🥬 Swiss chard
The same species as beetroot, selected for leaves and stems instead of roots. Cut and it grows back.
🌱 This one is in the reference and the planting calendar, but you cannot sow it in the game yet.
Swiss chard at a glance
Is Swiss chard frost tolerant?
Yes — it is one of the hardier crops. It shrugs off frost down to -6°C and is only killed below -12°C.
What temperature does Swiss chard grow best in?
It grows best between 7 and 26°C. Below 4°C it stops growing altogether, and above 30°C it slows down.
How many days does Swiss chard take to mature?
About 50–65 days. That is a typical figure: it needs roughly 680 °C·d of warmth above 4°C, so a warm season gets it there sooner and a cool one later. The city calendars below give the sow and harvest dates for each place.
Is Swiss chard a cool-season or warm-season crop?
A cool-season crop. It does best in the mild weather of spring and autumn (and through winter where winters are mild), and slows down in summer heat above 30°C.
What the numbers mean
These are the actual parameters this game runs on. Growth is driven by growing degree days: each day contributes max(0, min(mean temp, 30) − 4), and Swiss chard is ready when that total reaches 680. That is why the same seed takes a very different number of days in Dublin and in Guangzhou.
| Base temperature | 4°CBelow this, the plant accumulates no growing degree days at all. |
|---|---|
| Degree days to maturity | 680 °C·dThe heat budget it must accumulate before it is ready to pick. |
| Comfortable range | 7–26°CWhere it grows without stress. |
| Frost damage below | -6°CLeaves start taking frost damage below this low. |
| Killed below | -12°CBelow this it does not come back. |
| Heat stress above | 30°CAbove this the plant slows down and stops setting fruit well. |
| Typical time to harvest | 50–65 days |
| Yield per bed | 8 bunches |
Things worth knowing
- Chard and beetroot are the same species — one bred for its leaves, the other for its root.
- Its stems come in red, yellow, white and pink, which is where the name rainbow chard comes from.
Where and when to sow Swiss chard
Pick your city to see the months when Swiss chard scores well against that city's real climate records: