When to plant watermelons in Topeka: 6 May – 20 July

In Topeka, watermelon: sow for seedlings from 18 March to 22 June; plant into a greenhouse from 15 April to 20 July; plant out into open ground from 6 May to 20 July. For plants and seeds, the places nearby include Murphy Tractor & Equipment (farm shop, 6 km); addresses and opening hours are below.

Watermelon in Topeka: soil, season and weather

In Topeka the soil, not frost, sets the date: the last frost is over around 9 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 6 May, 27 days later.

Last spring frost	9 April
Top 7 cm of soil at 18 °C	6 May, 27 days after the last frost
Into an unheated greenhouse	15 April – 20 July; April outside: 7.9 °C at night, 20 °C by day; card 18–35 °C
First autumn frost	29 October, 176 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	4 July – 17 September
Days left for picking	117
Daylight	12:55 on 8 April, 14:00 on 6 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 8 rainy days

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

Watermelon in Topeka: care after planting

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

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

6 May — 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 Topeka during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 31.8 °C. Nights average below 18 °C in May (13.8 °C), September (17.8 °C) and October (10.4 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	24.5	13.8	168	14	14:18
June	30.8	20.1	93	10	14:54
July	31.8	21.8	122	10	14:39
August	30.7	20.7	100	10	13:43
September	28	17.8	83	8	12:29
October	20.9	10.4	73	8	11:14

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Topeka, Wichita is 4 days earlier and Grand Island 12 days later.

City	Distance	Date	Difference
Kansas City	97 km	7 May – 23 July	1 day later
Wichita	207 km	2 May – 21 July	4 days earlier
Lincoln	215 km	11 May – 19 July	5 days later
Joplin	241 km	5 May – 23 July	1 day earlier
Omaha	249 km	17 May – 17 July	11 days later
Grand Island	309 km	18 May – 18 July	12 days later

Where to buy watermelon plants and seeds near Topeka

Buy plants ready to set out from 6 May to 20 July (from 15 April to 20 July for an unheated greenhouse); seed for raising your own is sown from 18 March to 22 June. Within 15 km of Topeka OpenStreetMap lists 2 farm-supply shops, 4 markets and 1 farm shop (collected 28 October 2026).

Downtown Topeka Farmers Market — market
Apr Sat[1]–Nov Sat[2] Sat 07:30–12:00 · 3 km · topekafarmersmarket.com
Hi-Crest Market — market
Southeast Golf Park Boulevard 455, 66605 Topeka · Sat[2] 09:00–11:00 · 3 km
Murphy Tractor & Equipment — farm shop
Northwest Gage Boulevard 1621, 66618 Topeka · 6 km
Farmers Market — market
2 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