cities in partnership with the Arnolfini, Bristol’s Centre for Contemporary Arts. Born in Sao Paulo in 1961, Alves explores social and cultural phenomena concentrating on examining our own identities and social circumstances.

This project has been running successfully since its inception in 2012. It involves a number of partners from varying organisations throughout Bristol and further afield, the Arnolfini, the University of Bristol Botanic Gardens, Bristol City Council and in 2012 the London Olympics Festival with support from Bristol Harbour Authority.

Initially back in 2007, Alves researched sites around the city where ballast had been dumped on riverbanks, collected soil samples and propagated plants from sown seed. A number of different species included Calendula officinalis, Eruca sativa (rocket), Ficus carica (fig), Setaria viridis (green bristlegrass), Ecballium elaterium (squirting cucumber), Asphodeline liburnica (Jacob’s rod), Avena sativa (oat) and Amaranthus caudatus (amaranth).

During 2010, Alves was invited back to Bristol by the Arnolfini and Bristol City Council to embark on a design for a ballast seed garden. By chance, in 2011 a disused concrete grain barge was singled out as an innovative place to develop the garden. For decades, two grain barges had been tied up and rusting against Castle Park in the heart of Bristol city centre; being used as unofficial tips for rubbish. It wasn’t until a property was developed on the opposite banks of the river and the new residents complained to Bristol City Council (BCC) over the eyesore of the grain barges, that they came to the attention of Aldo Rinaldi, Senior Public Art Officer for BCC and he saw the potential to develop one of the barges into a garden for the city.


Getting the barge in ship shape and Bristol fashion

The barge selected is a giant concrete and metal structure measuring 24 metres by 9 metres and weighing in at 120 tonnes when empty. These particular barges were developed in the U.S, during World War II when there was a shortage of steel, hence the substantial bulk of concrete. They were meant for use as grain transporters with the primary aim that they would only be used once for an Atlantic crossing.

In 2012, the ballast seed garden design was developed by German designer Gitta Gschwendtner in collaboration with Alves, Nick Wray, Lucy Empson, landscape architect (BCC) and the Arnolfini technical department. Advice was on hand by engineers Ramboll UK and plant technical support from the University of Bristol Botanic Gardens.

Gschwendtner first and foremost needed to consider the aesthetic qualities and create a space that illustrated Alves’ ideas to represent effectively the garden as a conceptual piece of artwork.

“It was up to me to create something that showed off the concept, that was relatively neutral without too much fuss but at the same time telling a story and immersing the visitors into the experience”, added Gschwendtner.

There were a number of technical difficulties to overcome when creating a garden on a disused grain barge. For instance, the conversion of the barge was logistically quite tricky to carry out, as there is no pedestrian access to it directly. Also, the designers wanted to use sustainable ways to irrigate, light and power the structure. The complexities of the design process included creating a safe walkway and covering the hold. All plants needed to be transported using the harbour master’s boat and planting up still continues in this way today. Because of the barge’s location it is very prone to hot dry conditions and so careful considerations were formulated to overcome this. Water is pumped directly from the river passing through filters and into the planting beds via a system of piping with irrigation nozzles. The composition of the compost used also needed to be carefully examined with thought given to weight and depth of substrate. A nautical engineer advised the design team about these factors, as it was imperative that the barge did not list to one side. The compost needed to be light so a mix was made up of recycled domestic waste with bark chippings and a water holding polymer gel to prevent drying out.


The Stowaways

Photo credit: Max McClure

Photo credit: Max McClure

The design of the planting is in large swathes so that it can easily be seen from above as most people see the garden first-hand when peering over the wall from Castle Park. This also creates a greater impact in terms of colour, form, texture and shape of planting. The main period of flowering is from July onwards with planting taking up to two months from late spring onwards and seed is collected in the autumn for propagation the following season. The propagation of the plants takes place at the University’s Botanic Gardens before then being ferried out to the barge on special planting days. The compost levels are topped up every year so that plants do not become nutrient impoverished and this helps to keep weed growth to a minimum.


Visiting the barge and learning the ropes

The garden has been a source of inspiration for educational activities since the project’s beginning in 2012. Acting as a successful public engagement programme across the city and involving school trips, family planting days, boat tours hosted by botanists, historians, performers, local chefs and storytellers, the project continues to enthuse local communities. The barge has effectively acted as a shop window into the city and has attracted a varying audience of different cultures and ages. Over 2012 and 2013, schools across Bristol have built their own ballast seed gardens and grown plants from seed with advice from specially trained volunteers from The University of Bristol and the University of West England. Many of the artists involved with the Arnolfini directly, such as storyteller Andrew Loader and sound artist Matt Davies, formed part of the public engagement programme. The children could listen to wonderful plant tales and hear the amplified sounds of plants such as Venus flytraps as they crushed their flying prey! Many subjects were covered including the arts, history, science and literacy but often with an emphasis on local and global heritage. Some schools went on trips to the ballast seed garden and for some students it was the first time they had ever been on a boat.

Last year was a special one for the city as it celebrated being European Green Capital 2015. For the ballast seed garden, a programme of themed activities including themed activity days and tours were planned by the project partners starting with a family planting day in June. Because so many visitors were venturing to Bristol in 2015, it felt fitting that some guest ballast plant species were introduced into the planting mix on the ballast seed garden. Cathy Lewis, Botanic Garden Researcher was employed to carry out an extensive library exercise to look at the ballast flora of other ports including Cardiff, South Glamorgan, Pembrokeshire and Swansea. Six plant species were identified and used including Anagallis arvensis var. caerulea more commonly known as poor man’s weatherglass because of its tendency to close up when the sun is not shining, Echium italicum (Italian vipers bugloss), another Mediterranean species, and the corn marigold, Chrysanthemum segetum.

Photo credit: Max McClure

Photo credit: Max McClure

In addition to the new plant visitors, many important guests visited the Ballast Seed garden in 2015 including the Lord Mayor of Bristol, Councillor Clare Campion-Smith and the Lord Mayor’s Consort Mr Ian Campion-Smith.  There was also a return to Bristol by founding artist Maria Thereza Alves to the ballast seed garden where she saw for the first time the final design of the garden.  

Plans under way

With the 5-year project drawing to a close this year there are discussions about the future of the garden. On the opposite banks of the River Avon there are plans to develop the old brewery and a new bridge is being proposed over to Castle Park. As a result, the ballast seed garden will need to be move to a new location. This is currently being explored with all of the project partners but it is hoped that it will move further into the heart of the city where it will continue to contribute to the experimental arts and social fabric of the city.


All photos are credited to Max McClure