When to plant hyacinths in Flagstaff: 21 September – end of December

In Flagstaff, hyacinth: plant from 21 September to the end of December.

Bulbs are best planted early in the window: late-planted bulbs may flower later or less well. Late planting works only while the soil can be dug. Mulch after planting.

The average daily temperature here falls below 0 °C only in January; the sources go no later than December. Sources: Iowa State University Extension, Wisconsin Horticulture Extension, UNH Extension, RHS, how the ground freezes (NRC Canada, CBD-26).

Hyacinth in Flagstaff: soil, season and weather

Nights then average below 0 °C in December–March; the coldest, January, averages -5 °C.

Planting	21 September – end of December
First autumn frost	21 October
Coldest nights	January, -5 °C
Soil back at 1 °C in spring	18 January
Daylight	12:13 on 21 September
Daylight at the winter solstice	9:47

The same dates in Flagstaff hold for Garlic, Tulip, Daffodil and Crocus.

Hyacinth in Flagstaff: depth, winter cold, pests and pets

Plant hyacinths 10 cm deep, at least 7.5 cm apart (RHS). In the ground hyacinths are fully hardy, but in containers they can be frost tender in cold winters (RHS); here winter nights average below 0 °C, so wrap the pots or move them to a sheltered spot.

In Flagstaff the average daily temperature stays at 10 °C or lower for about 24 weeks a year (our estimate from ten years of monthly weather). For this bulb Wisconsin Horticulture Extension gives a cold period of 12–15 weeks at about 2–10 °C. The winter here gives that in the ground, so the bulbs need no pre-chilling.

Flowers get smaller in the years after planting: for full spikes, replace the bulbs or add a few new ones each autumn (RHS).

If squirrels are a problem, protect the bulbs with wire mesh (RHS). Hyacinths are toxic to dogs, cats and horses: intense vomiting and diarrhoea (ASPCA).

Sources: RHS, Wisconsin Horticulture Extension, ASPCA.

Hyacinth in nearby cities

All the nearest cities on our list plant hyacinth later than Flagstaff; the closest date is in Santa Fe (United States), 5 days later.

City	Distance	Date	Difference
Las Vegas	336 km	by 12 November	52 days later
Albuquerque	452 km	10 October – end of December	19 days later
Grand Junction	512 km	27 September – 7 December	6 days later
Santa Fe (United States)	518 km	26 September – 11 December	5 days later
Las Cruces	550 km	by 25 October	34 days later
Ciudad Juárez	619 km	by 5 November	45 days later

Where to buy hyacinth for planting in Flagstaff

Planting stock goes into the ground from 21 September to the end of December; buy it before that. Within 15 km of Flagstaff OpenStreetMap lists 1 plant nursery and 1 market (collected 28 October 2026).

Sprouts Farmers Market — market
South Riordan Ranch Street 1540, 86001 Flagstaff · Mon–Sun 07:00–22:00 · 4 km · sprouts.com
Viola's Flower Garden — plant nursery
8 km

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