When to plant watermelons in Tulsa: 29 April – 8 August

In Tulsa, watermelon: sow for seedlings from 11 March to 11 July; plant into a greenhouse from 8 April to 8 August; plant out into open ground from 29 April to 8 August. For plants and seeds, the places nearby include Garden Deva (garden centre, 2 km) and Southwood Home & Garden (garden centre, 3 km); addresses and opening hours are below.

Watermelon in Tulsa: soil, season and weather

In Tulsa the soil, not frost, sets the date: the last frost is over around 6 March, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 29 April, 54 days later.

Last spring frost	6 March
Top 7 cm of soil at 18 °C	29 April, 54 days after the last frost
Into an unheated greenhouse	8 April – 8 August; April outside: 10.7 °C at night, 21.9 °C by day; card 18–35 °C
First autumn frost	17 November, 202 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	27 June – 6 October
Days left for picking	143
Daylight	12:34 on 1 April, 13:35 on 29 April
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 7 rainy days

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

Watermelon in Tulsa: care after planting

Planted on 29 April: in the first weeks water every 5 days.

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

29 April — 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 Tulsa during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 33.6 °C. Months that stay below 18 °C even by day on average: November (16.4 °C). Nights average below 18 °C in April, May and October, November (6.6–16 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	21.9	10.7	155	11	13:06
May	26.1	16	164	14	14:04
June	31.8	21.5	108	9	14:36
July	33.6	23.6	98	10	14:24
August	32.6	22.8	108	10	13:34
September	29.9	19.7	94	7	12:27
October	23.4	13.1	107	8	11:19
November	16.4	6.6	73	7	10:16

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Tulsa, Lawton is 25 days earlier and Fayetteville 10 days later.

City	Distance	Date	Difference
Oklahoma City	157 km	15 April – 1 August	14 days earlier
Fayetteville	165 km	9 May – 1 August	10 days later
Joplin	168 km	5 May – 23 July	6 days later
Fort Smith	169 km	1 May – 9 August	2 days later
Wichita	209 km	2 May – 21 July	3 days later
Lawton	278 km	4 April – 2 August	25 days earlier

Where to buy watermelon plants and seeds near Tulsa

Buy plants ready to set out from 29 April to 8 August (from 8 April to 8 August for an unheated greenhouse); seed for raising your own is sown from 11 March to 11 July. Within 15 km of Tulsa OpenStreetMap lists 8 garden centres, 2 farm-supply shops, 1 plant nursery, 1 market and 1 farm shop (collected 20 October 2026).

Walmart Garden Center — garden centre
13 km
Southern Agriculture — farm shop
13 km
Garden Deva — garden centre
East 3rd Street South 1326, 74120 Tulsa · 2 km · gardendeva.com
Southwood Home & Garden — garden centre
South Lewis Avenue East 1102, 74104 Tulsa · Wed–Sun 10:00–18:00 · 3 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.

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