Growing plants from foreign lands with similar climate zone

Im guessing this is stupid question but Ill ask anyway. My zone is 9A, Im assuming that means if looking at a globe any other country that lines up with me is also zone 9A no matter where in the world? If thats true than whats to stop anyone from buying plants from other countries and importing?

Im assuming govt regulations dont allow it, Im assuming that there are some very valid reasons for this and many maybe some not so valid but regardless any responsible adult should use caution when considering anything from a different country because of course we dont want to screw up our own ecosystems any worst than it already is.

I ask this cause I read as much as I can, I love history and I read such and such person imported suchnsuch plant in 18sumpthorother and he went down in history as the original importer.

Id like to try different plants from other countries ( edibles ) I read people all the time on you tube asking other people to help them with cuttings ect and so Im confused.

Thanks and have a nice evening

As you have correctly identified, regulations can come into play.  Another issue is what you mean by lines up.  If you are thinking in terms of drawing a circle around the globe of the same latitude as your home, then no. I am in the southern tip of Illinois. Latitude wise I sit south of Frankfort, KY, but there are places in Idaho in a warmer zone.  Then, there are the issues of water, soil, etc

John F Dean wrote:As you have correctly identified, regulations can come into play.  Another issue is what you mean by lines up.  If you are thinking in terms of drawing a circle around the globe of the same latitude as your home, then no. I am in the southern tip of Illinois. Latitude wise I sit south of Frankfort, KY, but there are places in Idaho in a warmer zone.  Then, there are the issues of water, soil, etc

No kidding, than I was wrong, yes I assumed drawing a circle around the globe ect. Now I feel dumber but thanks anyway

Most of what we eat in USA isn't native and was imported by someone.
Flour/Wheat was imported vs Corn
Chicken were imported vs Ducks
Cows were imported vs Buffalo
Honey-bees were imported
Sugar-cane were imported from Asia vs Maple Syrup
Table/Wine Grape were imported vs Muscadine grapes
Apples were imported from Europe
Pears were imported from Europe and Asia
Oranges were imported from Asia
Banana were imported from Asia

Other than corn, potatoes and peanuts/cashew/pecan everything else was imported.

This is probably due to the fact that most people who live in the Americas are not Native to here but were imported/deported/emigrated to the Americas.

But the short answer to your original question is YES, you can import them and they will grow here.
If they are exotics annuals (think vegetables), they they will grow from zone4 Maine to Zone10 Miami
Some zone 9 differ alot. Plants that require alot of rain in zone9 Florida will not do too well in the desert of Zone9 Arizona and visa-versa
Plants that do well in calcium rich limestone soil, might do poor in acidic soils, or saline desert soils.
Zone 9 in Seattle has very little sunlight... so nothing ripens, but Zone 9 in Arizona needs a shade cloth due to excessive sunlight
But given that you are going to create an amended environment for the plants, maybe even create your own landrace, then I think you should go for it.

At the equator in both Somalia and Ecuador, you will find two very different climates, one is a zone 1 glacier filled mountain and the other is a zone 15 desert. So latitudes isn't always the best way to tell the zone. Both England and Florida are zone 10.  

Hi Jason,
You asked about other climates similar to your own.

I enjoy using the Koppen climate classification system (https://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification) for several things, including this.

With it, one can see similarities in areas with similar latitudes and relative positions on their continents. For instance, the Southeast US is shown to have a similar climate to Southeast China.

Happy planting!

yup. hardiness zones are just based on average lowest temperature, so two places 'in the same zone' can have very different climates otherwise - thus there are places way up the west coast whose lowest winter temperatures are similar to parts of georgia...but all the same crops don't do as well in both places. elevation, proximity to bodies of water, and more can affect 'zones'.

Im glad I asked, dosent seem like such a stupid question after all. Thanks

More often than not, you will find that someone will import a specific cultivar from another country, that did okay (most likely with some other cultivar nearby, to give pollen).

Then that imported cultivar will have 1 AMAZING offspring out of 500 offspring/year over 10years (1:5000). Their kids/friends will then name that 1 amazing offspring/cultivar after them, saying that they got it from such and such country.

