Growing Hemp in New Hampshire

Begin Your Hemp Journey

A Guide to Growing Hemp in New Hampshire


New Hampshire enjoys a loamy soil that is very conducive to gardening. With a changeable climate, the summers are short enjoying the hottest month in July at approximately 82 degrees Fahrenheit and winters are cold and snowy. Gardening seasons are short here and without a greenhouse, chances are garden crops won’t come to full maturity unless they are specifically designed for shorter growing seasons. 

Plant Hardiness Zone(s) 

New Hampshire is split into six different hardiness zones and most of them have very low potential temperatures. The plant hardiness zones in New Hampshire are 4a, 5a, 6a, 3b, 4b, and 5b. The zone with the lowest potential temperature is 3b and it is located at the northernmost tip of the state. It can have extreme minimum temperatures as low as 35 degrees Fahrenheit. Much of the state is divided between zones 5b and 5a, which have extreme low temperatures of -15 and -20 degrees Fahrenheit respectively. While hemp can survive days or weeks at extreme low temperatures in 5a and 5b, it would be very difficult to thrive in the northern 3b zone.

Thermal Profile

The AHS heat zones in New Hampshire range from 1 to 3. A heat zone of 1 indicates that the region experiences less than one day of heat above 86 degrees each year. The warmest areas of the stay may experience anywhere between 7 and 14 “heat days” each year. Overall, this does not pose a problem for the growth of hemp. It is the potentially low temperatures that will be difficult to work with.

Length of Growing Season

New Hampshire has a very short growing seasons across the state primarily because of its low average temperatures. Many growers get a jump on the growing seasons by starting their seeds indoors and then moving them outside when the temperature is right. New Hampshire has an average of 135 days between the last frost and the first frost.

Average Annual Sunlight

There is an average of 2,519 hours of sunlight each year in New Hampshire. A clear day is any day where the cloud coverage is less than thirty percent. New Hampshire has an annual average of 90 clear days each year. That number does decrease as you get closer to the mountainous region of the state. For example, near Mt. Washington there are less than 45 clear days each year.

Average Annual Precipitation 

The average rainfall in New Hampshire is lower than many of the surrounding regions. There was an average annual rainfall of 40.69 inches between the years of 1981 and 2010. However, the average annual snowfall was much higher at 61 inches. Hemp requires between 10 and 13 inches of rainfall to grow in optimal conditions. In theory, this should be obtainable during the growing season as long as early soil moisture is properly utilized.

Surface Elevation

New Hampshire has significant elevation variations across the state. Land near the Atlantic Ocean generally has the lowest elevation. Elevation increases the further north and west you travel. The highest point in the state is Mt. Washington, which reaches a total of 6,288 feet above sea level.

Soil pH

The high rock content in New Hampshire has led to very acidic soil. Hemp grows best with the pH level is above 6.0. You may need to add limestone to the soil to increase the pH level and reduce acidity. 

Soil Composition

Much of the soil in the region was carried to its current location by glaciers thousands of years ago. This has created very shallow and acidic soil that contains very few organic compounds. Unfortunately, this can make growing plants of any type difficult. Growing hemp in optimal conditions will require treating and properly cultivating the soil.

Notable Pests

Several pests can be problematic in New Hampshire, though they are easily dealt with. The most common in the region include beetles, stink bugs, and ash borers. One of the most common diseases in New Hampshire is the boxwood blight, but luckily this blight is not a problem for hemp plants.

Obtaining A Hemp Grower’s License In New Hampshire

Under federal law, it is illegal to grow hemp anywhere in the United States without first obtaining a grower’s license from the appropriate regulatory body for the state in which the interested party intends to plant the crop. View our breakdown of the 2018 Farm Bill for more information on the legal status of hemp in New Hampshire, as well as a breakdown of the application process.


Program Name Program Type Resources
New Hampshire Pilot Department of Agriculture, Markets, and Food

Vote Hemp (New Hampshire)

How To Start A Commercial Grow Operation In New Hampshire