When to plant eggplants in Boise: 7 May – 7 July

In Boise, eggplant: sow for seedlings from 15 February to 8 May; plant into a greenhouse from 16 April to 7 July; plant out into open ground from 7 May to 7 July. For plants and seeds, the places nearby include North End Organic Nursery (garden centre, 4 km) and Zamzows (garden centre, 5 km); addresses and opening hours are below.

Eggplant in Boise: soil, season and weather

In Boise the soil, not frost, sets the date: the last frost is over around 15 April, but the top 7 cm of soil reaches 18 °C — the minimum on the eggplant card — only around 7 May, 22 days later.

Last spring frost	15 April
Top 7 cm of soil at 18 °C	7 May, 22 days after the last frost
Into an unheated greenhouse	16 April – 7 July; April outside: 4.5 °C at night, 17.6 °C by day; card 21–29 °C
First autumn frost	27 October, 173 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	16 July – 15 September
Days left for picking	103
Daylight	11:31 on 8 March, 14:23 on 7 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, July, has 1 rainy day

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

Eggplant in Boise: care after planting

Planted on 7 May: in the first weeks water every 4 days.

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

7 May — feed: balanced (NPK)
4 June — 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 Boise during the eggplant season

Days average above the eggplant card's 21–29 °C in July (35.1 °C) and August (33.7 °C). Months that stay below 21 °C even by day on average: October (18.2 °C). Nights average below 21 °C in every month of the season, from 6.3 °C to 19.2 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23	9.1	42	8	14:42
June	29	13.9	22	4	15:25
July	35.1	19.2	3	1	15:08
August	33.7	18.1	6	1	14:01
September	27.9	13.1	12	3	12:33
October	18.2	6.3	26	5	11:05

ERA5 2016–2025, Open-Meteo

Eggplant in nearby cities

All the nearest cities on our list plant eggplant later than Boise; the closest date is in Salt Lake City, 12 days later.

City	Distance	Date	Difference
Elko	310 km	20 May – 23 June	13 days later
Idaho Falls	336 km	4 June – 24 June	28 days later
Missoula	400 km	30 June – 28 July	54 days later
Spokane	460 km	22 May – 25 June	15 days later
Helena	466 km	3 July – 25 July	57 days later
Salt Lake City	476 km	19 May – 6 July	12 days later

Where to buy eggplant plants and seeds near Boise

Buy plants ready to set out from 7 May to 7 July (from 16 April to 7 July for an unheated greenhouse); seed for raising your own is sown from 15 February to 8 May. Within 15 km of Boise OpenStreetMap lists 4 garden centres, 2 farm-supply shops and 1 plant nursery (collected 20 October 2026).

Zamzows — farm supply
East Overland Road 3650, 83642 Meridian · 12 km
Zamzows — farm supply
West State Street 6208, 83703 Boise · 8 km
Zamzows — garden centre
South Federal Way 3691, 83716 Boise · Mon–Fri 09:00–19:00; Sun 22:00–17:00; Sat 09:00–18:00 · 5 km
North End Organic Nursery — garden centre
West Chinden Boulevard 3777, 83714 Garden City · 4 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.

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