When to plant tomatoes in Topeka: 16 April – 9 July

In Topeka, tomato: sow for seedlings from 2 February to 18 May; plant into a greenhouse from 26 March to 9 July; plant out into open ground from 16 April to 9 July. For plants and seeds, the places nearby include LDI - Topeka (farm supply, 7 km) and Lang Diesel, Inc. (farm supply, 7 km); addresses and opening hours are below.

Tomato in Topeka: soil, season and weather

In Topeka frost, not soil, sets the date: the top 7 cm of soil warms to 15 °C — the minimum on the tomato card — around 15 April, 6 days after the last frost on 9 April, so planting waits only for the week after that frost.

Last spring frost	9 April
Top 7 cm of soil at 15 °C	15 April, 6 days after the last frost
Into an unheated greenhouse	26 March – 9 July; March outside: 3.5 °C at night, 15.3 °C by day; card 16–27 °C
First autumn frost	29 October, 196 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	25 June – 17 September
Days left for picking	126
Daylight	11:03 on 23 February, 13:15 on 16 April
Watering outdoors when fruiting (card)	every 3 days; the driest month, October, has 8 rainy days

Tomato in Topeka: care after planting

Planted on 16 April: in the first weeks water every 4 days.

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

16 April — feed: balanced (NPK)
14 May — feed: nitrogen

Pests and diseases of tomato 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 tomato season

Days average above the tomato card's 16–27 °C in June–September (28–31.8 °C). Nights average below 16 °C in April (7.9 °C), May (13.8 °C) and October (10.4 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	20	7.9	105	10	13:12
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

Tomato in nearby cities

Around Topeka, Joplin is 5 days earlier and Grand Island 14 days later.

City	Distance	Date	Difference
Kansas City	97 km	18 April – 12 July	2 days later
Wichita	207 km	13 April – 10 July	3 days earlier
Lincoln	215 km	23 April – 8 July	7 days later
Joplin	241 km	11 April – 12 July	5 days earlier
Omaha	249 km	26 April – 6 July	10 days later
Grand Island	309 km	30 April – 7 July	14 days later

Where to buy tomato plants and seeds near Topeka

Buy plants ready to set out from 16 April to 9 July (from 26 March to 9 July for an unheated greenhouse); seed for raising your own is sown from 2 February to 18 May. Within 15 km of Topeka OpenStreetMap lists 2 farm-supply shops, 4 markets and 1 farm shop (collected 28 October 2026).

LDI - Topeka — farm supply
Mon–Fri 08:00–17:00; Sat 08:00–12:00 · 7 km · ldi.us
Lang Diesel, Inc. — farm supply
Northwest US 24 Highway 1200, 66608 Topeka · 7 km · langdieselinc.com
Breadbasket Farmers Market — market
Southwest Wanamaker Road 1901, 66614 Topeka · Apr Sat[1]–Nov Sat[3] Sat 07:30–13:00 · 6 km · breadbasketfarmersmarket.com
Downtown Topeka Farmers Market — market
Apr Sat[1]–Nov Sat[2] Sat 07:30–12:00 · 3 km · topekafarmersmarket.com

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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