When to plant watermelons in Peoria: 18 May – 22 July

In Peoria, watermelon: sow for seedlings from 30 March to 24 June; plant into a greenhouse from 27 April to 22 July; plant out into open ground from 18 May to 22 July. For plants and seeds, the places nearby include Bottom Line Solutions (garden centre, 12 km) and Ron's Produce (farm shop, 15 km); addresses and opening hours are below.

Watermelon in Peoria: soil, season and weather

In Peoria the soil, not frost, sets the date: the last frost is over around 19 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 18 May, 29 days later.

Last spring frost	19 April
Top 7 cm of soil at 18 °C	18 May, 29 days after the last frost
Into an unheated greenhouse	27 April – 22 July; April outside: 5.9 °C at night, 16.7 °C by day; card 18–35 °C
First autumn frost	31 October, 166 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	16 July – 19 September
Days left for picking	107
Daylight	13:29 on 20 April, 14:32 on 18 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 7 rainy days

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

Watermelon in Peoria: care after planting

Planted on 18 May: in the first weeks water every 5 days.

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

18 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 Peoria during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 29.3 °C. Nights average below 18 °C in May (12.5 °C), September (16.4 °C) and October (9.6 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23	12.5	123	12	14:26
June	28.5	18.3	90	11	15:04
July	29.3	20.1	94	12	14:49
August	28.3	19.1	82	10	13:49
September	25.9	16.4	57	7	12:31
October	18.6	9.6	97	10	11:11

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Peoria, St. Louis is 10 days earlier and Rockford 10 days later.

City	Distance	Date	Difference
Springfield	99 km	15 May – 23 July	3 days earlier
Davenport	129 km	17 May – 21 July	1 day earlier
Rockford	180 km	28 May – 19 July	10 days later
Chicago	211 km	28 May – 28 July	10 days later
Cedar Rapids	224 km	20 May – 16 July	2 days later
St. Louis	235 km	8 May – 26 July	10 days earlier

Where to buy watermelon plants and seeds near Peoria

Buy plants ready to set out from 18 May to 22 July (from 27 April to 22 July for an unheated greenhouse); seed for raising your own is sown from 30 March to 24 June. Within 15 km of Peoria OpenStreetMap lists 3 garden centres, 1 market and 1 farm shop (collected 28 October 2026).

GroUp Gardening — garden centre
14 km
Bottom Line Solutions — garden centre
Cooper Road 25356, 61550 Morton · 12 km · enduraplas.com
Peoria Farmer's Market at Metro Centre — market
Mon–Sat 08:00–12:00; Jan, Feb, Mar, Apr closed · 6 km · shopmetrocentre.com
Ron's Produce — farm shop
North Radnor Road 10213, Peoria · 15 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