Growing microgreens without soil is simple: line a shallow tray with damp paper towels, scatter seeds evenly across the surface, keep them covered for two to three days, then move the tray into bright light. Most varieties are ready to cut in 7 to 14 days, with no compost, no potting mess and very little to clean up afterwards.
I started growing microgreens on paper towels because I wanted fresh greens in a flat with no balcony, no compost bag and no patience for soil scattered across the windowsill. The method costs almost nothing, takes about ten minutes to set up, and gives you a dense tray of broccoli or radish shoots in under two weeks. After several seasons of testing trays in my own kitchen, I want to walk you through exactly what works, where people usually go wrong, and which seeds are worth your first attempt.
What growing microgreens without soil actually means
Soil-free microgreens are young seedlings grown on an inert, moisture-holding surface instead of compost, harvested at 7 to 14 days when the first true leaves appear. The seeds carry enough stored energy to reach the cutting stage on water alone, so the growing surface only needs to hold moisture and give the roots something to grip. Paper towels do both jobs for a few cents per tray, which is why they are the easiest entry point for anyone testing microgreens for the first time. You are not skipping a step by leaving out soil, because at this early stage the plant has not yet started drawing meaningful nutrition from a root zone.
What you need for the paper towel method
The shopping list is short and you probably own most of it already. You need a shallow tray or a food container around 20 x 15 cm, two to three sheets of plain paper towel, a spray bottle, and microgreen seeds. Choose unbleached, unscented paper towels and avoid the quilted or ultra-strong types, since those often contain wet-strength resins you do not want against edible shoots. For seeds, start with something fast and forgiving from the microgreens seed range rather than leftover garden packets, because microgreen varieties are sold untreated and at the seeding density this method needs.
How to grow microgreens on paper towels step by step
The whole process breaks down into six steps, and the first tray takes roughly ten minutes of hands-on work spread across two weeks.
- Fold two to three paper towels to fit the base of your tray and wet them thoroughly, then tip out any standing water so they are damp but not dripping.
- Scatter seeds evenly across the surface, aiming for a single dense layer with the seeds almost touching rather than piled on top of each other.
- Cover the tray with a lid or a second damp towel for the first two to three days to trap humidity while the seeds germinate in the dark.
- Once most seeds have sprouted, remove the cover and move the tray to a bright windowsill or under a grow light for 12 to 16 hours a day.
- Mist once or twice daily to keep the towel moist, checking that no water pools in the base of the tray.
- Harvest when the shoots reach 5 to 8 cm, usually after 7 to 14 days, by cutting just above the paper towel with clean scissors.
For a fuller walkthrough of lighting, soaking times and yields across more varieties, my beginner guide to growing microgreens at home covers the details that a single article cannot. University growers describe the same core routine, and Penn State Extension notes that microgreens need little or no fertiliser because they are harvested long before the stored seed energy runs out.
Paper towel vs hydroponic mat vs soil
The paper towel method wins on cost and convenience, but it is not the only soil-free option. Hydroponic mats made from jute, hemp or coconic coir cost a little more and hold moisture more evenly, while soil and coir give the strongest, longest yields for anything you plan to grow past the microgreen stage. The table below shows how the three compare for a home grower.
| Growing surface | Setup cost | Mould risk | Best for |
|---|---|---|---|
| Paper towel | Lowest, a few cents per tray | Moderate if overwatered | Quick tests and small kitchen batches |
| Hydroponic mat (jute or hemp) | Low to medium | Low, good drainage and airflow | Regular weekly harvests |
| Soil or coir | Medium | Low with good airflow | Bigger yields and longer crops |
For most people the honest answer is to start on paper towels to learn the timing, then move to a reusable mat once you are harvesting every week.
The best seeds for soil-free microgreens
The best soil-free microgreens are large, fast-germinating seeds that sprout in three to five days and do not need burying. Broccoli and radish are the classic starting pair, germinating quickly and standing upright on a flat surface. Pea shoots are sweet and forgiving, sunflower shoots grow thick and crunchy after a short soak, and mustard adds a peppery kick in around ten days. Mucilaginous seeds such as cress also work, though their gel coating can look alarming before it settles. As a rule, the chunkier the seed, the happier it is on paper.
How to stop mould before it starts
Mould is the single most common reason a first tray fails, and it almost always traces back to too much water and too little air. White fuzz that looks like cobweb and disappears when misted is usually harmless root hair, while grey or green patches with a musty smell are true mould. Keep the towel moist rather than soggy, never let water collect in the base of the tray, and run a small fan or crack a window so air moves across the surface. The University of Minnesota Extension recommends watering methods that keep leaves and stems dry to avoid disease, which is exactly why bottom-misting and good airflow matter more than any single product. Spacing seeds so they are not piled three deep also gives each shoot room to breathe.
Frequently asked questions
Can you really grow microgreens with just paper towels and water?
Yes. Microgreens carry enough energy inside the seed to reach harvest on water alone, so a damp paper towel is enough to take broccoli, radish or pea shoots all the way to a 5 to 8 cm cut in 7 to 14 days.
Do soil-free microgreens taste different?
No. Flavour comes from the variety, not the growing surface, so radish grown on paper is just as peppery as radish grown in coir. The difference you notice is in yield, as soil and mats tend to produce slightly taller, sturdier shoots.
How often should I water microgreens on paper towels?
Mist once or twice a day to keep the towel damp without leaving standing water. In a dry, heated room you may need a third light misting, while a humid kitchen might need only one.
Why did my microgreens get slimy or mouldy?
That is almost always excess moisture combined with poor airflow. Tip out any pooled water, reduce misting, thin overcrowded seeds, and move air across the tray with a small fan to stop it happening again.
Can I reuse the paper towels after harvest?
No. Once you cut the shoots the towel is matted with spent roots, so compost it and start fresh. If you want a reusable surface, switch to a jute or hemp mat instead.
Start your first soil-free tray
Growing microgreens without soil is the lowest-risk way I know to get a fast, fresh harvest on a windowsill, and a single tray will tell you within two weeks whether you are hooked. When you are ready to pick your first varieties, browse the microgreens seeds we stock for soil-free growing and start with something quick like broccoli or radish.
