Seed Snails: The Revolutionary Method for Starting Seeds

Could seed snails be the answer to that cluttered bench or windowsill full of seedlings?

I've tried them and it’s transformed how I start seeds. It saves an extraordinary amount of space and money, and it makes potting on a doddle. At last, a snail that’s actually good news for the garden!

How to Make a Seed Snail

Seed snails spiral round, just like the shell of a snail, with the seedlings poking out throughout. The first advantage of this method is that it does away with the need for pots, seed trays and plug trays. Instead, all we’re using to get things underway are strips of plastic. Compared with seedlings in a plug tray this is incredibly space-efficient, so this method could really help you to pack in more seedlings during those busy Spring months.

Sheet plastic, for instance reused from old packing materials, is great for making seed snails, but I reckon bubble wrap is even better because its air pockets help to make the roll a bit sturdier. It also insulates the potting mix inside the snail from swings in temperature, which is better for our seedlings’ roots.

Bubble wrap is flexible, retains moisture well, and can be reused time and again. It’s widely used as packaging in deliveries so it’s usually free, and using it to make seed snails is a great way to give it another use before disposing of it. But if you are concerned about microplastics getting absorbed into the seedlings you’re growing, don’t worry, I have a solution – which I’ll show you in a moment.

Okay, so let’s get started. First cut your bubble wrap down into strips. These could be anything from about 3in (7 cm) wide to 6in (15 cm) or more for deeper-rooting seedlings like beans or sweetcorn. And that’s the beauty of these seed snails – you can customise them for what you’re growing. For length, up to about two feet (60 cm) would be ideal.

To give those seedlings something to grow in, I use a standard multi-purpose potting mix which is suitable for seedlings and young plants. This has enough nutrients in it to give seedlings a good start and help them to grow on a bit until we unravel the snail at planting time.

The potting mix needs to be moistened before using it. This step is important because these rolls tend to be a bit deeper than your average plug or seed tray. We need consistent moisture throughout our mix, and this will essentially prime our mix with water If you squeeze a handful of the potting mix there should be just a few drips coming out, which shows it’s fully moistened but not totally sopping.

Lay a strip of bubble wrap out and load it up with potting mix, aiming for a thickness anywhere from half an inch to two inches thick (1-5 cm), depending on what you’re going to be sowing. Smaller seedlings like, say, lettuce or basil will be fine at the lower end of that scale, while for bigger seeds like beans you’ll want something thicker.

Press the potting mix firmly down as you go. This is important because it will help to give good structure to the seed snail so it doesn’t just fall away or wash out when it’s watered. Break up any lumps, and and pack the edges firmly. Make sure the bottom edge – which will become the base of the roll – is especially well compacted to help the roll stand upright and encourage strong, vertical root growth. Leave an inch (2 cm) or so at one end free of potting mix to make it easier to secure it once rolled.

Next, roll up your potting mix-stuffed snail gently but firmly. If a little bit of potting mix falls out, that’s absolutely fine, or if there’s too much at the end, just pull a little away and keep rolling.

Once your snail is all rolled up, secure it with painter’s or masking tape. Alternatively, you could use string or elastic bands, but painter’s tape works brilliantly and easily peels off when it’s time to unravel the roll for planting. If you need to, wipe the plastic dry so the tape can properly stick.

Stand your snail upright, give it a gentle tap on the table to settle the potting mix, and add a little more mix if it’s needed. This compact, sturdy seed snail will encourage long, straight roots and uses minimal potting mix – just enough to do the job.

Making Seed Snails Without Plastic

There are alternatives to plastic. Newspaper might seem like the obvious choice – it can be tossed straight onto the compost heap once you’re done, after all – but roots tend to grow into or stick to paper, and the snails are more likely to rot and fall apart, so I wouldn’t recommend it.

If you just want to keep roots away from the plastic, try lining your bubble wrap with parchment or greaseproof paper. This needs to be twice the height of your bubble wrap so it covers both sides. Lay the bubble wrap along the bottom and carefully fold the paper up and over so both sides of the bubble wrap are covered. And then to secure the grease proof paper ahead of rolling, stick it in place with a few bits of masking tape. This will keep roots physically separated from the plastic, and because the bubble wrap is fully covered, it will last longer for future uses and can easily be rinsed off, dried and stored in a dark, dry place till your next sowing session.

