When to plant tomatoes in Siena: 22 April – 7 August

In Siena, tomato: sow for seedlings from 8 February to 16 June; plant into a greenhouse from 1 April to 7 August; plant out into open ground from 22 April to 7 August. For plants and seeds, the places nearby include Piante e Fiori l'Hibiscus (plant nursery, 2 km) and Brico & Garden (garden centre, 3 km); addresses and opening hours are below.

Tomato in Siena: soil, season and weather

In Siena the soil, not frost, sets the date: the last frost is over around 16 March, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 22 April, 37 days later.

Last spring frost	16 March
Top 7 cm of soil at 15 °C	22 April, 37 days after the last frost
Into an unheated greenhouse	1 April – 7 August; April outside: 6.9 °C at night, 18.9 °C by day; card 16–27 °C
First autumn frost	27 November, 219 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	1 July – 16 October
Days left for picking	149
Daylight	11:11 on 1 March, 13:43 on 22 April
Watering outdoors when fruiting (card)	every 3 days; the driest month, July, has 4 rainy days

Tomato in Siena: care after planting

Planted on 22 April: in the first weeks water every 4 days.

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

22 April — feed: balanced (NPK)
20 May — feed: nitrogen

Pests and diseases of tomato 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 Siena during the tomato season

Days average above the tomato card's 16–27 °C in June (29.1 °C), July (32.5 °C) and August (32.4 °C). Months that stay below 16 °C even by day on average: November (15.2 °C). Nights average below 16 °C in April, May and September–November (6.2–14.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	18.9	6.9	56	9	13:23
May	22.5	11	91	12	14:40
June	29.1	16	41	7	15:23
July	32.5	18.8	22	4	15:06
August	32.4	18.9	35	6	14:00
September	26.5	14.8	77	8	12:33
October	21.4	10.9	97	8	11:05
November	15.2	6.2	107	12	9:44

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

Around Siena, Livorno is 2 days earlier and Pisa 38 days later.

City	Distance	Date	Difference
Arezzo	47 km	23 May – 1 August	31 days later
Florence	50 km	3 May – 7 August	11 days later
Livorno	84 km	from 20 April	2 days earlier
Pisa	87 km	30 May – 29 July	38 days later
Perugia	89 km	9 May – 5 August	17 days later
San Marino	113 km	25 April – 22 August	3 days later

Where to buy tomato plants and seeds near Siena

Buy plants ready to set out from 22 April to 7 August (from 1 April to 7 August for an unheated greenhouse); seed for raising your own is sown from 8 February to 16 June. Within 15 km of Siena OpenStreetMap lists 3 garden centres, 2 farm-supply shops, 4 plant nurseries, 6 markets and 1 farm shop (collected 27 October 2026).

Mundi — garden centre
Viale Europa 51, 53100 Siena · 3 km · shop.mundi.it
Brico & Garden — garden centre
Via delle Arti 27, 53100 Siena · 3 km · bricook.it
Piante e Fiori l'Hibiscus — plant nursery
Strada Massetana Romana 7, 53100 Siena · 2 km
Sena Flora — plant nursery
Via Arno 2, 53018 Sovicille · 7 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