Planting Zones: New Hampshire Hardiness Map

USDA New Hampshire Hardiness Zones: 3b, 4a, 4b, 5a, 5b, 6a

New Hampshire Plant Hardiness Zone Map

New Hampshire, otherwise known as the Granite State, is a small farming state. According to the New Hampshire Department of Agriculture, Markets, and Food, there are roughly 4,400 working farms in the state.

Although the number of New Hampshire’s farms is relatively low compared to other states, it’s climate is still considered a prime growing condition for many plants. New Hampshire is known to produce plenty of apples and sweet corn.

The climate in New Hampshire is classified as a humid continental climate and if you live or work in there, you know the summers are warm and humid, but the winters can be long and snowy.

The warm summers and snowy winters classify New Hampshire into six different planting zones. The planting zones of New Hampshire are 3b, 4a, 4b, 5a, 5b, and 6a.

New Hampshire Planting Zone – A Quick Overview

  • The 3b growing zone is a relatively small portion of the state. If you live in the far north of the state, such as in Colebrook or parts of Coos County, you likely live in the 3b planting zone.
  • The 4a planting zone is also found in the most northern section of New Hampshire. Lancaster is considered the 4a planting zone.
  • The area surrounding Littleton is classified as the 4b planting zone.
  • The middle section of New Hampshire, including the area of Hanover and most of Carroll County, is considered the 5a planting zone.
  • You’ll find the 5b planting zone in the lower half of the state. Concord and Peterborough are considered 5b.
  • The 6a planting zone is in the southeastern portion of the state. Portsmouth is classified as 6a. A small area in Cheshire and Sullivan Counties is also considered 6a.

Using the New Hampshire Growing Zones Map 

Although the number of working farms in New Hampshire is relatively small, that does not mean the state is not suitable for growing vegetables or flowers. It is entirely possible to produce a thriving and bountiful garden!

Before choosing plants, your garden space will flourish if you consider your growing zone. Growing zones are sometimes referred to as planting zones, plant hardiness zones, or gardening zones.

In 2012, the USDA created the USDA Plant Hardiness Zone Map. This helpful map is color-coded by plant hardiness zones. A different color represents each planting zone in the United States. Relative minimum temperatures determine planting zones.

It is helpful to know which planting zone your garden space is located because many nurseries reference plant hardiness zones on plant information tags. Knowing your planting zone will save you from disappointment and frustration. You’ll be able to choose the appropriate plants for your garden.

Finding out your planting zone is simple. Access the USDA Plant Hardiness Zone Map. After opening the map, click on the state of New Hampshire. When you click on the state, you’ll see a general overview of New Hampshire’s gardening zones.

Enter your address and zip code if the general overview is not specific enough for you or you’re having trouble deciding which planting zone your garden is based on the map’s colors. Entering your address and zip code will give you the most accurate information.

Explore Our Complete US Hardiness Zone Map

Knowing your growing zone is the first step in choosing the right plants. Before you make a plant purchase, consider the micro-climate of your garden site. Many elements affect the micro-climate of an area.

If your garden is located near a body of water, evaporation rates, humidity, and dew may affect the micro-climate. Some plants may thrive in a moist environment; others may not. Consider these factors, too, before choosing your plants.

New Hampshire: The Granite State

New Hampshire’s growing season lasts anywhere between 130 days and 150 days of the year. Typically, you can begin planting outdoors after the middle of May to the first week of June, depending on your location. Be sure to wait until after the last frost date before planting, though, or you may plant too early and damage your plants.

Sweet corn is not the only crop you can grow in your New Hampshire garden. Think about planting cabbage, parsnips, or asparagus if you love fresh vegetables. Or consider beets or peppers.

If you’re not much of a vegetable gardener but love to grow flowers, the Black Forest Nursery in Boscawen, New Hampshire, suggests growing petunias, Fire Spinner Ice Plants, or peonies. Oak trees, maple trees, and crabapple trees make a great addition to any landscape.

Trees to Plant in New Hampshire

Photo of author

Fern Berg - Founder

Expert Gardener & Horticulturist in Training

Fern has planted and currently cares for over 100 different native and exotic fruit, nut, and ornamental trees. She also cultivates an extensive vegetable garden, several flower gardens and cares for an ever-growing happy family of indoor plants. Fern has a special interest in biodynamic farming, food production and closed loop agriculture. Fern founded Tree Vitalize to help guide others with an interest in tree planting, identification and care.