An August "slow morning" visit to OmVed Gardens in North London, with a demonstration from ceramic artist Lyson Marchessault on making wild-urban bricks.

Though Highgate is only down the road for me (or rather, up a hill), as I find with many other London garden spaces, I just can’t make it when they’re open. So, finally, on a hot August day I jumped upon the opportunity to visit the OmVed Garden for a “slow morning” and receive a demo from potter Lyson on making bricks using “wild” clay and straw from the site.

Lyson Marchessault is a French-Canadian and British artist based in London, primarily focusing on ceramics — under the guide of La Roche Pottery. Her work has an interest in ancient techniques and forms, incorporating folklore and ritual into raw materials and clay that she harvests herself from the landscape. Part of her practice also involves ecology, fermentation and regenerative art.

What I hadn’t pieced together before my visit, was that I had met Lyson already when she came to volunteer at the garden I work at. In fact, also later on interview for a trainee position too. But I’d also already seen her work on natural building techniques elsewhere. It wasn’t until my colleague said she recognised the name that all the threads joined up. It transpired that Lyson had found herself at OmVed for a spontaneous traineeship and it all worked out. I now have all my bricks in a row, and so had she, so to speak. [She’d also very nicely pruned the posh-looking espalier fruit trees, which was impressive to see].

Personal anecdotes aside, this was a delightful couple hours. It’s like when you look at a neighbour’s house and start getting ideas about what to do to your own; I’m currently advocating for similar galvanised steel planters for the front of our Grade II Listed building. What immediately struck me about the OmVed site is that it was very tidily managed, even when meadows and log habitats were left to their own devices. So perhaps a bit of envy that they were able to keep it looking trim when ours was a somewhat higgledy mudfest, but also satisfaction that North London could have this secret space.

Read on for more thoughts on the space, plus insight from Lyson’s demo on building wild bricks.

Urban clay.

This project was about hyperlocal materials; using clay from ground being dug up for construction works next to the garden, sand (I think also from the builders), straw from wheat grown on site and bulrush fibre from the pond. Combining these four materials, plus water, it’s possible to make bricks and also plaster for those bricks. With these, little stools were being produced. This is absolutely a project I want to try in my own space.

Making clay.

First is to obtain your clay. If you were using “wild” clay to make actual pots from (or objects, like I did at Groundswell 2024 with a fun clay sheep), you’d want to sieve your clay in order to remove rocks and maybe bits of pot in there, particularly if it’s coming from London land. For this brick-making, however, Lyson suggested there was no need to sieve it.

If you’ve ever done a soil test (or fancy doing one) it’s an interesting visualisation of what your soil texture is, and how the particles of clay, silt and sand interact. Clay is lightest/smallest so when in water, it’ll eventually settle at the top. Sand settles first, then silt, then clay.

Though it didn’t need to be clear, the clay did need to soften up by soaking it/keeping it covered in water. I’m unsure if any rocks etc do make their way to the bottom of the trug (plastic bucket), but it was clear from two example trugs that one had chunkier stuff and one had smoother stuff. When it feels softer, it can be mixed to make a smooth version. Presumably smoother means that all the good clay particles will have access to other ingredients and have more integrity; if it’s lumpy, the bond won’t be as great.

Images: 1. Clay being soaked in water; 2. Softer clay from being soaked in water is mixed to make it smoother; 3. Demonstration of the 1:1:1 proportions for making cob from clay, sand and straw.

Making cob.

Cob is a natural building material made from subsoil, water and a fibrous (organic) material such as straw. English cob was/is traditionally made using clay and chalk, both heavily present in soils — though it’s a technique found worldwide, with original human structures made from it. Being a thick material, it has a high thermal mass, particularly useful for homes that needed to be kept warm in winter yet cool in summer. Cob bricks can be made separately to build structures from, rather than cobbing directly onto a stone wall.

The proportion Lyson was using was 1:1:1 of straw, clay and sharp sand. These were combined and the straw was left to ferment. This would allow the lignin gum in the straw to break down so making the mix more sticky, and therefore better in bonding with the clay and sand. Fibre could also be added here to bulk up the mix (in a 1:1:1:1 proportion).

When combined and suitably broken down, it can be passed into a brick-maker. This contraption was something I believe Lyson had also made herself after seeing traditional ones. It’s a hollow wooden box made to fit over a solid wooden block, so that when the cob is compacted and dried, the outer wooden frame can drop to allow the brick to be released.

Images: 1. Buckets of sand, of straw, and of mixed clay-sand-straw cob; 2. Handling the fresh fermented straw, clay and sand cob mixture; 3. Cob mixture in a handmade wooden brick-maker being allowed to dry.

