When to plant watermelons in Davenport: 17 May – 21 July

In Davenport, watermelon: sow for seedlings from 29 March to 23 June; plant into a greenhouse from 26 April to 21 July; plant out into open ground from 17 May to 21 July. For plants and seeds, the places nearby include Wallaces Garden Center (garden centre, 3 km); addresses and opening hours are below.

Watermelon in Davenport: soil, season and weather

In Davenport the soil, not frost, sets the date: the last frost is over around 20 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 17 May, 27 days later.

Last spring frost	20 April
Top 7 cm of soil at 18 °C	17 May, 27 days after the last frost
Into an unheated greenhouse	26 April – 21 July; April outside: 5.3 °C at night, 16 °C by day; card 18–35 °C
First autumn frost	30 October, 166 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	15 July – 18 September
Days left for picking	107
Daylight	13:29 on 19 April, 14:34 on 17 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 9 rainy days

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

Watermelon in Davenport: care after planting

Planted on 17 May: in the first weeks water every 5 days.

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

17 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 Davenport during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 29.4 °C. Nights average below 18 °C in May (12 °C), September (16.1 °C) and October (9.2 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	22.6	12	112	12	14:30
June	28.6	18.2	93	11	15:10
July	29.4	20	80	11	14:55
August	28.3	19	77	9	13:53
September	25.8	16.1	77	8	12:31
October	18.2	9.2	88	10	11:09

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Davenport, Springfield is 2 days earlier and Rockford 11 days later.

City	Distance	Date	Difference
Cedar Rapids	100 km	20 May – 16 July	3 days later
Peoria	129 km	18 May – 22 July	1 day later
Rockford	149 km	28 May – 19 July	11 days later
Madison	195 km	28 May – 18 July	11 days later
Springfield	212 km	15 May – 23 July	2 days earlier
Chicago	249 km	28 May – 28 July	11 days later

Where to buy watermelon plants and seeds near Davenport

Buy plants ready to set out from 17 May to 21 July (from 26 April to 21 July for an unheated greenhouse); seed for raising your own is sown from 29 March to 23 June. Within 15 km of Davenport OpenStreetMap lists 2 garden centres and 1 market (collected 28 October 2026).

Wallaces Garden Center — garden centre
Northwest Boulevard 6227 · 3 km · wallacesgardencenter.com
Wallace's Garden Center — garden centre
10 km
Freight House Farmers Market — market
5 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