When to plant watermelons in Brno: 6 June – 28 July

In Brno, watermelon: sow for seedlings from 18 April to 30 June; plant into a greenhouse from 16 May to 28 July; plant out into open ground from 6 June to 28 July. For plants and seeds, the places nearby include Poctivé potraviny (farm shop, 3 km); addresses and opening hours are below.

Watermelon in Brno: soil, season and weather

In Brno the soil, not frost, sets the date: the last frost is over around 24 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 6 June, 43 days later.

Last spring frost	24 April
Top 7 cm of soil at 18 °C	6 June, 43 days after the last frost
Into an unheated greenhouse	16 May – 28 July; May outside: 8.6 °C at night, 18.5 °C by day; card 18–35 °C
First autumn frost	6 November, 153 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	4 August – 25 September
Days left for picking	94
Daylight	15:00 on 9 May, 16:04 on 6 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 9 rainy days

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

Watermelon in Brno: care after planting

Planted on 6 June: in the first weeks water every 5 days.

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

6 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 Brno during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 25.5 °C. Months that stay below 18 °C even by day on average: October (14.3 °C) and November (7.4 °C). Nights average below 18 °C in every month of the season, from 1.7 °C to 15 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	24.2	13.6	71	11	16:12
July	25.5	14.9	69	11	15:51
August	25.5	15	70	9	14:27
September	20.4	11	83	10	12:39
October	14.3	6.4	44	9	10:52
November	7.4	1.7	45	9	9:10

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Brno, Bratislava is 6 days earlier and Vienna 2 days later.

City	Distance	Date	Difference
Olomouc	63 km	3 June – 28 July	3 days earlier
Zlín	77 km	6 June – 28 July	same day
Pardubice	111 km	5 June – 1 August	1 day earlier
Vienna	111 km	8 June – 3 August	2 days later
Bratislava	122 km	31 May – 7 August	6 days earlier
Hradec Králové	126 km	7 June – 2 August	1 day later

Where to buy watermelon plants and seeds near Brno

Buy plants ready to set out from 6 June to 28 July (from 16 May to 28 July for an unheated greenhouse); seed for raising your own is sown from 18 April to 30 June. Within 15 km of Brno OpenStreetMap lists 15 garden centres, 3 farm-supply shops, 1 plant nursery, 6 markets and 7 farm shops (collected 28 October 2026).

Poctivé potraviny — farm shop
Mon–Fri 08:30–18:00 · 3 km
Agro Tuřany Zahradní centrum — garden centre
5 km · agro-turany.cz
Storge — garden centre
6 km
Zahradnictví a rybárna Jura — garden centre
6 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.

Questions