Driving technology forwards to meet future challenges
Four strands of work, carried out on our own site and with university and industry partners: the structure a crop is grown under, the medium it is raised in, the systems that monitor it, and growing leafy crops without soil at all.
Greenhouse design and climate control
Lettuce and its relatives are normally grown outdoors, because a conventional greenhouse costs light and adds heat — an unworkable combination in a British summer. Two projects have tested a structure and a climate system designed around that problem.
Exploring a new type of greenhouse
- Innovate UK10054274 — Farming Innovation Programme, Research Starter Round 2
- RanMarch to September 2023
- Our roleProject lead
- PartnerThe University of Nottingham
A first look at a greenhouse built to transmit more light and hold a better internal climate than glass. Two ideas carried through to the structure that was later built: ETFE cladding, which is strong, durable, easily fabricated and transmits more light than glass; and forced-air ventilation in place of roof vents, keeping internal conditions near ambient. A third — an air-inflated structure, to remove most of the steel above the crop — was explored here but not taken into the built version.
Of note ETFE transmits UVB, which glass blocks. For a propagator that matters: UVB is part of what makes a plant tough enough to leave the glasshouse and survive the field.
Protected Cultivation of Horticultural Crops: Setting a New Standard
- Innovate UK10054907 — Farming Innovation Programme, Feasibility Round 2
- RanMarch 2023 to March 2025
- Our roleProject lead
- PartnersThe University of Hull, Durham University, the University of Nottingham, and Crop Health and Protection
Whereas the Research Starter asked whether the idea held up, this project built it and measured it. Ventilation air is aimed precisely at the airspace the crop occupies rather than the whole volume of the house, so it does not pick up solar gain on the way; because the treated volume is small, dehumidification and evaporative cooling become affordable where they would not otherwise be. Heating, cooling and dehumidification are driven by a thermochemical network whose main input is low-grade heat — waste industrial heat or renewables — with the modest electrical demand met by on-site photovoltaics. Desiccant dehumidification and evaporative cooling proved more cost-effective than DX refrigerative systems, even at commercial scale. That makes them viable technology for future greenhouses, not just for a demonstration.
Of note The greenhouse constructed in this project is now used for further trial work, including both future propagation systems for Ellepots and peat-free propagation, and for the hydroponic lettuce trials described below.
Peat-free production
We expect to be growing entirely in peat-free substrates by 2030. The default replacements — coir, woodfibre, bark, green compost — are largely imported or committed elsewhere, so the question is what else a propagation medium can be built from, and whether a young plant will root into it.
Peat-Free Futures
- Innovate UK10180946 — Farming Innovation Programme, Feasibility Round 4
- RunsOctober 2026 to September 2028
- Our roleProject lead
- PartnersThe University of York and the Biorenewables Development Centre
Developing sustainable growing media for horticulture in Yorkshire, with an emphasis on locally-sourced feedstocks, incorporation of biochar into the medium, and a low-carbon, sustainable business model.
Proving this concept within the boundaries of Yorkshire will show that growing media production can be sustained by a regional rural economy anywhere in the UK, or in the wider world.
Of note Replacing peat is a supply chain question as much as an agronomic one. Our own propagation uses about 14,000 cubic metres of growing media a year; professional horticulture across the UK uses around a million cubic metres. Just over half of the raw material employed in these mixes is still peat.
Ellepot media trials
- CropsLettuce, celery, herbs, leeks, Miscanthus
- Propagation and field trials2021 — ongoing
- System28 mm Ellepot in a 216-cell Proptek Airtray
- Shown atBLSA open days, the Peat-Free Pathway conference, and in customer field trials
A continuing programme comparing peat-free growing media against a peat control, in our own glass and then in the customer's field. The peat-free mixes combine coir, woodfibre and bark, each with the fertiliser, wetting agent and microbial inoculation chosen to suit the blend. Running propagation and field trials together is what makes the results usable: a plug can look well in the tray and still fail to establish.
Of note An Ellepot is wrapped in fine biodegradable paper rather than held in a plastic cell, so roots grow out through the wall instead of circling it — which is what lets a peat-free mix hold together well enough to plant.
Greenhouse automation
A propagation house is one of the few places in horticulture where the whole crop is within reach of a machine. That makes it a sensible place to work out what monitoring and automation can actually do.
CropMAP — crop lifecycle monitoring and automation platform
- Innovate UK10073166 — Farming Futures: automation and robotics
- RunsMarch 2024 to February 2027
- Our rolePartner
- LeadValefresco Limited
- PartnersSaturn Bioponics, Eiratech Robotics UK, and the University of Warwick
A platform to monitor a crop across its whole lifecycle and automate the decisions that follow. The consortium is deliberately end-to-end — a commercial grower, a growing-systems company, a robotics company, a propagator and a university — so that what is built has to work in a real nursery rather than a laboratory. Crystal Heart's contribution is at the propagation end: producing plugs for the growing trials, and assessing where robotics are genuinely ready for commercial use.
Of note Three years is a long run for a project in this field — long enough to follow the same crop decisions through several seasons rather than a single one.
Hydroponic lettuce and leafy crops
Crystal Heart grew hydroponic lettuce commercially for UK supermarkets between 2009 and 2014, so this is a return to ground we have farmed before rather than a new departure.
Current work is on a nutrient film technique system, housed in the greenhouse built under Feasibility Round 2. This structure delivers high light intensity, rich in UVB spectrum, and a climate finely controlled for temperature and humidity.
Of note Whereas in 2014 we grew a Salatrio 'living lettuce' in the UK growing season, current research is focussed on crunchy, ready-to-eat teen leaf varieties grown pesticide-free year round.
Exploring a new type of greenhouse (10054274), Protected Cultivation of Horticultural Crops (10054907) and Peat-Free Futures (10180946) are co-funded by Innovate UK, part of UK Research and Innovation, under Defra's Farming Innovation Programme and the UKRI Transforming Food Production challenge. CropMAP (10073166) is funded under Farming Futures: automation and robotics.
Research partners
We host trials, bring propagation expertise to consortia, and are interested in work that touches growing media, propagation systems, protected cropping or automation.