Should I Grow Microgreens in Soil or Hydroponics?

One of the most common questions from new microgreens growers is whether to use soil or a hydroponic growing medium. Both methods work and both produce excellent microgreens, but they have different trade-offs in terms of cost, ease of use, cleanliness, mould risk and flavour. The right choice depends on your goals, your budget and how much mess you are comfortable with in your kitchen or growing space.

Growing in Soil or Coco Coir

Seed-starting mix and coco coir are the most beginner-friendly growing media. They hold moisture well, buffer pH naturally, and provide some physical nutrition to the seedling roots. Coco coir (coconut husk fibre) is lightweight, rehydrates easily from a compressed block and is a renewable resource. Standard seed-starting mix works similarly but is slightly heavier and can contain perlite or vermiculite that adds aeration.

The main advantage of soil or coir is forgiveness: it holds moisture well enough that you can go slightly longer between waterings without the medium drying out completely. It also supports a wider range of seed types — including large-seeded crops like sunflower, peas and wheatgrass — better than thin hydroponic mats. The main disadvantage is messiness: soil or coir ends up on your kitchen counter, in the sink when you harvest, and on the roots when the tray is discarded. Disposing of used medium requires either composting or bin disposal.

Hydroponic Growing Mats

Hydroponic mats — jute fibre mats, hemp grow mats, or purpose-made foam pads — are thin sheets that sit in the bottom of the tray. Seeds are spread on the surface of the mat, which is kept moist by bottom-watering. The roots grow through or on the mat surface and the entire thing can be lifted cleanly when harvesting. This is neater than soil, easier to clean up and produces harvested greens that are free of soil particles at the cut point.

The trade-off is that hydroponic mats require more consistent moisture management — they have much less buffer capacity than soil and can dry out quickly, stressing seedlings. Flavour can be slightly less complex in hydroponic-grown crops (soil microorganisms contribute minor flavour compounds), though for most crops the difference is minimal. Large seeds like sunflower can be more difficult to anchor in hydroponic mats.

Which Is Better for Flavour?

For most varieties — radish, broccoli, peas, kale, mustard — there is no meaningful flavour difference between soil and hydroponic growing. Basil and other aromatic herbs are an exception: many experienced growers find that soil-grown basil and coriander microgreens have slightly richer, more complex fragrance than those grown hydroponically. This is likely related to the presence of soil microbiota and minor mineral variation in the growing medium.

Recommendation for Beginners

Start with coco coir or a quality seed-starting mix. It is more forgiving, works for every common microgreens variety, and is cheap and widely available. Once you are comfortable with the process and want a cleaner, lower-mess setup — particularly if you are growing large quantities or selling microgreens — consider moving to hydroponic mats for small-seeded brassica varieties while keeping soil or coir for large-seeded crops.