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USDA Hardiness Zone 4a

Frost Dates for 58047 — Horace, North Dakota

Averages from Fargo 3s, Nd US, the nearest reporting station, 8.1 miles away.

Plant tender crops after May 4, and expect the first autumn freeze around October 2. That leaves about 151 frost-free days.

Last spring frost
May 4

50% probability

First fall frost
October 2

50% probability

Growing season
151 days

frost-free

Hardiness zone
4a

-30 to -25°F annual low

Planting calendar for 58047

What to do and when, based on the frost normals for Horace, North Dakota
WhenWhat to do
February 23 – March 9

Start peppers and aubergines indoors

They need eight to ten weeks under lights before they can go out.

March 9 – March 23

Start tomatoes indoors

Six to eight weeks gives a transplant big enough to set fruit early.

April 6 – April 20

Sow peas, spinach, lettuce, radish outdoors

These tolerate light frost and prefer to germinate in cool soil.

May 4 onward

Transplant tomatoes, peppers, basil, squash, cucumbers

The average last freeze has passed — still watch the actual forecast.

by July 10

Sow the autumn crop of carrots, beets and brassicas

They need about twelve weeks to size up before growth stops.

by September 18

Harvest tender crops, or be ready to cover them

A first freeze two weeks early is well within normal variation.

October 2 onward

Plant garlic, mulch beds, lift tender bulbs

Garlic wants a cold spell; bare soil loses structure over winter.

What these dates mean

Wait until after May 4 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Horace, North Dakota are past their last freeze. Harvest before October 2, which leaves roughly 151 frost-free days.

ZIP 58047 sits in USDA hardiness zone 4a, meaning the average coldest night of the year falls between -30 to -25°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.

These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.

Other zone 4a ZIP codes in North Dakota