Last edited by shiny on 8 Nov 2026. View history
Watermelon
A variety of melon
How to sow watermelon: Direct seed into soil or peat pots (and transplant pots directly into soil after hardening off)
Sun requirement for watermelon: Plant in Full Sun
The watermelon is a species of melon that produces round or oblong fruits with thick skin and sweet, watery flesh. It is a special kind of berry with a hard rind and no internal division, botanically known as a "pepo." The rind is usually dark green with light-green stripes. The flesh can be red or yellow. Like other melons and members of the Cucurbitaceae family, the watermelon grows on sprawling vines.
A plant grows with warmth, not with days. A growing degree day is one day's worth of useful warmth: how many degrees the day's average temperature is above the lowest temperature the crop grows at. Add them up from planting and you know how far along the crop is, whatever the calendar says.
Say that lowest temperature is 10°C. A day averaging 17°C gives 7 growing degree days. A day averaging 8°C gives none, as it is too cold for the crop to grow. That is why the same lettuce takes about 50 days in a summer and 90 in an autumn: it needs the same total warmth either way.
For watermelon, the FAO EcoCrop database gives a lowest growing temperature of 9°C and a shortest growing cycle of 50 days at its best temperature, about 750 growing degree days to a first harvest.
Where you've told us where your garden is, we use this and the weather there to predict when your watermelon will be ready to harvest. We don't use it for how long a plant lives or when it finishes: we go by what members have logged for that.
Only plantings by members who have set their locations are shown.
by erin,
I live in Massachusetts in the US, and just found out that I do, indeed, have space for planting in the giant garden that is apparently shared between the neighborhood. Is it too late to start zucchinis and watermelons? What about sauce [tomato](/crops/toma…
zucchini
watermelons
tomatoes
Nobody has harvested this crop yet.
Sign in or sign up to track your watermelon harvests.Data from the FAO EcoCrop database for Citrullus lanatus (Thunb.) Matsumura & Nakai
| Family / Taxonomy | Magnoliopsida Dilleniidae Violales Cucurbitaceae |
|---|---|
| Life form | herb, vine |
| Life span | annual |
| Habit | prostrate/procumbent/semi-erect |
| Optimal soil depth | deep (>>150 cm) |
| Optimal soil texture | medium |
| Optimal soil fertility | high |
| Optimal soil drainage | well (dry spells) |
| Optimal soil salinity | low (<4 dS/m) |
| Photoperiod | long day (>14 hours) |
Resources outside Growstuff.
morning glory
Photos
View all watermelon seeds