When to plant watermelons in Olomouc: 3 June – 28 July

In Olomouc, watermelon: sow for seedlings from 15 April to 30 June; plant into a greenhouse from 13 May to 28 July; plant out into open ground from 3 June to 28 July. For plants and seeds, the places nearby include MJM agro (farm supply, 2 km) and Okrasná školka Droždín (garden centre, 7 km); addresses and opening hours are below.

Watermelon in Olomouc: soil, season and weather

In Olomouc the soil, not frost, sets the date: the last frost is over around 21 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 3 June, 43 days later.

Last spring frost	21 April
Top 7 cm of soil at 18 °C	3 June, 43 days after the last frost
Into an unheated greenhouse	13 May – 28 July; May outside: 8.8 °C at night, 19.3 °C by day; card 18–35 °C
First autumn frost	6 November, 156 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	1 August – 25 September
Days left for picking	97
Daylight	14:54 on 6 May, 16:03 on 3 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 9 rainy days

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

Watermelon in Olomouc: care after planting

Planted on 3 June: in the first weeks water every 5 days.

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

3 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 Olomouc during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 26.3 °C. Months that stay below 18 °C even by day on average: October (15 °C) and November (8.2 °C). Nights average below 18 °C in every month of the season, from 1.9 °C to 15.3 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	25	13.9	80	12	16:16
July	26.1	15.2	76	12	15:54
August	26.3	15.3	85	10	14:29
September	21.2	11.2	93	10	12:40
October	15	6.6	60	10	10:51
November	8.2	1.9	53	9	9:07

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Olomouc, Opole is 1 day earlier and Ostrava 5 days later.

City	Distance	Date	Difference
Zlín	51 km	6 June – 28 July	3 days later
Brno	63 km	6 June – 28 July	3 days later
Ostrava	77 km	8 June – 31 July	5 days later
Pardubice	117 km	5 June – 1 August	2 days later
Hradec Králové	123 km	7 June – 2 August	4 days later
Opole	130 km	2 June – 9 August	1 day earlier

Where to buy watermelon plants and seeds near Olomouc

Buy plants ready to set out from 3 June to 28 July (from 13 May to 28 July for an unheated greenhouse); seed for raising your own is sown from 15 April to 30 June. Within 15 km of Olomouc OpenStreetMap lists 5 garden centres, 1 farm-supply shop, 1 plant nursery and 1 market (collected 28 October 2026).

HECHT - specialista na zahradu — garden centre
Sebastiniho 579, 79607 Prostějov · Mon–Sun 08:00–20:00 · 15 km · cz.hecht.cz
Okrasná školka Droždín — garden centre
Horní Úlehla 324/32, 77900 Olomouc - Droždín · 7 km · drozdin.cz
MJM agro — farm supply
Mon–Fri 07:30–17:00, Sat 08:00–12:00 · 2 km
Tržnice — market
Mon–Sun, public holidays 00:00–00:00 · 0 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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