🥒 Zucchini
The famously generous summer star — one plant feeds a family.
Zucchini at a glance
Is Zucchini frost tolerant?
No. Cold hurts it even above freezing: damage starts at 2°C and it is killed below 0°C. Sow or plant it out only after your last frost.
What temperature does Zucchini grow best in?
It grows best between 16 and 30°C. Below 10°C it stops growing altogether, and above 35°C it slows down.
How many days does Zucchini take to mature?
About 45–60 days. That is a typical figure: it needs roughly 650 °C·d of warmth above 10°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 Zucchini a cool-season or warm-season crop?
A warm-season crop. It needs warm days and nights, so it goes in after the last frost, once temperatures are reliably above 16°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, 33) − 10), and Zucchini is ready when that total reaches 650. That is why the same seed takes a very different number of days in Dublin and in Guangzhou.
| Base temperature | 10°CBelow this, the plant accumulates no growing degree days at all. |
|---|---|
| Degree days to maturity | 650 °C·dThe heat budget it must accumulate before it is ready to pick. |
| Comfortable range | 16–30°CWhere it grows without stress. |
| Frost damage below | 2°CLeaves start taking frost damage below this low. |
| Killed below | 0°CBelow this it does not come back. |
| Heat stress above | 35°CAbove this the plant slows down and stops setting fruit well. |
| Typical time to harvest | 45–60 days |
| Yield per bed | 8 zucchinis |
Things worth knowing
- Zucchini grows 2–3 cm a day; gardeners joke about "leaving for a week, coming home to baseball bats".
- The big yellow blossoms are edible too — fried squash blossoms are an Italian classic.
Where and when to sow Zucchini
Pick your city to see the months when Zucchini scores well against that city's real climate records: