Which USDA Climate Zone Covers Idaho Falls?

Have you checked the USDA plant hardiness map lately?

Okay, we knew it was a long shot. It’s not exactly the most exciting reading.

But this tool, created by the U.S. Department of Agriculture, is convenient, helping you figure out what plants can thrive and survive in your region of the country.

Jump to Section

• First, What Exactly Is the USDA Plant Hardiness Zone Map
• What Does Zone 5b Mean?
• What Are the Best Plants for Idaho Falls Climate?
• Can You Plant Plants That Aren’t Ideal for Your Growing Zone?
• Other Factors When You’re Planting and Landscaping in Idaho Falls
• Looking for the Best Plants for Your Idaho Falls Climate? Trust Outback

What is the growing zone for Idaho Falls? According to the 2023 USDA Hardiness Zone Map, Idaho Falls is in Zone 5b, with average low temperatures of -15 to -10 degrees. This is a change from the 2012 map, which placed Idaho Falls in zones 5a, with average low temperatures of -20 to -15, and 5b.

About half of the United States, including here in Idaho Falls, shifted into a new zone with the plant hardiness map update. Most places are a bit warmer than they used to be.

What does that mean for you and your Idaho backyard?

Let’s take a look, with help from Outback Landscape designer and plant pro Kim Rubert, who shares how Outback landscape designers find plants that will thrive in your landscaping, despite the wild temperature swings in Idaho Falls.

Keep reading to learn more about the best plants for Idaho Falls’ climate, including:

First, What Exactly Is the USDA Plant Hardiness Zone Map?

The USDA Plant Hardiness Zone Map
is the tool that everybody from plant growers to gardeners to landscapers uses to figure out which plants are most likely to thrive in each area of the country.

The map divides the country into zones defined by their average coldest winter temperatures, focusing on plant survival down to the lowest average temperatures where you live.

It’s a thorough map, with the climate zones for landscaping divided into 10-degree increments and then subdivided into “a” and “b” sections, each representing a 5-degree Fahrenheit difference.

For example, the coldest zone is 2b, in Minnesota, and the warmest is in Puerto Rico, at 13b, with the rest of the country falling somewhere in between.

Why is this so helpful? The map helps you choose plants that are most likely to survive the winter in your area of the country.

When you buy that purple coneflower or hosta at the garden center, its tag will tell you the USDA growing zones information, so you know if it will survive in your yard and not get killed by frost.

This handy plant growing zones map has been around since 1960, and it hasn’t changed very much during that time. The climate zones for landscaping remained reliably the same.

But in November 2023, there was big news that made plant lovers everywhere think, “Whoa.” The USDA updated its plant hardiness zone map for the first time since 2012, based on the changing climate.

Lots of places are warmer than they used to be — including Idaho Falls.

If you compare the new 2023 version of the map to the 2012 map, you’ll see that about half of the country moved to the next warmer half-zone.

You can search the 2023 USDA Plant Hardiness Zone Map by zip code to see if your area has changed since 2012.

What Does Zone 5b Mean?

Now that Idaho Falls has scooted into zone 5b, it means that the average annual extreme low winter temperature here is between -15 and -10 degrees Fahrenheit.

The "b" designation indicates the warmer half of the overall Zone 5 temperature range, and Zone 5a represents the colder half.

What does this change in the USDA growing zones mean? Rubert explains.

“Idaho Falls moved from 5a and 5b to more solidly a 5b, that reflects slightly warmer winters,” she says. In fact, some plants from the even warmer zone 6 are becoming more viable here, Rubert says, especially if they’re planted in sheltered microclimates. (More about this in a bit.)

“But we still need to plan for extremes,” she says. “One bad cold snap can wipe out plants that are marginally hardy.”

Idaho’s diverse temperatures have always made choosing plants tricky for landscaping in Idaho Falls, Rubert says.

“We have quite a range of temperatures,” she says. “Even though the growing zone for Idaho Falls technically got warmer, we still have summers with temps in the 90s and winters with temps often below zero.” And wind chill can make things even harsher, she notes.

“We need species that can handle the freezing winters, yet won’t fry in our short but intense summers,” Rubert says. “This means tough perennials, hardy shrubs, and trees with wide tolerance ranges.”

It’s a challenge, she says.

“Many plants thrive in the summer, but die back in the winter — or they survive in the cold, but can't take the heat or dry spells,” she says. “We look for cold-hardy perennials that come back year after year, hardy evergreens that provide structure through the winter, and deciduous trees or shrubs that can withstand freeze-thaw cycles and add seasonal interest.”

Luckily, many of her favorite plants meet the criteria: Swedish aspen, dogwoods, arborvitae, Norway spruce, phlox, catmint, asters, and ornamental grasses.