Developing a new landrace/cultivar that is locally adapted to your climate/soil/chillhours/GDD/AHS/etc is really cool and you can name that cultivar after yourself, it's even cooler if you have an amazing story to go along with. Such as you smuggled it in during the covid crsis of 2020, after finishing up a XYZ, in such and such country, where you ultimately met the partner of your dreams.

S Bengi wrote:More often than not, you will find that someone will import a specific cultivar from another country, that did okay (most likely with some other cultivar nearby, to give pollen).

Then that imported cultivar will have 1 AMAZING offspring out of 500 offspring/year over 10years (1:5000). Their kids/friends will then name that 1 amazing offspring/cultivar after them, saying that they got it from such and such country.

Developing a new landrace/cultivar that is locally adapted to your climate/soil/chillhours/GDD/AHS/etc is really cool and you can name that cultivar after yourself, it's even cooler if you have an amazing story to go along with. Such as you smuggled it in during the covid crsis of 2020, after finishing up a XYZ, in such and such country, where you ultimately met the partner of your dreams.

Id like to smuggle in some bamboo!!! I still cant wrap my head around what people are asking for the stuff. 20 rhizome cuttings for 300$ How can that be justified, brings to mind I just replaced for customer a f-250 tailgate finish panel.... the large one in the middle of the gate that says platinum! 1600 dollars for that piece of plastic! Again how or on what planet can that be justified?

As mentioned above, you want to look at the Koppen climate classifications. Just picking similar latitude locations around the world doesn't work at all. Crazy as it sounds, my site in SW MI has a climate similar to a province on one of Japan's northern islands. Wouldn't have found that on my own. But it tells me we really can expect to grow rice here, and maybe raise koi ;)  It's an excellent tool for exactly the reasons you're thinking about.

General information on importing plants into the US:

Plant imports are regulated by USDA APHIS. The main concerns when importing plants are potential to become invasive or take over an ecosystem and the potential to carry in diseases and pests that are deadly to native species.  

This is a manual for importing "plants for planting": https://www.aphis.usda.gov/import_export/plants/manuals/ports/downloads/plants_for_planting.pdf
The PDF can be searched by pressing ctrl F in windows. Searching for genus or common name will let you know if your desired plant needs an import permit or if it is prohibited. 

It's also a good idea to check the Fruits and Vegetables Import Requirements: https://epermits.aphis.usda.gov/manual/index.cfm?CFID=311149&CFTOKEN=a6d35a16dc568173-2CD2C719-AE84-FA11-19BE0470C87FB5C9&ACTION=pubHome
Results will tell you what parts of the plant are regulated and what countries of origin are regulated. 

When buying from an individual or business overseas, it's a good idea to check on the regulations and if the seller will include the required permits. Otherwise, your purchase may be seized at customs. Depending on the country of origin, export permits and inspections may be needed. 

When buying a non-native plant that is already in the US, it's a good idea to check whether it is classified as invasive or noxious in your state. A plant may not be considered invasive in a northern state with harsh winters, but may get out of control in a warmer state. 

Searchable lists of noxious weeds by state: https://plants.sc.egov.usda.gov/java/noxiousDriver#state

List of regulated plants and pests between states: https://nationalplantboard.org/laws-and-regulations/

I am in Zone 7B (North Alabama). I grow several fruit trees from Asia and they seem to love it here. Jujube, Asian Persimmon, Asian Pear, Asian Plums, Che, Kiwi.  I will try Pineapple Guava which I think is from Southern Brazil.
Would love to hear of some others.

These are but a few of the non-native species that have been brought to the Americas.
European/Mediterranean Grapes,
European Apples
European Pear
European Plums
European Cherry
European/Mediterranean Apricots
European Mediterranean Almonds
European Raspberry, etc, etc

But if you are talking about uncommon non-native species here are a few more:
Loquat
Flying Dragon Citrus
Goumi
Silverberry
Dwarf/Weeping Mullberry

Chinese Haw
Flowering/Asian Quince
Asian Plum/Cherry/Apricot
European Medlar
European Seaberry
Even Mediterranean pomegranate could be included.

Also, interstate regulations can come into play. California, for instance, has restrictions on certain kinds being brought from other states within the U.S.