Here’s a look at whether the climatic and geographic conditions in Virginia are suitable to the growing of industrial hemp flower.
Plant Hardiness Zone(s)
The USDA plant hardiness map for Virginia divides the state into four different zones, ranging from 5a to 8a. This spread is primarily due to the geographical variations in the state, from the eastern shore to the mountainous western region. Industrial hemp flower does best in zones ranging from 8 to 11.
A humid subtropical climate zone covers the area east of the Blue Ridge Mountains, Roanoke Valley and the southern portion of the Shenandoah Valley. Moving westwards from the mountains, the climate becomes maritime temperate and humid continental. The average annual temperature across the state is 58.75 degrees Fahrenheit. Hemp flower does well in a mild climate with a minimum average temperature of around 45 to 50 degrees Fahrenheit per year.
Length of Growing Season
On average, across the state, the growing season is about 160 days long. This marks the period between the last and first frost. Even though frost may help make the work of harvesting mature hemp plants easier, as the leaves fall off leaving the bare stalk to be harvested, it may kill or damage seedlings. Hemp plants take 120 days, on average, to grow from seedling to maturity.
Average Annual Sunlight
Virginia averages around 213 days of sunshine each year; with annual average sunlight hours exceeding 2600 hours in most parts of the state. To grow through the entire vegetative stage, hemp plants need to get more than 12 hours of sunlight each day. This means that outdoor plants must be planted with a view of meeting these requirements before the day length goes below 12 hours, thus triggering the flowering stage.
Average Annual Precipitation
Virginia is divided into 5 different climatic zones, each with its own specific average annual precipitation. Southwestern Mountain Climate Region (47.33 inches), Western Mountain Climate Region (40.74 inches), Northern Virginia Climate Region (38.29 inches), Tidewater Climate Region (41.32 inches) and the Piedmont Climate Region (43.37 inches). With much of the moisture required in the initial growth stage, an average of 25 to 30 inches of rainfall annually will support the healthy growth of hemp plants.
The state of Virginia has a mean elevation of 950 feet above sea level. The altitude rises from sea level, at the Atlantic Ocean, to 5,729 feet above sea level, at Mt. Rogers. High attitudes may have an adverse effect on the growth of high quality hemp plants. These plants should be grown at altitudes below 600 to 800 feet above sea level.
About half of the soils in Virginia — especially those in the far eastern and central regions — are acidic with a pH level of less than 5. This means that liming is necessary to make them arable. Virginia’s most fertile lands are the river plains as the rivers bring fertile, arable soil from other areas. Soil pH levels of 6 to 7.5 are necessary for the growing of premium hemp flower.
Pamunkey soil is the official state soil of Virginia. The James River is credited with bringing this high quality soil to the central and western counties of the state. The eastern part of the state has the sandiest and densest soil considered to be poor for farming. Hemp flower does best in well aerated and drained loam soils that hold moisture and nutrients well.
Some of the common pests found in the state of Virginia and known to attack hemp plants include aphids, borers and spider mites.
Obtaining A Hemp Flower Grower’s License In Virginia
Under federal law, it is illegal to grow hemp flower 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. For information on the legal status of hemp in Virginia, as well as a breakdown of the application process, click here. Read about CBD legality by state.