When to plant pumpkins in Riverside: 2 April – 24 August

In Riverside, pumpkin: sow for seedlings from 29 January to 13 July; plant into a greenhouse from 12 March to 24 August; plant out into open ground from 2 April to 24 August.

Pumpkin in Riverside: soil, season and weather

In Riverside the soil, not frost, sets the date: the last frost is over around 12 January, but the top 7 cm of soil reaches 18 °C — the minimum on the pumpkin card — only around 2 April, 80 days later.

Last spring frost	12 January
Top 7 cm of soil at 18 °C	2 April, 80 days after the last frost
First autumn frost	19 December, 261 days after the start
Days in the bed to the first harvest (card)	75
First harvest, if planted in this window	16 June – 7 November
Days left for picking	186
Daylight	11:06 on 19 February, 12:34 on 2 April
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 0 rainy days

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

Pumpkin in Riverside: care after planting

Planted on 2 April: in the first weeks water every 4 days.

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

23 April — 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 Riverside during the pumpkin season

About 168 mm of rain falls in the season; June is the driest month (1 mm) and December the wettest (69 mm).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	25.8	11.3	19	3	13:01
May	27.2	13	9	3	13:55
June	31.9	15.4	1	0	14:24
July	35.1	18.1	2	0	14:13
August	35.7	18.9	6	1	13:27
September	33.6	17.9	14	2	12:25
October	29.8	14.6	13	3	11:22
November	24.8	10.5	35	3	10:25
December	20.3	7.8	69	5	9:55

ERA5 2016–2025, Open-Meteo

Pumpkin in nearby cities

Around Riverside, Phoenix is 38 days earlier and Santa Barbara 42 days later.

City	Distance	Date	Difference
Bakersfield	217 km	2 April – 19 August	same day
Santa Barbara	218 km	14 May – 20 August	42 days later
Ensenada	243 km	29 March – 19 August	4 days earlier
Las Vegas	321 km	1 April – 17 August	1 day earlier
Fresno	378 km	10 April – 10 August	8 days later
Phoenix	496 km	23 February – 3 September	38 days earlier

Where to buy pumpkin plants and seeds near Riverside

Buy plants ready to set out from 2 April to 24 August (from 12 March to 24 August for an unheated greenhouse); seed for raising your own is sown from 29 January to 13 July. Within 15 km of Riverside OpenStreetMap lists 4 garden centres, 30 plant nurseries, 7 markets and 10 farm shops (collected 28 October 2026).

Pacific Coast Nursery — plant nursery
6 km
Moon Valley Nurseries — plant nursery
6 km
Tienda Tzuluma — market
5 km
India Sweets and Spices — 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