“Those plants definitely still work well here,” Rubert says. “We can expand our plant palette a little more as the climate shifts.”

But not too much. Rubert still chooses plants she calls “tried and true,” selecting species she’s confident will survive the cold, the heat, and the occasional drought conditions that Idaho Falls dishes out through the seasons.

What Are the Best Plants for Idaho Falls Climate?

A few Rubert favorites always make the cut:

Swedish Aspen

Hardy and with pretty fall color, Swedish Aspen has rounded leaves that rustle in the breeze, tolerates drought and poor soil and needs minimal pruning.

Arborvitae

Arborvitae are a classic landscape choice. They don't require extensive pruning or care, and there are so many varieties to choose from, you’re sure to find one you like.

‘Autumn Brilliance’ Serviceberry

A smaller tree, this beauty offers showy white flowers in spring and pretty purple berries in June that birds love. Its glossy blue-green leaves turn brilliant red-orange in autumn, adding multi-season interest.

Ninebark

Rubert loves this great medium-sized Idaho native shrub, which will show off clusters of pretty white flowers in late spring and light rose fall color. Bonus: it’s drought-tolerant.

Scotch Bluebell

This Idaho native is as pretty as it sounds, with clusters of bright blue bell-shaped flowers on a compact plant that will happily spread. It blooms for a solid four to six weeks.

Coneflower

The ultimate easy-going plant, coneflower thrives in full sun and partial shade. Birds, bees and butterflies love it. Pick your favorite color, from purple or pink to white, yellow and orange. Plant them in masses for a real show, then leave the tasty seed heads to make your hungry backyard birds happy.

Just a few of the other safe bets that match up with the plant hardiness zone map for Idaho Falls:

• ‘Baby Blue’ Spruce
• Chanticleer Pear
• Burning Bush
• Oregon Grape
• ‘Gold Mound’ Spirea
• ‘Tiger Eyes’ Sumac
• Columbine
• Shasta Daisy
• Black Eyed Susan
• Daylilies

Can You Plant Plants That Aren’t Ideal for Your Growing Zone?

You can, but why take the risk when there are plenty of tried-and-true plants that thrive here?

Rubert talked earlier about planting plants that thrive in zone 6, even though Idaho Falls is in zone 5. She mentioned planting these plants that need warmer winter temperatures in “microclimates.”

What does that mean?

A microclimate is a small area where the climate conditions, like temperature, humidity, and wind, differ from those of its surrounding larger climate zones.

You might have a microclimate in your own backyard.

A south-facing slope might be warmer and drier than a north-facing one. An area of your property shielded from wind by a building or a wall can develop a warmer microclimate than an area of your yard that’s exposed.

If you have this kind of warmer microclimate, you might be able to get away with a zone 6 plant, Rubert says, even though you live in zone 5 on the USDA growing zones map.

Other Factors When You’re Planting and Landscaping in Idaho Falls

While the USDA planting zones play a crucial part in choosing plants that will survive and thrive, other factors are important, too.

Just because you picked a plant that works in your plant hardiness zone, it isn’t a guarantee that it will survive in your landscaping.

Those same plant tags that tell you what planting zone ninebark or coneflower needs will give you other important information, too.

Does it need sun or shade? How much water will it need? If you’re planting more than one, how far apart should you space them? How big will it get at maturity?

These are all factors you need to consider before deciding if a plant will thrive, in addition to making sure it’s suited for your planting zone.

Rubert offers a few other tips, too, when planting in Idaho Falls:

• Winter in Idaho brings snow along with those icy, low temperatures. Don’t plant fragile shrubs or ornamental trees near the edge of your house where snow will fall from the roof and crush them.
• Snow means snow plows. Don’t plant fragile shrubs where snow plows will damage them. Consider perennials, such as sturdy ornamental grasses, for areas near driveways and sidewalks instead.
• Use proper spacing, following the instructions on those plant tags. Don’t crowd plants too close together, and don’t plant them too close to your house. Take note of how big they’ll be when they’re full-grown — not what they look like when you plant them.

• Take note of the plant’s sunlight and water needs and group plants with similar needs together when you’re planting in Idaho Falls.

Looking for the Best Plants for Your Idaho Falls Climate? Trust Outback

Does all this talk of plant hardiness zones make you zone out?

Leave the maps to us. Professional designers like Rubert can help with all this and ensure that the plants in your landscaping are beautiful, healthy and will survive the highs and lows of the wide-ranging Idaho Falls climate.

Located in Idaho Falls, Idaho, we serve residential and commercial properties in Idaho Falls, Rexburg and Pocatello, Idaho, as well as Bonneville, Madison and Bannock counties. Reach us at 208-656-3220, or contact us to schedule a consultation. We’d love to hear from you.