Making plaster.

Cob has an appealing colour and texture regardless. Warm brown and with lumps and bumps from sand and straw. But a plaster can be added to create a smoother appearance, and perhaps a different shade.

When our pizza cob oven was rebuilt, the master builder Frank had done multiple layers of straw cob to both fabricate a form and to ensure the thermal mass required for keeping a pizza oven toasty hot. Afterwards, he used clay and sand alone in a mixture to establish a smooth plaster layer, so keeping all the other layers nice inside.

These bricks were given a coat of lighter-coloured plaster. I don’t know if it was just the addition of the bulrush fibre that made this material a lighter-colour, or maybe it was in fact a different coloured sand? But sharp sand and clay were combined with the fluffy innards of the male part of a bulrush. This was smoothed onto each dry brick by hand. I don’t have any photos of finished brick, but I recall them being used to construct seating.

Images: 1. Lyson mixing a tub of clay, sharp sand and bulrush into plaster; 2. Lyson mixing the plaster mixture with tubs of straw, cob and clay, loose bulrush fibre, and cob brick in progress; 3. Smoothing plaster onto a dried cob brick.

OmVed Garden.

Growing areas.

Vegetable garden —

Firstly, I want those galvanised steel planters; I simply have a love of weathered metal. For their space, these raised beds allow for ease of movement around; ability to control the soil texture; protection from slugs (which I’m dubious about); and ease of separating the plants out for seed saving — which is a key function of their operation. They’ve got lovely willow (or hazel) arches over the beds that are home to pea plants. At the entrance to the site is an area they call the Willow Circle; an open area for gatherings underneath a willow.

Along with the pots of tomatoes in this section, on another concreted bit towards the back of the plot they have a further arrangement, all mostly these beefy Queen of the Night varieties, and similar. I’d like some of those seeds. The veg (and herb) choices were quite standard for an urban growing space; ones that could be left without detriment, would seed nicely, and also provide nice flowers for pollinators — such as peas, beans, lettuce, kale, mustards, rocket, fennel, dill, curcubits (with one that looked like a loofah type) and the tomatoes. However, sprinkled in were unusual (to English lands, but not today’s British tastes) crops such as acocha, amaranth, and tiger nuts.

Images: 1-2. View of the main vegetable garden area with raised circular galvanised steel planters, willow arch, and bushy plants throughout; 3. A purple-coloured beefy tomato, which could be a Queen of the Night.

Seed saving —

OmVed’s Seed Saving Network is a seed bank and community of seed savers. Seed sovereignty is useful for many purposes; for an urban garden it’s mostly about building resilience by choosing crops that have proven to be successful, but also growing and sharing cultural foods that may otherwise be difficult to access. It also saves funds because you don’t need to buy new, or there’s a swapping sharing economy involved. Yet, it’s also about education; seeing a crop through its full lifecycle with benefits throughout to wildlife (flowers for nectar and pollen, stems for overwintering insects) and then processing it, which takes patience and care.

Seed saving requires forward planning though; knowing the right time to harvest for viability, and being able to manage a space so that a crop isn’t accidentally removed too early. The photo below shows mashua climbing up a structure; this is just the plant’s habit, however, to anyone unfamiliar with it, this space could look messy, and that’s also a part of seed saving — holding back the need for neatness and order. Some crops are covered to avoid cross-pollination also, though additionally to keep away pests, such as is shown with the leek and celery below.

Images: 1. Mashua climbs up a structure; 2. Celery and leek bed is covered with a nylon mesh to deter flies and birds; 3. A hanging seed threshing net, full of various dried crops awaiting processing, stored inside a dry space next to fig and grapes..

Orchard —

The bulk of their orchard is made up of espalier fruit trees, shown here as a hedge around the veg garden. They’ve been managed really beautifully so have what I call “posh” shapes; like a proper expected espalier shape. I look at ours and think they’re a little too wayward, though these in contrast have been kept nicely trim. The ones in Kew’s veg garden are similarly nice. They’ve got a few stout lower-than-bush ones, and then half-standard around the inside of an actual hedge; these they call “pleached”, a term I’d never come across before, but is a form where there’s a long bare trunk with square crown.

Images: 1-2. Example of two espalier fruit tree forms (both apples?) around a steel edging; 3. Pleached apple tree used as a windbreak.

