When to plant pumpkins in Portsmouth: 16 June – 6 August

In Portsmouth, pumpkin: sow for seedlings from 14 April to 25 June; plant into a greenhouse from 26 May to 6 August; plant out into open ground from 16 June to 6 August.

Pumpkin in Portsmouth: soil, season and weather

In Portsmouth the soil, not frost, sets the date: the last frost is over around 4 March, but the top 7 cm of soil reaches 18 °C — the minimum on the pumpkin card — only around 16 June, 104 days later.

Last spring frost	4 March
Top 7 cm of soil at 18 °C	16 June, 104 days after the last frost
First autumn frost	1 December, 168 days after the start
Days in the bed to the first harvest (card)	75
First harvest, if planted in this window	30 August – 20 October
Days left for picking	93
Daylight	14:58 on 5 May, 16:29 on 16 June
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 11 rainy days

The same dates in Portsmouth hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Watermelon.

Pumpkin in Portsmouth: care after planting

Planted on 16 June: in the first weeks water every 4 days.

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

7 July — feed: nitrogen

Pests and diseases of pumpkin 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 Portsmouth during the pumpkin season

About 568 mm of rain falls in the season; June is the driest month (59 mm) and October the wettest (108 mm).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	19	12.8	59	11	16:29
July	20.7	14.9	60	12	16:05
August	20.7	14.8	64	11	14:36
September	18.9	13	79	11	12:42
October	15.5	10.8	108	14	10:47
November	11.7	7.1	100	14	8:59
December	9.7	5.6	98	14	7:59

ERA5 2016–2025, Open-Meteo

Pumpkin in nearby cities

Around Portsmouth, London is 4 days earlier and Brighton 34 days later.

City	Distance	Date	Difference
Southampton	24 km	17 June – 29 July	1 day later
Brighton	67 km	20 July – 6 August	34 days later
London	103 km	12 June – 29 July	4 days earlier
Oxford	105 km	23 June – 29 July	7 days later
Bristol	127 km	19 June – 28 July	3 days later
Cardiff	164 km	24 June – 28 July	8 days later

Where to buy pumpkin plants and seeds near Portsmouth

Buy plants ready to set out from 16 June to 6 August (from 26 May to 6 August for an unheated greenhouse); seed for raising your own is sown from 14 April to 25 June. Within 15 km of Portsmouth OpenStreetMap lists 16 garden centres, 4 plant nurseries, 5 markets and 8 farm shops (collected 28 October 2026).

The Waterfront Garden Centre — garden centre
3 km
Parker’s — garden centre
9 km
Solent Nurseries — garden centre
12 km
Mount Folly Nursery — garden centre
10 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