As part of my Python programming practice, I came up with a module and function that randomly generates 5 USDA Plant Hardiness Zones / Garden Zones.

def randomgardenzone():
    test_list = ['a', 'b']
    for i in range(1, 5+1):
        x = randint(1, 13)
        res = choice(test_list)
        print(x, res)

randomgardenzone()

For context: the US Department of Agriculture has 13 designated “zones” for the country, based on the average annual min temperature. Each zone number is 10 degrees F apart. There is a further subdivision of zones with a letter ‘a’ or ‘b’, where ‘b’ is 5 degrees F warmer than ‘a’.

These zones are useful for gardeners because we can confidently plant specimens that are hardy (cold/frost/freezing temperature tolerant) to their zone. This is why mango and bananas don’t grow in Minnesota, while they may thrive in a Floridian garden. The Minnesotan would have to have a toasty heated greenhouse in order to cultivate mango trees or bananas through their winter. (Did you know the banana plant is actually an herb, not a tree?)

I’m curious how some plants are able to be cold-hardy and resist freezing. When it gets below 32’F, the water in the plant cells wants to freeze and expand. This would rupture the cell walls and make the plant loose its structure, becoming frost damaged, mushy, and sadly, not salvageable. I heard that cold-hardy plants contain a natural antifreeze that prevents this. I’m curious how antifreeze works, and if it’s similar to what’s used in automobiles. Dianthus is an example of a common plant that is cold-hardy (you can grow them in Alaska), and in fact they need a cold season in order to thrive.

Python Things I learned:

• Use “for i in range(1, 5)”, not just “for i in (1,5)”. A simple doh!-type mistake!
• range(a, b) works like [a, b) – it is exclusive of the b value. However, randint(a, b) is inclusive of the b value.
• The “choice( )” function from the random module let’s you pick a random item from a list. This was useful to pick the zone letters ‘a’ or ‘b’, since randint( ) is only used to pick a random integer.