Greenly Garden

When to plant bell peppers in Flagstaff: 12 May – 1 July

In Flagstaff, bell pepper: sow for seedlings from 20 February to 2 May; plant into a greenhouse from 21 April to 1 July; plant out into open ground from 12 May to 1 July.

Bell Pepper in Flagstaff: soil, season and weather

In Flagstaff frost, not soil, sets the date: the top 7 cm of soil warms to 18 °C — the minimum on the bell pepper card — around 30 April, 5 days before the last frost on 5 May, so planting waits only for the week after that frost.

Last spring frost5 May
Top 7 cm of soil at 18 °C30 April, 5 days before the last frost
Into an unheated greenhouse21 April – 1 July; April outside: 3 °C at night, 17.4 °C by day; card 15–30 °C
First autumn frost21 October, 162 days after the start
Days in the bed to the first harvest (card)70
First harvest, if planted in this window21 July – 9 September
Days left for picking92
Daylight11:51 on 13 March, 13:55 on 12 May
Watering outdoors when fruiting (card)every 4 days; the driest month, June, has 3 rainy days

The same dates in Flagstaff hold for Tomato, Cucumber, Eggplant, Zucchini, Pumpkin and Watermelon.

Bell Pepper in Flagstaff: care after planting

Planted on 12 May: in the first weeks water every 5 days.

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

  • 12 May — feed: balanced (NPK)
  • 9 June — feed: nitrogen

Pests and diseases of bell pepper 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 Flagstaff during the bell pepper season

No month of the season averages above the bell pepper card's 15–30 °C by day; the warmest, July, averages 29.7 °C. Nights average below 15 °C in May, June and September, October (6–13.7 °C).

MonthDay, °CNight, °CRain, mmRainy daysDaylight on the 15th
May21.4723614:00
June28.413.715314:31
July29.716.5531014:19
August27.815.3511013:30
September24.712.127512:26
October18.4624411:20

ERA5 2016–2025, Open-Meteo

Bell Pepper in nearby cities

All the nearest cities on our list plant bell pepper earlier than Flagstaff; the closest date is in Grand Junction, 6 days earlier.

CityDistanceDateDifference
Phoenix197 km23 February – 8 September78 days earlier
Tucson335 km7 March – 28 August66 days earlier
Las Vegas336 km1 April – 22 August41 days earlier
Albuquerque452 km18 April – 20 July24 days earlier
Grand Junction512 km6 May – 7 July6 days earlier
Santa Fe (United States)518 km3 May – 6 July9 days earlier

Where to buy bell pepper plants and seeds near Flagstaff

Buy plants ready to set out from 12 May to 1 July (from 21 April to 1 July for an unheated greenhouse); seed for raising your own is sown from 20 February to 2 May. Within 15 km of Flagstaff OpenStreetMap lists 1 plant nursery and 1 market (collected 28 October 2026).

Places: © OpenStreetMap contributors, ODbL.

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

When to plant bell peppers in Flagstaff?

In Flagstaff, bell pepper: sow for seedlings from 20 February to 2 May; plant into a greenhouse from 21 April to 1 July; plant out into open ground from 12 May to 1 July.

When to sow bell peppers for seedlings in Flagstaff?

Sow for seedlings from 20 February to 2 May.

When is the last spring frost in Flagstaff?

Last spring frost around 5 May, first autumn frost around 21 October.

Other crops in Flagstaff, with their dates