Organic onion and leek seed collection

Regular price $33.00
Regular price Sale price $33.00
$11.00 × 3 with no fees

This box brings together 6 varieties of organic onions and leeks, one per packet. Their cycle is long: sown as early as February, the onions are harvested in August, while the leeks stay in the ground until March.

Ref. 02e9f71e-e555-426e-929b-680c0e9ca8a9·Vegetable seeds
Assortment : Onion and leek 6
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The summary

  • What you receive: a box set of organic onion and leek seed packets, one variety per packet.
  • The varieties: Stuttgarter Riesen, Lunga di Firenze and white spring onions, and De Carentan 3 leek.
  • When to sow: February to April, in a seedbed.
  • Depth and germination: 1 cm, then 5 to 7 days at 15 to 20 °C.
  • What comes next: transplanting the leek into deep holes, once it is pencil-thick.
  • Seed lifespan: 2 years on average, so sow these before your other packets.

Set of 6 heritage alliums, to sow from February for a harvest through to March

Onions and leeks keep the kitchen supplied for months: onions store well after a single harvest, and leeks can be lifted from the garden all winter. The set includes, among others, the yellow onion Stuttgarter Riesen, the elongated red onion Lunga di Firenze, a white spring onion and the winter leek De Carentan 3, species that are slow to take from seedling to plate and whose seeds keep less well than others.

🧅 Two vegetables, two approaches

Onions are harvested in a single go, at the end of summer, when the foliage dries and flops over of its own accord. After harvesting, a few days of drying in the sun followed by dry storage matter as much as the variety for how long they keep. Leeks follow the opposite logic and stay in the ground all winter, where you pull them as and when you need them, even under snow. These two calendars complement each other, so that an assortment gives you alliums almost all year round without ever harvesting everything on the same day.

Stuttgarter Riesen

Flat yellow onion, early and a good keeper, the benchmark variety for a spring sowing.

De Carentan 3

Stocky winter leek with a thick shaft, very frost-hardy, harvested from October to March.

Seedlings or bulbils

Growing from seed costs less per kilo harvested and opens up varieties that are unobtainable as bulbils.

Dressing the plants

Trimming leaves and roots by a third when transplanting leeks limits evaporation.

⚫ The finest seedling

Allium seeds are small, black and angular, and sowing them mainly calls for steady moisture. Sow at a depth of 1 cm, in a tray or nursery bed, in a fine grow medium kept constantly moist: germination takes about a week at 15 to 20 °C, nearly 2 weeks in soil at 10 °C, and happens in a loop, the young shoot emerging folded in two before straightening up. This phase is the most fragile, because surface drying blocks germination. Once past this stage, the crop asks for little more than clean soil, as these narrow-leaved plants cope poorly with competition from weeds.

Seeds to be sown within 2 years

Onion and leek seeds keep their ability to germinate for 2 years on average, whereas a tomato seed lasts 4 to 6, and a packet that has taken on moisture ages even faster. Sow this kit ahead of the others in your collection, note the opening date on each packet, and sow a little more thickly in the second year.

Individual plugs for transplanting without damage

These seedlings are grown close together and then pricked out, which calls for a uniform tray that is easy to release. The 24-cube tray gives individual plugs that you can lift out without breaking the root, and the hand seeder places these tiny seeds one at a time rather than in a clump. This way you transplant each leek at pencil thickness, plug included, without having to untangle a crowded seedling by hand.

🗺️ A year in the field

Allow plenty of room for these two vegetables. Leeks are sown from February to April, transplanted in June when the seedling reaches the thickness of a pencil, and harvested from October to March, which means nearly a year of ground occupied by the same crop. Onions are sown from February to April, transplanted in May and harvested in August. The growing calendar places these windows in the year, and you will be well advised to fix them before laying out your beds, because these two crops tie up the space for longer than most others.

🕳️ Transplanting into planting pockets

Leeks are transplanted in a way of their own, which often puzzles people at first. You make a 10 cm hole with a dibber, slip the seedling in without filling the hole back in, then simply pour in water: the soil falls back by itself around the roots and lets the shaft develop away from the light, which produces the white part you are after. The deeper the hole, the longer the white. Space them 15 cm apart along the row, and earth up once during the growing period if you want to gain a few more centimetres.

🧄 Seeds in the second year

If you want to produce your own seed, you need to allow two seasons: onion and leek are biennials and only flower in the spring after they are planted. Their large umbels are pollinated by insects, so two onion varieties will cross with each other, as will two leek varieties, whereas an onion will not cross with a leek. Once harvested, the seeds are best kept in an airtight jar in the freezer, which noticeably extends their shelf life. The article on germination failures reviews the causes of poor emergence.

Technical specifications

The essentials

What you sow
Organic onion and leek seedsOne variety per paper herb sachet, labelled with its name.
The varieties in the kit
Onions Stuttgarter Riesen, Lunga di Firenze and white spring onion, De Carentan 3 leek6 distinct varieties in total, all open-pollinated.
Sowing period
February to April, in a nurseryWindow for mainland France, to be adjusted depending on the region.
Seedling depth
1 cmEach sachet states the exact value of its variety.
Germination temperature
15 à 20 °CGrow medium temperature, not room temperature.
Germination time
5 to 7 daysBetween 15 and 20 °C; nearly 2 weeks in soil at 10 °C.

To budget for separately

A dibber
10 cm hole left unfilledThe buried part of the stem forms the white of the leek.
Fast-growing seedling
Within 2 yearsThese seeds lose viability quickly: sow them before the other packets.

In the box

  • 1 kit of organic onion and leek seeds, one variety per grass-paper sachet
  • 1 label with common name and Latin name on each sachet

Variety names and packaging: ZenGreens box set, official photo recorded on 07/10/2026. Germination times by temperature: OSU Extension chart (Oregon). Storage and seed production: DIYseeds onion and leek sheets.

Estimate your
delivery time

The kit, being light, is dispatched on its own or with the rest of your order. Exact shipping costs and final delivery times are displayed at checkout once your address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

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