When to plant watermelons in Perth (United Kingdom): 19 July – 2 August

In Perth (United Kingdom), watermelon: sow for seedlings from 31 May to 5 July; plant into a greenhouse from 28 June to 2 August; plant out into open ground from 19 July to 2 August.

Watermelon in Perth (United Kingdom): soil, season and weather

In Perth (United Kingdom) the soil, not frost, sets the date: the last frost is over around 28 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 19 July, 82 days later. 115 days separate planting out (19 July) from the first autumn frost (11 November); the card's 59 days to the first harvest leave 56 for picking, so a start 8 weeks late would still fit.

Last spring frost	28 April
Top 7 cm of soil at 18 °C	19 July, 82 days after the last frost
Into an unheated greenhouse	28 June – 2 August; June outside: 9.1 °C at night, 17 °C by day; card 18–35 °C
First autumn frost	11 November, 115 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	16 September – 30 September
Days left for picking	56
Daylight	17:44 on 21 June, 16:57 on 19 July
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 14 rainy days

The same dates in Perth (United Kingdom) hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Perth (United Kingdom): care after planting

Planted on 19 July: in the first weeks water every 5 days.

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

19 July — 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 Perth (United Kingdom) during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 18.5 °C. Months that stay below 18 °C even by day on average: August–November (8–17.8 °C). Nights average below 18 °C in every month of the season, from 2.5 °C to 10.7 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
July	18.5	10.7	98	15	17:09
August	17.8	10.4	101	15	15:12
September	15.6	8.5	88	14	12:50
October	11.9	6	129	16	10:30
November	8	2.5	98	15	8:14

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Perth (United Kingdom), Edinburgh is 13 days earlier and Dundee 2 days later.

City	Distance	Date	Difference
Dundee	29 km	21 July – 3 August	2 days later
Stirling	44 km	11 July – 31 July	8 days earlier
Edinburgh	52 km	6 July – 31 July	13 days earlier
Glasgow	79 km	21 July – 2 August	2 days later
Aberdeen	115 km	19 July – 11 August	same day
Inverness	129 km	17 July – 4 August	2 days earlier

Where to buy watermelon plants and seeds near Perth (United Kingdom)

Buy plants ready to set out from 19 July to 2 August (from 28 June to 2 August for an unheated greenhouse); seed for raising your own is sown from 31 May to 5 July. Within 15 km of Perth (United Kingdom) OpenStreetMap lists 6 garden centres, 2 farm-supply shops, 1 market and 5 farm shops (collected 28 October 2026).

Gloagburn Farm Shop and Cafe — farm shop
7 km · gloagburnfarmshop.co.uk
Broadslap Fruit Farm — farm shop
15 km · broadslapfruitfarm.co.uk
Jamesfield Organic Centre — farm shop
11 km
Fruitshack (summer only) — farm shop
12 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