Plant Hardiness Zones Got Updated, Here's What To Do...

The new Plant Hardiness Zone map came out for 2023...and things are a bit different. Kevin digs into why this isn't as big a deal as you think, and how zones are not the end-all-be-all of your gardening journey.

IN THIS VIDEO

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TIMESTAMPS
00:00 - Intro
00:21 - What Growing Zones Tell You
01:12 - What They Don't Tell You
01:39 - How Growing Zones Are Determined
02:30 - Microclimates
03:23 - Building A Microclimate

DISCLAIMER

[NicolaiAAA]

I've always thought of plant hardiness zones like the pirates' code - them's more like guidelines than actual rules. xD

[jennhoff]

I would LOVE a zone system for heat. I'm in Houston where it's crazy hot in the Summer. I kept planting things for "Zone 9" and they'd die in the heat. I realized that Seattle is also Zone 9, and the weather is vastly different. Now I look for things that do well in AZ, TX, and FL. And then I find out if they grow within a couple hours of me. I'm having significantly better luck with that.

[floweringevergreen]

As a fellow SoCal gardener, I'm finding that our UV Index is more important than our USDA zone. Our August sun is too intense for a lot of plants supposedly suitable for our zone.

[dudeusmaximus]

The problem with zones is where fall now runs into December when it used to be frozen by Halloween, I used to plant mid-March and now it's more like mid-April. It's a complete shift.

[CandysGarden]

Still Zone 8 in my area, & i don't live by my zone anyways, growing things that don't typically grow in my area. I love to grow what we don't have down here, allowing others to know that they too can grow something that's not typical in their area.😊

[darcyclark]

Totally understand where you're coming from in San Diego, but as a zone 4 (now zone 5), that zone number means a lot more to us because it's all about which perennials can survive our winter and really limits our options for perennials in the garden.

[AustinThomasPhD]

The USDA does map high temps and average annual rainfall etc. (also soils). It is just too much for the average person to process. You aren't going to look a 3-5 different maps to see if you can plant a plant in your backyard. Heat islands and local microclimates are also important as you state.

[apostatepostbox]

Love this! Despite living in 9b, I have HUGE humidity issues due to proximity to the river. Less than a quarter mile away they don't have as much issue with this at all. I often prefer to look for specific things like heat tolerance (tomatoes that can set in long stretches of high heat), drought tolerance, humidity tolerance/disease resistance, etc. Takes a lot more research than just using a zone number, but better results!

[LiinaNiittymaa]

This is an excellent point! I live in southern Finland in a hardiness zone 6a. That may seem great, but actually doesn't tell you the biggest issues we do have here: very short growing seasons (around 90 frost-free days) and lack of sufficient daylight from late Oct to early March. We might not have our winters as cold as in Alaska but our growing conditions sure seem quite similar. So, no winter growing here unless you have a heated greenhouse with growing lights.

[grandmamochi]

Thank you for the deep dive into planting zones. I discovered the micro climates in my garden by observing how plants behave in different parts of the garden by noting their stress and growing levels. As the garden grew and evolved, micro climates changed. Some plants adapted some didn't. Because I live in a subtropical climate, there was no change but I do pay attention to zones just above and below my zone to choose plants to tryout and experiment with.

[melvanini]

I'm really happy to see this. I live in Australia and we don't have that first frost/last frost data for the whole country like you guys do, so I've been keeping track of my own local temperatures to give myself a better idea of that. But it's good to know that it doesn't really matter when you're gardening based on your own space & microclimates.

[MrEzekiel]

Good points. One thing I’ve noticed over the years is that while the cold temps do contribute to plants dying the winter rainfall is a key factor. I have been able to overwinter plants not rated for my zone by adding sand and grit and planting in a dryer spot

[gregleach]

My zone got updated from 8b to 9a . A decent number of years we don’t get below 20 but every few years we get into the teens . Just last Christmas we had an arctic blast and got down to 16 . That’s 8b all day long . I’m not changing anything I plant .

[haidehollins]

Also, zones aren't a big deal when planting native plants. Hardiness zones are definitely a useful guideline, but we can plant just about anything we want. How well it does relies heavily on care, especially in inclimate weather. So many factors, super exciting to learn more!

[cristiewentz]

Thankful here that the temps are oh so gradually warming. We are still coming out of the little ice age...when the Thames used to freeze solid every winter and people could ice skate down the middle...we might one day see Greenland green again, or wine grapes grown along Hadrian's wall...but that's a long time away. Something to look forward to!

[weredragon]

Thank you for confirming this and giving a detailed explanation of hardiness zones and microclimates. Where I live in Western Washington State is considered zone 8b because we are close to the Pacific Ocean. But the Olympic mountains make up most of the of the peninsula so our elevation is substantially higher then sea level.

We are 500 feet above sea level. We get snow every year. I've lived in a lot of places in Western Washington, but I've never seen this much snow. It's also been getting hotter for longer in the summer months. Plants that might survive the colder weather don't do as well in the heat and vice versa. With 2 acres of property in the woods we have quite a few microclimates.

What I do is every year I pick a couple varieties of plants and grow multiple plants of each type in different places. For example last year I grew tomatoes in the garden in the north west of the property. In planters on the south facing yard, and in the greenhouse. The garden was the most productive.

Learn your microclimates and experiment. You know your land the best. 😊

[jugglethis]

Yep...here in our small backyard garden in Bakersfield, CA, we have about 3 different microclimates that I have identified....and one of those has changed with the maturation of the nearby pear trees (providing more shade than they did before)

[CherrieMcKenzie]

You are EXACTLY right about the zones. I checked the map and based on my zip code I am about a mile away from my old zone of 9A and now considered to be in 9B the same zone as Orlando which is 2 hours away. So I think I will still consider myself 9A because it does get colder in my region. Thanks for the info!!

[wleight]

Highly recommend David the Good’s book Pushing the Zone! Covers microclimates very well!

[Tangobutton]

David Francko taught us zone pushers this for a long time in his great book, 'Palms don't grow here and other myths.' I landed on musa basjoo banana in my garden and it dies back in the first frost and comes back in March! (Ann Arbor, Michigan).