# Onions from sets: how we grow them and why they leave the field first

Onions from sets open our onion season. How we plant them, when we harvest, which varieties we grow and why they let us supply onions all year round.

Onions from sets are planted as small bulbs instead of being sown from seed. They grow faster and leave the field in early summer, several weeks ahead of spring-sown onions. Here in Żuławy they open our onion season and close the gap between the old crop and the new one. In this post we show how we grow them, which varieties we plant, and what that means for a buyer who needs onions all year round.

## How onions from sets differ from direct-sown onions

The difference lies in the starting point. Direct-sown onions begin from seed in spring, so the plant first has to build a root system and leaves before it starts putting weight into the bulb. A set starts from a ready-made small bulb, which means it starts with a reserve of energy. It moves into growth faster, closes its cycle earlier and ripens earlier.

That translates directly into timing. Our direct-sown onions come off the field in the second half of August and in September, because the maritime climate of Żuławy stretches the growing season. Onions from sets can be ready as early as the turn of July and August, and our first batches come in even sooner. Those few weeks of lead time count for a great deal in the vegetable trade.

| Feature | Onions from sets | Direct-sown onions |
| --- | --- | --- |
| Starting material | small bulb (set) | seed |
| Start of growth | fast, with a reserve of energy | slower, from scratch |
| Our harvest window | from early summer | second half of August and September |
| Role in the season | opens the season, closes the gap after the old crop | backbone of the crop and stock for storage |
| Our varieties | Takmark, Comae, Kristine, Medusa, Bonus | Hybelle, Hysinger, Hyfive, Nation, Revelation, Bingo |

## How we grow sets on a Żuławy field

Onions cover about 250 hectares on our farm and they are the crop we are proudest of. Sets are the earliest part of that. We plant them early, as soon as the soil lets us into the field, because every day gained at the start pays back later with an earlier harvest. We plant on ridges, guided by Trimble GPS with RTK correction, so the rows hold their geometry and later passes do not damage the plants.

The Żuławy silt soils give sets exactly what they need: plenty of humus, good structure and fertility close to the polders in the Netherlands. Onions leave the soil profile open all season, so weeds have a free run. That is why we use the Ecorobotix ARA spot sprayer, which recognises weeds with cameras and AI and cuts chemical doses by around 70 percent. We break down the whole growing year, from field preparation to harvest, in our guide to [how we grow onions in Żuławy](/blog/cebula-z-zulaw-jak-uprawiamy).

{% callout tone="info" %}
An earlier harvest does not mean cutting corners. Sets go through the same regime as the rest of our onions: Integrated Crop Production, a growing technology free of pesticide residues, and testing of every batch for residues, heavy metals and substances harmful to health.
{% /callout %}

## The onion set varieties we rely on

We choose varieties for two things: ripening time and how well the onion handles post-harvest processing. We usually rely on Takmark, Comae, Kristine, Medusa and Bonus. Among red sets we grow Red Baron and Ruby Star, because they colour strongly and keep the firmness that packhouses expect.

Sets are not the crop for the longest storage. Their job is to reach the market quickly and secure supply at the point when the old crop is running out and the new one is still in the field. Onions for long storage we build on direct-sown varieties, which we describe in our post on the [yellow onion varieties Hybelle and Hysinger](/blog/odmiany-cebuli-zoltej-hybelle-hysinger).

## Harvest and the road to the buyer

Harvesting sets is every bit as serious as harvesting direct-sown onions. A Grimme WV 180 windrower lifts the onions and lays them into windrows to dry, and the harvest itself is done by a self-propelled AVR Puma 3 combine, a 4-row machine with 469 hp and an 8-tonne tank. We go in on dry days, because harvesting in the wet is a straight road to rot. We set out the full calendar of work in our post on the [onion harvest season](/blog/sezon-zbiorow-cebuli).

After harvest the onions go for cleaning and drying for 2 to 4 days, to close the neck and remove excess moisture. Then they move to the DOWNS CropVision optical sorter, where cameras and AI inspect every single bulb in 360 degrees and reject stones, clods of soil and defective bulbs. The line handles up to 100 tonnes per hour, so the early crop does not sit in a queue and reaches the buyer quickly.

## Why sets let us supply onions all year round

This is the main reason we grow sets. Our season falls into three overlapping stages: first onions from sets from early summer, then spring-sown onions from the second half of August, and from autumn onwards the crop released from our own storage of about 13,000 tonnes. As a result, our buyers never hit a window in which onions are unavailable.

| Period | Where the onions come from |
| --- | --- |
| Early summer | Onions from sets, straight from the field |
| Late summer and autumn | Spring-sown onions, straight from the field |
| Autumn, winter and spring | Storage of about 13,000 tonnes, sorted as we go |

Storage closes that chain and lets us steer sales over time instead of selling everything off right after harvest. We explain the technical side in our post on [onion storage](/blog/przechowywanie-cebuli).

## Frequently asked questions

### How do onions from sets differ from direct-sown onions?
We plant sets as small bulbs rather than sowing seed. They start faster, because they begin with a ready reserve of energy, and they ripen several weeks earlier than spring-sown onions.

### When do you harvest onions from sets?
From early summer. The first batches come off the field well before our direct-sown onions, which usually wait until the second half of August and September.

### Which onion set varieties do you grow?
We usually rely on Takmark, Comae, Kristine, Medusa and Bonus. Among red sets we grow Red Baron and Ruby Star.

### Are onions from sets suitable for long storage?
Their strength is the early harvest date, not the longest shelf life. For long storage we use direct-sown onions, which go into our storage facility of about 13,000 tonnes.

### In what form do you deliver onions from sets?
We grade and pack to order: loose, big bags, 15 kg and 10 kg sacks and smaller. Every batch goes through the optical sorter and quality control.

### How much do onions from sets cost?
We calculate the price on current market rates, because the onion market moves through the season. Write to us and we will prepare a quote for your specific order.

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Need early onions before the direct-sown season starts? See our [offer of onions from sets](/oferta/cebula-z-dymki) or write to us through the [contact page](/kontakt). Our full onion range is in the [onion offer](/oferta/cebula).