When to plant watermelons in Gdynia: 7 June – 10 August

In Gdynia, watermelon: sow for seedlings from 19 April to 13 July; plant into a greenhouse from 17 May to 10 August; plant out into open ground from 7 June to 10 August. For plants and seeds, the places nearby include Anemon (garden centre, 2 km) and Róża Melcer (garden centre, 15 km); addresses and opening hours are below.

Watermelon in Gdynia: soil, season and weather

In Gdynia the soil, not frost, sets the date: the last frost is over around 13 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 7 June, 55 days later.

Last spring frost	13 April
Top 7 cm of soil at 18 °C	7 June, 55 days after the last frost
Into an unheated greenhouse	17 May – 10 August; May outside: 7.7 °C at night, 16.1 °C by day; card 18–35 °C
First autumn frost	19 November, 165 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	5 August – 8 October
Days left for picking	106
Daylight	15:44 on 10 May, 17:04 on 7 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 10 rainy days

The same dates in Gdynia hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Gdynia: care after planting

Planted on 7 June: in the first weeks water every 5 days.

Feeding, by the card’s schedule from that day:

7 June — feed: balanced (NPK)

Pests and diseases of watermelon to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Gdynia during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 22.4 °C. Months that stay below 18 °C even by day on average: October (13.1 °C) and November (7.1 °C). Nights average below 18 °C in every month of the season, from 3 °C to 14.7 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	21.1	12.8	64	13	17:13
July	21.7	14.4	111	15	16:45
August	22.4	14.7	73	13	14:58
September	18.6	11.8	51	10	12:47
October	13.1	7.5	68	13	10:36
November	7.1	3	55	11	8:31

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Gdynia, Toruń is 4 days earlier and Gdańsk 8 days later.

City	Distance	Date	Difference
Gdańsk	20 km	15 June – 10 August	8 days later
Kaliningrad	129 km	14 June – 5 August	7 days later
Olsztyn	151 km	9 June – 7 August	2 days later
Bydgoszcz	159 km	6 June – 3 August	1 day earlier
Toruń	168 km	3 June – 3 August	4 days earlier
Poznań	257 km	6 June – 7 August	1 day earlier

Where to buy watermelon plants and seeds near Gdynia

Buy plants ready to set out from 7 June to 10 August (from 17 May to 10 August for an unheated greenhouse); seed for raising your own is sown from 19 April to 13 July. Within 15 km of Gdynia OpenStreetMap lists 9 garden centres, 1 farm-supply shop, 10 markets and 1 farm shop (collected 28 October 2026).

Róża Melcer — garden centre
Kazimierska 100, 84-240 Reda · 15 km
Anemon — garden centre
Mon–Fri 10:00–17:00; Sat 10:00–13:00 · 2 km
Sklep rolniczy Patryk — farm supply
Mon–Fri 08:00–16:00; Sat 08:00–13:00 · 15 km
Sopocki Rynek — market
Polna 8-10, 81-745 Sopot · "W sobotę bez konkretnych godzin" · 10 km

Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

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