A compact, modular and low‑cost hydroponic greenhouse

Plant Molecular Farming (PMF) is emerging as a cost-effective alternative for producing recombinant biopharmaceuticals, yet laboratory-scale cultivation platforms remain limited. We present a compact, modular hydroponic greenhouse designed to support supervised growth of Nicotiana benthamiana, or other plant species, in standard laboratory environments. The system integrates a recirculating hydroponic module, rockwool-based plant support, adjustable LED lighting, and continuous monitoring of key environmental parameters, ensuring reproducible and physiologically suitable growth conditions. Validation across four cultivation batches demonstrated stable temperature (23-25 °C), relative humidity (∼60%), and uniform light distribution, resulting in consistent plant growth and morphology (maximum height: 23 cm, total leaf area: 420 cm², and leaf mass: 489 g). With a low build cost (£781) and scalable, open-source design, this platform provides an accessible solution for early-stage PMF research and upstream process development.