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The earlier you sow, the better it eats 🥬 Late winter beats spring

Learning by growingAbout 10 min
The earlier you sow, the better it eats

🥬 "My spring mooli always go hollow."

🥬 "I put a tunnel up and cooked everything inside it."

🥬 "I assumed I should wait until it warmed up."

Hello, I'm Eiko. Eight years of growing vegetables organically and without pesticides, and a teaching licence in science.

It's late winter. It's still cold.

And the people who sow now get the best of it.

The point, up front:

Spring vegetables are better quality the earlier they're sown.

The price is frost protection. Effort traded directly for quality — and the trade is unusually explicit, which is what makes this time of year interesting ☺️

Sowing date changes the crop's character

Diagram: sowing date changes the character

What this diagram says

  • Sowing date changes the character
  • ○ Sown in the deep cold — protection needed (two layers) ／ few pests and diseases ／ the mooli are good quality
  • Sown in spring — no protection needed ／ pests and diseases appear ／ quality drops
  • Effort and quality are traded directly
  • In the cold, neither insects nor fungi are active. There is simply no enemy in the garden

Mooli can be sown in spring, summer or autumn. The spring window is long — from the depths of winter through to mid spring in most places.

And within that same window, the result is completely different depending on when you sow.

Why earlier is better

Simply: in cold weather neither insects nor fungi are active.

Mooli pests start moving once temperatures rise, and so do the fungal pathogens. A garden in the deep cold has no enemy in it.

And a root that grew slowly in the cold is dense. You can feel the difference when the knife goes in, compared with one that grew in a hurry.

What you put in as effort comes out as quality. I like that trade.

The enemy of spring sowing is bolting

Bolting is the plant switching over to making flowers. A stem rises from the centre and everything goes into it.

Once it does:

In other words, they stop being food.

Why spring in particular

Most vegetables work on this rule: a plant that has reached a certain size and is then exposed to cold concludes that it has overwintered, and sets flower buds.

Spring sowing walks straight into that condition. Sow, grow a little, and there's still cold weather to come. From the plant's point of view: "I've got through a winter — time to reproduce."

The answer is entirely in the variety

Choose a variety that resists bolting.

Look for "for spring sowing" or "slow to bolt" on the packet. As with everything else, the answer is on the back.

Get this wrong and there's no recovering, because it isn't a growing problem — it's a variety problem. I once sowed an autumn variety in spring and bolted the entire row. Everything about how I grew them was correct.

Sowing mooli in the cold

Diagram: how to sow in the deep cold

What this diagram says

  • How to sow in the deep cold
  • 1 Depth — to the first joint of your index finger — because the surface swings in temperature
  • 2 In a triangle, one seed each — one per hole, spaced apart ／ × put together, the roots tangle at thinning
  • 3 Cover and firm — seed and soil in contact, so water is carried to it
  • Mooli germinates even when it's a bit dry. After rain you don't need to water

Depth: the first joint of your finger

Sowing in the cold, go slightly deeper than usual — as deep as your index finger goes to the first joint.

Why: the top centimetre swings wildly in temperature. A little further down the day-to-night difference is smaller and steadier, and a seed can get on with things.

A triangle, one seed per hole

For station sowing:

Don't put three seeds in one hole.

They germinate with their roots tangled, and thinning one pulls up the one you wanted. Spaced apart, you simply cut the surplus off with scissors.

Cover, then firm

Once the soil is over the seed, press it down with your palm.

Unglamorous, and it's what makes germination even.

Seed and soil in contact means the soil's moisture reaches the seed. Tipped on loosely, there's a layer of air around the seed and the water never arrives.

Water only when you need to

Counter-intuitively, mooli germinates even in fairly dry soil.

If it rained recently, don't water. This is where mooli differs from spinach and carrots.

Water lightly only if the soil is bone dry and you want them up sooner.

Ventilating the tunnel is the real skill

Diagram: the work starts once the tunnel is up

What this diagram says

  • The work starts once it's up
  • 1 From sowing to germination — sealed. Up in 5–7 days
  • 2 After germination, sunny daytime — ventilate so it doesn't exceed 30 °C
  • 3 Days with a maximum of 20 °C or less — opening it slightly is enough
  • 4 Nights with morning frost — close it at night
  • Let it out by day, hold it in at night ／ if opening and closing is a nuisance, use a pre-vented film
  • Outside at 10 °C, inside a sunny tunnel exceeds 30 °C

Putting it up isn't the job

My first tunnel failure was heat. I put it on and left it, and the inside was like midsummer. Every seedling was finished.

Sealed until germination

Five to seven days and they're up. Until then you don't need to open it — the warmth inside is the point.

Then start ventilating

Three rules:

  1. Don't let it exceed 30 °C inside
  2. On days with a maximum of 20 °C or less, opening the hem here and there is enough
  3. When morning frost is likely, close the hem at night

Day and night are opposites: let it out by day, hold it in at night.

On a clear late-winter day the inside of a film tunnel gets startlingly hot. Outside 10 °C, inside over 30 °C. That's what a greenhouse is.

If the daily opening and closing is unrealistic — and before and after work it rarely lines up — there is film sold with ventilation holes already in it. It holds less heat, and it needs no opening and closing. It prevents scorched seedlings, which makes it the right choice for anyone who can't get to the garden on weekdays. I use both: unvented film on the beds I see daily, vented on the ones I only reach at weekends. Tools can be chosen to fit your life.

Six things to sow now

Diagram: six leaf and root crops for spring sowing

What this diagram says

  • Leaf and root crops you can sow in spring
  • Spring mooli — earlier is better quality. Choose a bolt-resistant variety
  • Spring carrots — easier than summer sowing. Cover thinly
  • Small turnips — no deep digging needed. Good in containers
  • Head lettuce — few pathogens and few insects
  • Spinach — naked seed germinates evenly
  • Mustard greens (komatsuna) — the easiest of all

Mooli

Earlier is better. Choose for bolt resistance.

Carrots

Easier than a summer sowing. The usual carrot failure is drying out, and in spring the soil doesn't dry.

Carrot seed wants light, so the covering is thin — the opposite of mooli. And firm it well.

Small turnips

No deep cultivation needed, so they grow in containers. Same family as mooli, but the season is short enough that bolting is less of a worry. The easiest soil preparation of anything here.

Head lettuce

A spring lettuce sowing is remarkably straightforward, for three reasons:

And lettuce seed goes dormant above about 25 °C — so a cool sowing is simply the sensible one.

Spinach

Spinach seed is protected by a hard case and germinates unevenly. Naked seed — with the case removed — makes a visible difference. If spinach has frustrated you, change only this.

Mustard greens

The hardest crop in the world to fail with. Fast, and cold-tolerant. If you don't know what to sow, sow this and you won't be wrong. Also the best one to grow with children.

To sum up

You don't have to do all of it. Buy one packet of mustard greens. Sow it now and lay fleece over it. That's your first harvest of the year 🥬

Thank you for reading!