Hemp is a controversial plant because it's often confused with marijuana. While hemp and marijuana come from the same plant family, they're two distinct species. Farmers raise marijuana for its psychoactive components, while hemp is used for food, fuel, biomaterials, paper, clothing, and more.
The difference between the two is in the amount of tetrahydrocannabinol (THC) they contain. Marijuana has higher levels of this compound which causes the sensation of euphoria by stimulating the brain to release dopamine.
Hemp is growing in popularity because it can be used to make many products including rope, clothing, shampoo, foods, and supplements like CBD oil. Thirty countries around the world grow and export industrial hemp products. China currently produces 20% percent of the worlds hemp supply. These days, many State Departments of Agriculture are promoting hemp as a profitable crop for farmers.
Whether you want to grow hemp for your own home use or you're interested in selling hemp products, this guide will get you on your way.
Is it Legal?
The 2014 Farm Bill defined hemp as the cultivar Cannabis sativa L. Plants must have no more than .03% delta-9 tetrahydrocannabinol (TCH).
In December 2018, President Trump signed the 2018 Farm Bill which had a provision that legalizes domestic hemp growth and allows industrial growers to obtain a license for production. The goal of the bill is to encourage the sale of American-grownCBD oil and hemp seeds.
Buying Hemp Seeds
Since hemp was only recently legalized, seeds are a bit hard to come by. That will change in the future, but for now, there are a few suppliers that you can get seeds from.
- Seeds From
Hemplogic, a leader in the hemp industry. You must contact them for prices and to see if they sell to your area.
- ColoradoByDesign has non-feminized varieties available.
- Seeds from bulkhempwarehouse.com carry unnamed varieties for $10 per ounce. This may be good for the person who wants to experiment a little in their garden.
Seeds that are “feminized” have been genetically altered to produce more female plants and don't require cross-pollination. These plants may be hybrids or they may be a GMO crop. Do your research if you plan to have organic production. Genetically modified seeds aren't an option for sustainable farmers and gardeners.
Purchasing seeds may still require an application until companies and regulations adapt. You can contact your state DOA for more information. Also, be prepared that hemp seeds are expensive compared to other crops.
Depending on what you want to use your hemp for, you'll want to pay attention to the level of cannabidiol (CBD) and cannabinol (CBN) in the seeds.
This variety includes non-feminized regular seeds. It has a CBD level of 12-14% and a CBN level of 1.4%. Flowering time is 9-11 weeks. THC level is below .03%.
This variety is monoecious (meaning it has both male and female seeds). It's early maturing and rich in fiber. The THC level is below 0.2%. The ideal grain harvest date is August 25. In northern regions, you can grow this type as a grain and for dual-purpose use.
Z2 features non-feminized seeds. It has a CBD level of 6-7.38% and a THC level of less than .03%. Flowering time is 8-10 weeks.
This Northern California variety is a non-feminized strain that has a high flower yield with a delicious flavor. The oil is also flavorful. It can handle some snow and survives in even the worst soil. It has a CBD level of 10-12% and is ready for harvest in late October.
How to Plant Hemp
Where to Grow Hemp
Hemp grows just about everywhere in the U.S. as an annual, except in extreme desert conditions.
When to Plant
Start seeds indoors four weeks before the last frost date in your zone. Transplant seedlings after danger of frost when the soil has warmed to above 50°F.
Hemp prefers a soil pH of 7.0-7.5. Test your soil in the fall, and if your pH is too low, you can add lime to the area.
Hemp grows best in loam with lots of compost. It has fibrous roots and doesn't like compacted soil. Soil should drain well. However, overly sandy soil isn't ideal because it doesn't hold water and nutrients as well, which means a lower quality product.
Ideally, hemp should have fertile soil that is rich in organic matter, with a
Hemp plants prefer a warm growing environment with plenty of moisture. They do well in southern and western states. Plants need full sun to be productive.
