Metro areas

Gardening in Logan, UT-ID

This metro spans USDA zones 5b to 6b, so there is no single zone for Logan, UT-ID and anyone who gives you one is rounding. 91% of its ZIP codes are zone 6a; the rest are not.

USDA zones 5b–6b 3 zones across 23 ZIP codes
ZIP codes 23 23 have a NOAA station within range
Weather stations 10 NOAA 1991–2020 normals, across 1,828 sq mi

Which zone you are in depends where you are

Logan, UT-ID covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 91% in zone 6a and wrong for the other 9%. Here is the actual split.

Zone ZIP codes Share  
6a 21 91%
5b 1 4%
6b 1 4%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze April 30 – June 17
First fall freeze September 3 – October 16

Those are the earliest and latest medians among the 10 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 10 stations serving Logan, UT-ID it runs 77–166 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 81–87 °F , below the 90 °F point where cool-season crops reliably bolt.

When to start seeds in Logan, UT-ID

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 10 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.

Crop Job When Offset
Green Onions Start indoors March 5 – April 22 8 weeks before
Peppers Start indoors March 5 – April 22 8 weeks before
Broccoli Start indoors March 19 – May 6 6 weeks before
Cabbage Start indoors March 19 – May 6 6 weeks before
Collards Start indoors March 19 – May 6 6 weeks before
Kale Start indoors March 19 – May 6 6 weeks before
Leaf Lettuce Start indoors March 19 – May 6 6 weeks before
Peas Direct sow March 19 – May 6 6 weeks before
Spinach Direct sow March 19 – May 6 6 weeks before
Sweet Potato Start indoors March 19 – May 6 6 weeks before
Tomatoes Start indoors March 19 – May 6 6 weeks before
Bok Choy Start indoors March 26 – May 13 5 weeks before
Kohlrabi Start indoors March 26 – May 13 5 weeks before
Swiss Chard Start indoors March 26 – May 13 5 weeks before
Arugula Direct sow April 2 – May 20 4 weeks before
Baby Salad Greens Direct sow April 2 – May 20 4 weeks before
Beets Direct sow April 2 – May 20 4 weeks before
Green Onions Direct sow April 2 – May 20 4 weeks before
Mustard Greens Direct sow April 2 – May 20 4 weeks before
Okra Start indoors April 2 – May 20 4 weeks before
Radishes Direct sow April 2 – May 20 4 weeks before
Turnips Direct sow April 2 – May 20 4 weeks before
Cabbage Set out April 9 – May 27 3 weeks before
Carrots Direct sow April 9 – May 27 3 weeks before
Collards Direct sow April 9 – May 27 3 weeks before
Collards Set out April 9 – May 27 3 weeks before
Cucumbers Start indoors April 9 – May 27 3 weeks before
Green Onions Set out April 9 – May 27 3 weeks before
Kale Direct sow April 9 – May 27 3 weeks before
Kale Set out April 9 – May 27 3 weeks before
Kohlrabi Direct sow April 9 – May 27 3 weeks before
Kohlrabi Set out April 9 – May 27 3 weeks before
Leaf Lettuce Direct sow April 9 – May 27 3 weeks before
Pumpkins Start indoors April 9 – May 27 3 weeks before
Summer Squash Start indoors April 9 – May 27 3 weeks before
Winter Squash Start indoors April 9 – May 27 3 weeks before
Zucchini Start indoors April 9 – May 27 3 weeks before
Bok Choy Direct sow April 16 – June 3 2 weeks before
Bok Choy Set out April 16 – June 3 2 weeks before
Broccoli Set out April 16 – June 3 2 weeks before
Cilantro Direct sow April 16 – June 3 2 weeks before
Leaf Lettuce Set out April 16 – June 3 2 weeks before
Swiss Chard Direct sow April 16 – June 3 2 weeks before
Swiss Chard Set out April 16 – June 3 2 weeks before
Dill Direct sow April 23 – June 10 1 week before
Bush Beans Direct sow May 7 – June 24 1 week after
Cucumbers Set out May 7 – June 24 1 week after
Pumpkins Direct sow May 7 – June 24 1 week after
Pumpkins Set out May 7 – June 24 1 week after
Summer Squash Direct sow May 7 – June 24 1 week after
Summer Squash Set out May 7 – June 24 1 week after
Sweet Corn Direct sow May 7 – June 24 1 week after
Tomatoes Set out May 7 – June 24 1 week after
Winter Squash Direct sow May 7 – June 24 1 week after
Winter Squash Set out May 7 – June 24 1 week after
Zucchini Direct sow May 7 – June 24 1 week after
Zucchini Set out May 7 – June 24 1 week after
Cucumbers Direct sow May 14 – July 1 2 weeks after
Okra Direct sow May 14 – July 1 2 weeks after
Okra Set out May 14 – July 1 2 weeks after
Peppers Set out May 14 – July 1 2 weeks after
Southern Peas Direct sow May 14 – July 1 2 weeks after
Sweet Potato Set out May 14 – July 1 2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Logan, UT-ID

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 51 come through the winter in zone 6a and only 48 in zone 5b. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
5b 1 48 of 74 0
6a 21 51 of 74 0
6b 1 51 of 74 0

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 10 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Bern, ID USC00100803 June 17 September 3 77 days
Cutler Dam, UT USC00421918 May 3 October 12 160 days
Logan 5 SW Exp Farm, UT USC00425194 May 12 September 28 138 days
Logan Cache AP, UT USW00094128 May 8 October 2 144 days
Logan Radio Kvnu, UT USC00425182 May 8 October 2 145 days
Logan Utah St Univ, UT USC00425186 April 30 October 16 166 days
Malad City, ID USW00024151 May 22 September 20 116 days
Preston, ID USC00107346 May 16 September 28 133 days
Richmond, UT USC00427271 May 11 October 5 143 days
Trenton, UT USC00428828 May 17 September 18 121 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

All metro areas