The Plant Hardiness Zone Myth

What does the hardiness of a plant mean?
Why are hardiness zones important?
How do hardiness zones work?
What are plant hardiness zones and why are they important for growing plants?
What is the most hardy plant?
What is the lowest temperature plants can tolerate?
What is the difference between zone 9a and 9b?
What is the difference between hardiness zone and climate zone?
How do you read a hardiness zone?
When can I plant in Zone 6b?
When can I plant in Zone 7b?
What is growing zone 6b?

What does the hardiness of a plant mean?

Hardiness of plants describes their ability to survive adverse growing conditions. ... Tender plants are those killed by freezing temperatures, while hardy plants survive freezing—at least down to certain temperatures, depending on the plant.

Why are hardiness zones important?

Why is it important for gardeners to know their hardiness zones? Knowing your zone is the key to choosing plants that can survive and thrive in your particular area. Choosing plants that are not hardy in your zone can lead to frustration, disappointment and unnecessary expense.

How do hardiness zones work?

What Is the USDA Plant Hardiness Zone Map? ... This map divides the United States into 11 separate zones (each of which are then divided into a and b). Each zone is 10°F warmer (or colder) in an average winter than the adjacent zone. The lower the zone number, the colder the region.

What are plant hardiness zones and why are they important for growing plants?

In order to help growers find the best places to grow, the USDA has devised a map that divides North America into eleven separate planting zones. These zones are called Plant Hardiness Zones and each one is an average of ten degrees warmer or colder in the winter than the zone adjacent to it.

What is the most hardy plant?

Purple Saxifrage, the Hardiest Plant in the World

With its pretty purple flowers carpeting the tundra in spring, purple saxifrage looks a bit delicate. It certainly doesn't look like it could take much of a beating. Yet it's common throughout the Arctic and grows further north than any other flowering plant.

What is the lowest temperature plants can tolerate?

Tropical plants have differing low-temperature thresholds. Some keel over when temps fall to 40°F; others crumble at 35°F. Other plants are just hardy by nature and can withstand temperatures as low as 18-20°F. To find the threshold for your plants, search garden books and online resources.

What is the difference between zone 9a and 9b?

Subset Zone Temperatures

The Zone 9 subsets are Zone 9a and Zone 9b. ... Zone 9: The minimum average temperature range is 20°F to 30°F. Zone 9a: The minimum average temperature range is 20°F to 25° F. Zone 9b: The minimum average temperature range is 25°F to 30°F.

What is the difference between hardiness zone and climate zone?

Unlike the U.S.D.A. map which tells you only where a plant may survive the winter, the Climate Zones map shows where that plant will thrive year-round.

How do you read a hardiness zone?

The USDA Plant Hardiness Zone Map was created by the USDA to help growers and gardeners understand which plants are most likely to thrive in a specific location. The map is based on the average annual minimum winter temperature, divided into 10-degree F zones.

When can I plant in Zone 6b?

According to Sunset, zone 6 vegetable planting runs from mid-March after the last frost through mid-November. In both cases, it's important to remember that these are guidelines and winter or summer can come earlier or last longer than is typical.

When can I plant in Zone 7b?

Zone 7. In zone 7, cool-weather vegetables can usually be planted outdoors in early February. These crops include beets, broccoli, cabbage, carrots, lettuce, onions, peas, potatoes, radishes, spinach, turnips, kale and collards. Plant corn in March.

What is growing zone 6b?

Subset Zone Temperatures

Each gardening zone is divided into two subsets; zone 6 subsets are 6a and 6b. ... Zone 6: This zone has a minimum average of temperatures of -10° to 0°F. Zone 6a: This subzone has a minimum average temperature of -10° to -5° F. Zone 6b: This subzone has a minimum average temperature of -5° to 0°F.