Hemp is a fast-growing plant that gets tall – some varieties up to 16 feet. It can grow three inches per day in the right growing conditions.
Spacing depends on what the hemp will be used for. When planting to harvest fiber, it's best to space plants at 12-inches apart. When planting for seed production the plants should be closer to encourage branching. About 7-inches of space is ideal.
Hemp can be direct seeded. Seedbeds should be tilled and smoothed out with a rake so that the soil is level and free of clods.
Seeds should be planted at a depth of one inch. You can use a grain drill or a standard planter.
Caring for Hemp
Hemp grows similar to corn and has high nutrition and water needs. Like corn, it cross-pollinates via the wind.
Hemp is dioecious. Dioecious plants may be male or female – like asparagus and spinach. Males do not produce seeds but are necessary for pollination.
People in western states may need to provide additional irrigation. Hemp has high water needs in early development, though it can handle some drought as it gets older. Good root development depends on good irrigation so that the roots can penetrate the soil and stabilize the plants.
Hemp has high nitrogen and phosphorus needs and does not like excess calcium.
Hemp Problems and Solutions
Hemp is susceptible to weeds. In my Kentucky area that means common field weeds such as pigweed, crabgrass, and Johnston grass. Regular weeding is imperative so that the plants establish good roots and can grow quickly.
Growing hemp seedlings are susceptible to damping off. Use sterilized soil and clean your planting tools to prevent damping off. Also, make sure plants have plenty of circulation.
Bacterial and Fungal Leaf Spot
Leaf spot, as the name indicates, shows up as brown spots on leaves. To prevent leaf spot, make sure to not crowd your hemp seedlings and allow for plenty of air circulation.
You can also spray plants, but guidelines have not been set for spraying hemp crops. Opt for organic pesticides and herbicides
Rootworms lay their eggs in the soil and the emerging larvae feed on the roots of growing hemp. Till soil in the fall to expose eggs and spray with an organic pesticide.
Corn borers lay eggs on the underside of leaves and the moths emerge in May or June. Use pheromone traps and encourage beneficial garden predators.
Blister beetles carry a toxic agent that can be harmful to humans and livestock, as well as plants. You can hand pick them off of plants (be sure to wear gloves) and spread diatomaceous earth around your garden.
Harvesting Hemp Seed
One reason for growing hemp is so you can harvest the seed. Seeds are used to make hemp oil and are a nutritious snack. If you're looking for seed production you will need to plant a variety that is composed of mainly female plants.
Hemp is a short day plant. This means that hemp will develop flowers when the daylight is less than 12 hours. Seeds typically ripen about six weeks after the plant flowers. Harvesting the seeds in the proper window is important. The plant spreads its seeds by shattering, which means ripened seeds will fall to the ground.
The key for the gardener is to harvest when the seeds are ripe but before the mother plant disperses them. After harvesting the seeds store them in a cool dry place. They will keep for up to one year.
Harvesting Hemp Fiber
You can also grow hemp for fiber. Hemp is popular for clothing and textiles because it's strong and wears well.
Fiber is extracted from the stalk of the plant. Retting is a process where water and bacteria are used to break down the stalks. When the stalks are supple the fibers can be extracted. The fiber is then rendered so that it can be made into cloth.
Many growing guides for hemp don't consider the roots, which is a shame, because the roots of cannabis varieties have a long tradition in medicine.
First recorded in Ancient Roman times, they've been used to treat inflammation, joint pain, and gout. Scientists have studied compounds in the roots which support these claims.
Dried cannabis roots can be mixed with olive oil to make a soothing topical ointment.
Get Growing Hemp
Thanks to its new legal status, hemp is poised to be the new wonder crop in American agriculture. Many states hope that it will financially replace tobacco as a crop that has a substantial profit margin for farmers.
Hemp products are popular because they have a low environmental impact. They can be recycled and are biodegradable, giving them a competitive market edge.