When to plant eggplants in Hamamatsu: 2 May – 28 August

In Hamamatsu, eggplant: sow for seedlings from 10 February to 29 June; plant into a greenhouse from 11 April to 28 August; plant out into open ground from 2 May to 28 August.

Eggplant in Hamamatsu: soil, season and weather

In Hamamatsu the soil, not frost, sets the date: the last frost is over around 24 February, but the top 7 cm of soil reaches 18 °C — the minimum on the eggplant card — only around 2 May, 67 days later.

Last spring frost	24 February
Top 7 cm of soil at 18 °C	2 May, 67 days after the last frost
Into an unheated greenhouse	11 April – 28 August; April outside: 10.4 °C at night, 19.4 °C by day; card 21–29 °C
First autumn frost	18 December, 230 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	11 July – 6 November
Days left for picking	160
Daylight	11:30 on 3 March, 13:36 on 2 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, December, has 6 rainy days

The same dates in Hamamatsu hold for Cucumber, Bell Pepper, Zucchini, Pumpkin and Watermelon.

Eggplant in Hamamatsu: care after planting

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

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

2 May — feed: balanced (NPK)
30 May — feed: nitrogen

Pests and diseases of eggplant 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 Hamamatsu during the eggplant season

Days average above the eggplant card's 21–29 °C in July (29.9 °C) and August (31.3 °C). Months that stay below 21 °C even by day on average: November (18 °C) and December (12.4 °C). Nights average below 21 °C in May, June and October–December (4–18.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23.2	14.6	244	12	13:58
June	26.1	18.8	357	15	14:28
July	29.9	23.3	310	16	14:16
August	31.3	24.4	218	17	13:29
September	28.2	21.3	277	18	12:26
October	23	15.4	227	14	11:21
November	18	9.4	117	9	10:22
December	12.4	4	71	6	9:51

ERA5 2016–2025, Open-Meteo

Eggplant in nearby cities

Around Hamamatsu, Tokyo is 4 days earlier and Niigata 18 days later.

City	Distance	Date	Difference
Nagoya	92 km	6 May – 20 August	4 days later
Kyoto	182 km	14 May – 17 August	12 days later
Osaka	204 km	5 May – 27 August	3 days later
Tokyo	209 km	28 April – 24 August	4 days earlier
Okayama	348 km	14 May – 25 August	12 days later
Niigata	376 km	20 May – 30 August	18 days later

Where to buy eggplant plants and seeds near Hamamatsu

Buy plants ready to set out from 2 May to 28 August (from 11 April to 28 August for an unheated greenhouse); seed for raising your own is sown from 10 February to 29 June. Within 15 km of Hamamatsu OpenStreetMap lists 5 garden centres, 6 farm-supply shops, 5 markets and 39 farm shops (collected 28 October 2026).

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