When to plant tomatoes in Grand Junction: 25 April – 7 July

In Grand Junction, tomato: sow for seedlings from 11 February to 16 May; plant into a greenhouse from 4 April to 7 July; plant out into open ground from 25 April to 7 July. For plants and seeds, the places nearby include Mesa Mycology Center (garden centre, 4 km) and Upland Gravel LLC (garden centre, 5 km); addresses and opening hours are below.

Tomato in Grand Junction: soil, season and weather

In Grand Junction frost, not soil, sets the date: the top 7 cm of soil warms to 15 °C — the minimum on the tomato card — around 24 April, 6 days after the last frost on 18 April, so planting waits only for the week after that frost.

Last spring frost	18 April
Top 7 cm of soil at 15 °C	24 April, 6 days after the last frost
Into an unheated greenhouse	4 April – 7 July; April outside: 4.6 °C at night, 19.9 °C by day; card 16–27 °C
First autumn frost	27 October, 185 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	4 July – 15 September
Days left for picking	115
Daylight	11:26 on 4 March, 13:36 on 25 April
Watering outdoors when fruiting (card)	every 3 days; the driest month, June, has 3 rainy days

Tomato in Grand Junction: care after planting

Planted on 25 April: in the first weeks water every 4 days.

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

25 April — feed: balanced (NPK)
23 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 Grand Junction during the tomato season

Days average above the tomato card's 16–27 °C in June–September (28.9–35.1 °C). Nights average below 16 °C in April, May and September, October (4.6–13.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	19.9	4.6	35	7	13:12
May	25.4	9.7	30	6	14:18
June	32.8	16.4	13	3	14:54
July	35.1	19.8	15	2	14:40
August	33.3	18.3	24	5	13:44
September	28.9	13.8	28	5	12:29
October	19.6	6.1	54	7	11:14

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

All the nearest cities on our list plant tomato later than Grand Junction; the closest date is in Pueblo, 3 days later.

City	Distance	Date	Difference
Denver	316 km	8 May – 25 June	13 days later
Colorado Springs	326 km	13 May – 25 June	18 days later
Salt Lake City	339 km	7 May – 6 July	12 days later
Fort Collins	340 km	14 May – 1 July	19 days later
Pueblo	356 km	28 April – 8 July	3 days later
Cheyenne	392 km	25 May – 23 June	30 days later

Where to buy tomato plants and seeds near Grand Junction

Buy plants ready to set out from 25 April to 7 July (from 4 April to 7 July for an unheated greenhouse); seed for raising your own is sown from 11 February to 16 May. Within 15 km of Grand Junction OpenStreetMap lists 5 garden centres, 1 farm-supply shop, 1 market and 1 farm shop (collected 28 October 2026).

Upland Gravel LLC — garden centre
28 1/2 Road 454, 81501 Grand Junction · Mon closed; Tue–Fri 07:00–17:00; Sat 09:00–15:00; Sun closed · 5 km · uplandgravel.com
Meadowlark Garden — garden centre
Broadway 2259, 81507 Grand Junction · Tue–Sun 08:30–17:30 · 6 km · meadowlarkgardencenter.com
Mount Garfield Greenhouse & Nursery — garden centre
F Road 3162, 81504 Grand Junction · Mar, Jul–Oct Mon–Sat 09:00–17:30; Mar, Jul–Oct Sun 10:00–16:00; Apr–May Mon–Sat 08:00–18:00; Apr–May Sun 10:00–17:00; Jun Mon–Sat 09:00–18:00; Jun Sun 10:00–16:00; Jul 04 closed · 9 km · mtgarfieldgreenhouse.com
Mesa Mycology Center — garden centre
North Avenue 2863, 81501 Grand Junction · Mon–Fri 10:00–18:00; Sat 12:00–16:00; Sun closed · 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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