When to plant watermelons in Hagerstown: 23 May – 2 August

In Hagerstown, watermelon: sow for seedlings from 4 April to 5 July; plant into a greenhouse from 2 May to 2 August; plant out into open ground from 23 May to 2 August.

Watermelon in Hagerstown: soil, season and weather

In Hagerstown the soil, not frost, sets the date: the last frost is over around 4 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 23 May, 49 days later.

Last spring frost	4 April
Top 7 cm of soil at 18 °C	23 May, 49 days after the last frost
Into an unheated greenhouse	2 May – 2 August; May outside: 12 °C at night, 23 °C by day; card 18–35 °C
First autumn frost	11 November, 172 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	21 July – 30 September
Days left for picking	113
Daylight	13:38 on 25 April, 14:34 on 23 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 7 rainy days

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

Watermelon in Hagerstown: care after planting

Planted on 23 May: in the first weeks water every 5 days.

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

23 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 Hagerstown during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 31.8 °C. Months that stay below 18 °C even by day on average: November (12.7 °C). Nights average below 18 °C in May, June and September–November (3.4–17 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23	12	115	14	14:20
June	28.6	17	96	13	14:57
July	31.8	20.4	111	13	14:43
August	29.7	19.2	86	11	13:45
September	26.2	16	105	10	12:30
October	20.1	10	76	9	11:13
November	12.7	3.4	66	7	10:01

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Hagerstown, Washington, D.C. is 19 days earlier and Pittsburgh 3 days later.

City	Distance	Date	Difference
Washington, D.C.	99 km	4 May – 7 August	19 days earlier
Harrisburg	103 km	25 May – 2 August	2 days later
Baltimore	104 km	5 May – 13 August	18 days earlier
Annapolis	129 km	8 May – 10 August	15 days earlier
Dover	198 km	11 May – 17 August	12 days earlier
Pittsburgh	213 km	26 May – 31 July	3 days later

Where to buy watermelon plants and seeds near Hagerstown

Buy plants ready to set out from 23 May to 2 August (from 2 May to 2 August for an unheated greenhouse); seed for raising your own is sown from 4 April to 5 July. Within 15 km of Hagerstown OpenStreetMap lists 1 garden centre, 2 markets and 2 farm shops (collected 28 October 2026).

Mountain Valley Orchard — farm shop
14 km
Pennsylvania Dutch Market — market
Potomac Avenue 1583, 21742 Hagerstown · 6 km
Lovell's — garden centre
8 km
S&K Mercadito Latino — market
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.

Questions