Glasshouse + forest areas —

The main glasshouse houses the kitchen, exhibition space and some indoor plants. These were once a series of derelict horticultural buildings making up 320 square metres, and refurbished by local practice HASA Architects. However, there is a mini geodesic wooden framed glasshouse in a forested section of the garden. I imagine that they’re doing propagation elsewhere because this is tiny, but this appeared to act as a cold frame/hardening off before plants go elsewhere, as in here were some small plants, including the cutest aubergines and Nepalese pepper seedlings.

Surrounding this was a wild habitat area with dead/decaying logs where kale was being grown, plus patches for gooseberries (which in my eyes needed a hearty management to prevent undergrowth causing stress) and rhubarb with strawberries. They don’t use the term “forest garden” anywhere that I can see, but it was a less cultivated area with plants that survived well in dappled shade. Over here was also the toilet block, screened out by a curving willow wattle.

Images: 1. Small aubergine plant and Nepalese pepper seeding in the geodesic glasshouse; 2. Sichuan peppercorns on the tree; 3. Patch of rhubarb with (could be alpine rather than "real") strawberry groundcover

Beekeeping.

On entering the veg garden you’re greeted with a sweet tower with a house-shaped solitary bee box on top. I was trying to figure out if the tower was for honeys with a round entrance hole, but it wasn’t possible to get close enough; it could also be a bird box. Around the garden next to paths, I spotted two additional Langstroth hives, though were overgrown or didn’t appear to be active. I liked how they were situated in the forested areas, and particularly for the one in the hedge, it’s clearly not being managed for honey because it’d be difficult to get in. But, even if I wasn’t intervening, I’d still want them in more obvious or accessible spots for any visitors, higher off the ground for the sake of predators, and not in bushes to prevent overgrowth.

Images: 1. Honeybee hive hidden in an overgrown hedge; 2. Honeybee hive in a forested section of the garden; 3. Solitary bee box shaped like a house on top of a birdbox tower amidst the vegetable garden.

Pond.

This was possibly a highlight. The pond was so significant in size that it really felt difficult to remember that I was in a populated part of North London where space is limited (excepting Highgate Cemetery and Hampstead Heath of course). On one side was the view of a house and then a mini house below for ducks, and then on the other was a windbreak of trees. Hidden amongst was the algal green waters, stagnant (but not horribly so) and somewhat disorienting, like, I actually didn’t want to move around as it was hard to ascertain what was ground. The pond was full of reeds and floating aquatic plants, which I don’t know enough about, but I’m pretty sure there was watercress. Flowers including rosebay willowherb and spear thistle were dotted around, delicious for bumblebees.

Images: 1. View of a house in the background, with mini duck house below amongst bulrush reeds and floating plants including watercress; 2. Other side of the pond with grasses and flowering shrubs; 3. Bumblebee on a sow thistle going to seed with 'thistledown' floating away.

Wildflower meadow.

Another impressive section was the wildflower meadow, particularly lovely on this bright warm August day as it was full-to-brimming with insects. The lavender especially was a party for bumblebees of multiple species. It was a large section at the top of the garden close to the glasshouses, with a mown margin and more fruit trees; a place to sit and meditate for sure. Chairs were dotted around for visitors; some folk were chatting, others were drawing. It was early August but already there were signs of seasonal changes, with lavender flowers dropping off and other seedheads turning brown. It was the quintessential meadow perspective.

Images: 1. Wildflower meadow showing grasses, wild carrot, red poppies; 2. Close-up of some wildflowers with lots browing already for seed; 3. Bumblebees harvesting from the lavendar shrubs.

Kitchen + exhibition space.

I lastly came to the indoor kitchen and exhibition space housed within the aforementioned refurbished glasshouses. Polished concrete abounded with ramps to transport you up and down the levels. Grape vines with fruit clusters hung above in a dramatic fashion. Fig trees also featured in the middle. Dotted around were old seed processing equipment next to modern; a wooden threshing chamber next to a hanging net.

The exhibition space showed photos taken for the World Food Programme’s Home-Grown School Meals ongoing project, where they’ve collaborated with 100+ countries to provide “home-grown school feeding” to schoolchildren that helps support local farmers as well as improved nutrition. Here, OmVed also host the Chefs' Manifesto, a community of 700+ chefs from 77 countries who come together to have global conversations around food — while eating food.

I also purchased back issues of Where the Leaves Fall magazine (spread out for honesty shopping), which “considers local and global experiences and knowledge as a pathway to healing our relationship with nature, with culture, with community and with our home, the Earth”, presenting often marginalised voices.

Images: 1. Glasshouse space with polished concrete surfaces and overhanging grape vines; 2. Overhanging grape vines with fruit clusters; 3. World Food Programme exhibit on the Home-Grown School Feeding ongoing project.