Portsmouth's Hardiness Zone

Our records indicate the United States Department of Agriculture has given Portsmouth a growing zone designation of 6a. Sometimes also called the planting zone or hardiness zone, this zone number gives you an idea of what plants can and cannot grow in Portsmouth's climate. If you are looking for plants suitable for growing in the Portsmouth area, head on over to our page on plants that grow well in Portsmouth, NH.

Reusable Grow Bags

Breathable fabric grow bags that promote healthy root growth for your vegetables and fruits.

Rustic Iron Garden Trellis

Sturdy trellis for supporting climbing plants and vines.

Stainless Steel Garden Tool Set

Complete garden tool set with heavy-duty stainless steel tools for all your gardening needs.

Seed Starting Trays

Perfect for starting seeds indoors before transplanting to your garden.

Self Watering Plant Pots

Innovative pots that maintain optimal moisture levels.

Understanding your growing zone is very important because it is a measure of the lowest temperature that a plant can survive, helping you to decide what plants would grow best in your particular climate. Since Portsmouth is in growing zone 6a this means that plants there can survive temperatures as low as 10 to 15 degrees Fahrenheit. Plants chosen for Portsmouth's climate should be chosen with this in mind or plants should be moved inside to keep their core temperature in the right range if necessary.

USDA Growing Zone: 6a

Zip Codes: 03801, 03802, 03803, 03804

Longitude: -70.7826

Latitude: 43.058

Lowest Avg Temperatures (F): -10 to -5