When to plant watermelons in Columbia: 28 March – 20 August

In Columbia, watermelon: sow for seedlings from 7 February to 23 July; plant into a greenhouse from 7 March to 20 August; plant out into open ground from 28 March to 20 August. For plants and seeds, the places nearby include Seven Oaks Plant Shop (garden centre, 13 km); addresses and opening hours are below.

Watermelon in Columbia: soil, season and weather

In Columbia the soil, not frost, sets the date: the last frost is over around 9 March, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 28 March, 19 days later.

Last spring frost	9 March
Top 7 cm of soil at 18 °C	28 March, 19 days after the last frost
Into an unheated greenhouse	7 March – 20 August; March outside: 8.7 °C at night, 20.6 °C by day; card 18–35 °C
First autumn frost	29 November, 246 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	26 May – 18 October
Days left for picking	187
Daylight	11:24 on 28 February, 12:24 on 28 March
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 7 rainy days

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

Watermelon in Columbia: care after planting

Planted on 28 March: in the first weeks water every 5 days.

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

28 March — 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 Columbia during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 33.2 °C. Nights average below 18 °C in March–May and October, November (8.1–16.9 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
March	20.6	8.7	91	10	11:56
April	24.7	12.1	94	8	13:01
May	28.3	16.9	118	11	13:55
June	31.6	20.9	89	12	14:24
July	33.2	23.2	121	16	14:13
August	31.6	22.2	120	14	13:27
September	29.6	19.4	105	9	12:25
October	24.5	13.9	68	7	11:22
November	19	8.1	62	7	10:25

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Columbia, Savannah is 31 days earlier and Asheville 57 days later.

City	Distance	Date	Difference
Charlotte	138 km	13 April – 4 August	16 days later
Greenville	159 km	23 April – 13 August	26 days later
Charleston	170 km	12 March – 10 September	16 days earlier
Savannah	214 km	25 February – 14 September	31 days earlier
Athens (United States)	217 km	17 April – 13 August	20 days later
Asheville	226 km	24 May – 24 July	57 days later

Where to buy watermelon plants and seeds near Columbia

Buy plants ready to set out from 28 March to 20 August (from 7 March to 20 August for an unheated greenhouse); seed for raising your own is sown from 7 February to 23 July. Within 15 km of Columbia OpenStreetMap lists 6 garden centres, 2 farm-supply shops and 3 markets (collected 28 October 2026).

Seven Oaks Plant Shop — garden centre
Saint Andrews Road 4522, 29210 Columbia · 13 km
Farmers Market Xchange — market
Lady Street 912, Columbia · 1 km
Natural Roots — garden centre
1 km
Wilson's Nursery on the market — garden centre
11 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