Alternatively, for a completely no-plastic way to make a seed snail, use corrugated cardboard. Cut it to size as described for the bubble wrap method above, then roll it up tightly to help make it easier to roll when it’s filled with potting mix. Unroll it, layer up your potting mix, then roll it into a snail. Keep it rolled up tight using a couple of elastic bands.

This simple step really elevates this seed snail method because we’re keeping those seedlings as natural as possible and avoiding unnecessary plastic from being transferred into the garden. Nice!

Sowing Into a Seed Snail

Once your seed snail’s made, you’re good to sow. Don’t be tempted to sow before rolling up your snails, because seeds are likely to shift about and you may not end up with them at the perfect depth.

For smaller seeds it’s easiest to sow directly onto the surface, dropping seeds every half inch (1 cm) or so, then top up with a thin layer of potting mix to cover them over. Bigger seeds, or where we want to encourage deeper roots, can go into taller rolls. You can dib individual holes to drop in each seed before filling the hole back in.

This method is brilliant for a wide range of seeds, from warm-season favourites like tomatoes, peppers and sweetcorn to staples like leeks, lettuce, and cabbage family crops.

You could sow more than one variety in a roll by using a seed label to mark the start of the next variety, but given that different crops and varieties may germinate and grow at different rates I think it’s just a lot simpler to keep to one variety per roll. They’re so compact, it’s still very space-efficient to keep them separate.

Once planted, mist the surface well, or water larger seeds with a watering can. Until the seedlings poke through, keep the top moist. Regular spraying as needed works perfectly. A propagator lid or a clear bag secured over the top of seed snails really helps retain moisture, especially for smaller seeds, but it’s not essential for larger ones like beans.

Pack your seed snails into a tray to keep them upright. This is possibly the biggest advantage of this method: it’s a lot more efficient on space. Seed snails fit very neatly on an average windowsill. And because seed snails tend to be deeper than your typical seed or plug tray, you’re encouraging a better, deeper-reaching root system, which compensates for the slightly close spacing between the seedlings at this early stage.

Potting On and Planting Your Snail Seedlings

When seedlings are ready, all you have to do is simply unroll the snail and there they are: beautifully spaced, long-rooted young plants that separate easily with minimal disturbance. No wrestling with tangled roots, and no broken stems.

And if seedlings need a bit more time before planting out into their final growing positions, you’ve still got options. For plants that need just a little more compost to grow into, unroll the snail, add a fresh layer of compost over the top, then gently reposition the seedlings if needed and roll it back up. Job done!

For plants that need more room, you could pot them on into larger snail rolls. Gently separate them, then space them out evenly in fresh compost, and roll them up again. You can fit an impressive number of plants into very little space this way.

You might notice that plants grown this way are sometimes a touch smaller than those grown in individual pots, but the difference is small, while the space saving is huge – and they’ll quickly catch up when they’re eventually transplanted. And when it’s time to harden off (acclimatise your seedlings to outdoor conditions) in advance of planting, moving several seed snails is a lot quicker and easier than lugging several trays or pots in and out. That’s a lot of wins for one small roll of soil!

Seed Snail Feeding and Aftercare

Seedlings shouldn’t need fertiliser at first, but if they do start to look a bit hungry (for instance, the leaves are going yellow), pot them on as above or water on a a half-strength liquid fertiliser such as a seaweed feed.

Because there’s less potting mix involved, seed snails do need to be monitored a bit more closely to keep an eye on moisture levels, but once you get into the habit it’s easy. With cold-tolerant crops like onions and cabbages, you could even temporarily sink the rolls into garden soil, letting the roots reach down into the soil for nutrients and water till you’re ready to plant, while freeing up indoor space.

Seed snails really are a game-changing way to start seeds! They’re simple, flexible, space-saving, and incredibly satisfying to use. Whether you’re short on space or potting mix, or just fancy trying something new, they’re definitely worth a go.