I live in zone 6a, but as you can see in the map above, zone 6a stretches from the west coast to the east coast. These areas are vastly different from each other. Indiana’s climate is much different than Arizona, but both states have 6a hardiness zones. The plant map you see above, refers solely on the average winter low temperature in your area. If you’re growing annual vegetables, this isn’t nearly as important as how long your growing season is.
If I don’t look at zone what do I look at?
I like to refer to Farmer’s Almanac. Simply input your zip code then it will tell you your estimated first and last frost dates.
As you can see my growing season is 167 days long. I have a fairly long growing season. Large tomatoes can take about 3 to 4 months to start producing any fruit (around 120 days to start producing). This means not every area has a long enough growing season to grow tomatoes outdoors. If you want to know if you have enough time in your season to grow a vegetable: look up that plant, see how long it takes to grow, and compare it to how long your season is.
What is the plant hardiness map for?
The map above simply refers to perennial plants like flowers, shrubs, and trees. In order for those plants to come back in the spring, they must be able to survive the lowest winter temperature in your zone.
Eager Gardener 