USDA Gardening Zone 6: Frost Dates, Locations, & Tips

Garden with snow covered green house in winter an plumm tree in the background

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When you're planting your garden, you want to give your plants the best chance of thriving. Some places are too cold for certain plants, and others are too warm. So how do you know what's just right for your region? Check out the USDA hardiness zones, which are determined by how cold it gets in the winter months.

USDA hardiness zone 6 is broken up into two subzones — zone 6a and zone 6b. It runs in a swath through the center of the country from Eastern Washington down through parts of the Mountain and Southwestern states, into the Midwest, and into the Northeast as far as parts of New Hampshire. If you live in this band, you'll probably have good luck with Zone 6 plants. Here's what you need to know about gardening in USDA plant hardiness zones 6a and 6b.

Zone 6 Hardiness Temperatures

Winter vegetable garden covered in snow with wooden raised beds,

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The temperatures for each zone are separated by a difference of 10°F. Zone 6 is 10°F colder than Zone 7, and Zone 5 is 10° colder than Zone 6, and so on.

Subset Zone Temperatures Zone 6a and Zone 6b

Each gardening zone is divided into two subsets; zone 6 subsets are 6a and 6b. Each subzone is separated by 5°F. That means for Zone 6:

Zone 6: This zone has a minimum average cold temperature of -10° to 0°F.
Zone 6a: This subzone has a minimum average cold temperature of -10° to -5°F.
Zone 6b: This subzone has a minimum average cold temperature of -5°F to 0°F.

The average minimum temperature for the winter months determines the zone and subset ranges. The temperatures don't always fall in this range since colder temperatures can occur.

Zone 6 States

USDA Plant Hardiness Zone Map - By USDA-ARS and Oregon State University (OSU)

By USDA-ARS and Oregon State University (OSU) via Wikimedia Commons

Because the climate can vary throughout a state, each state has more than one hardiness zone. For example, Alaska has zones 1 to 8. If you need specific information about the hardiness zone where you live, the USDA plant hardiness map can show you exactly what's in zones 6a and 6b. Our chart can also give you a general idea, and the above map can help you zero in on your area.

**Zone 6 States**
State	Zone 6a or 6b	Notes
Southern Alaska	6a & 6b	Mostly 6A
Arizona	6a & 6b	Northern, Eastern (see map)
Arkansas	Mostly 6b	Northern
California	Mostly 6a	Central Eastern to North Eastern (see map)
Western Colorado	Mostly 6a	(see map)
Southeastern Colorado	Mostly 6a	6b in the very Southeastern tip (see map)
Connecticut	6b	Small areas of 6a in the Northwest
District of Columbia	6b
Idaho	6a & 6b	6a in panhandle Mostly 6b in Southern ID
Illinois	6a & 6b	6a Central IL 6b Southern (7a in the very south)
Indiana	6a & 6b	6a Northern & Central 6b Southern
Iowa	6a	Small area in the Southeastern corner
Kansas	6a & 6b	6a in Northwest corner 6b from Southwest to Eastern Central
Kentucky	6a & 6b	6a in Northeastern tip 6b rest of state
Maryland	6b	Small area in the North
Massachusetts	6a & 6b	6a South Central 6b East
Michigan	6a	South and Central Bordering Lake Michigan
Missouri	6a & 6b	6a North (except on IA border) 6b Central
Montana	6a	Northwestern corner
Nevada	6a & 6b	Central NV
New Hampshire	6a	Southern
New Jersey	6b	Northwestern corner
New Mexico	6a & 6b	Throughout state (see map)
New York	6a & 6b	Throughout state (see map)
Ohio	6a & 6b	6a Western and Northeastern 6b rest of state
Oklahoma	6b	Panhandle
Oregon	6a & 6b	Central & Eastern (see map)
Pennsylvania	6a & 6b	Throughout state (see map)
Rhode Island	6b	Entire state
Texas	6b	Very northwestern tip
Rhode Island	Tennessee	Texas
Utah	6a & 6b	See map
Washington	6a & 6b	Central & Eastern (see map)
West Virginia	6b	Eastern

Zone 6 Growing Tips

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Use the hardiness zone guide to decide which plants grow best in your region. Most zones have a variety of trees and plants that thrive in Zones 6a and 6b.

Vegetables

In Zone 6, start seeds for transplants indoors six weeks before the last frost date. These include tomato, eggplant, pepper, and other easy-to-transplant plants. Direct-sow vegetables, such as beans, cabbage, corn, cucumber, squash, and others can be planted on or around May 1.

Quick Tip

Check the maturation days on the seed packet. This is the number of days it takes from the time you sow the seeds to the time the vegetable is ready for harvesting.

Cold-Hardy Fruit and Nut Trees

You can grow cold-hardy fruit trees and nut trees in Zone 6, including:

Apple trees, such as Honeycrisp, Gala, McIntosh, and others
Most European pears, such as Bartlett and Conference
Several peach tree varieties, such as Reliance, Madison, and others
Plums, cherries, blackberries, and blueberries
Walnut, pecan, pine nut, chestnut, and other trees

Perennial Flowers

You can grow lots of flowers, including begonia, calla lily, dahlia, and gladiola.

Shrubs

For shrubs, you can choose azalea, buddleia, clematis, hydrangea, and rhododendron.

Frost Dates for Zone 6

Since much of planting involves looking at the first and last frost dates, having an idea of when that is for your zone can be helpful. These aren't exact, but they give you a good idea of when it's safe to plant.

Last frost date: April 1 to April 21
First frost date: October 17 to 31

You can download a current frost date app that will give precise frost date information specific to your ZIP code.

Things Zone Designations Don't Include

The USDA Hardiness Zone Map is calculated using the average low temperatures for a specific zone. These guidelines are designed to assist you in selecting plants and trees that can survive the winter months in your zone. The zone map doesn't take into consideration other growing factors, such as droughts, rainfall, microclimates, soil fertility, and unusual weather patterns.

Gardening in Zones 6a and 6b

The growing season for Zone 6 is considered a medium-long time frame for growing most vegetables, fruits, shrubbery, flowers, and other plants. Seed and plant companies always include zone information on seed packets for your convenience and successful planting.