Growing hemp in America became a federal commercial reality under the 2018 Farm Bill. Our farm in Wilmore, Kentucky has been licensed and operating since then, and the question we get most from new growers is the one in this post's title: how do you actually grow hemp? The real answer covers seed depth, transplant dates, soil pH, and what failure looks like in the field.
This guide walks through hemp cultivation start to finish: licensing, climate, soil, seed choice, planting, care, and harvest. Most of what follows is how we farm CBD hemp on our USDA Organic plot in central Kentucky. Industrial hemp grown for fiber or grain runs on a different timeline and a different planting density, and we'll flag those differences as they come up.
If you want broader context on how we farm, our USDA Organic hemp farming story covers the WHF approach.
Is Hemp Legal to Grow in the US?
Yes. Growing hemp commercially is legal across all 50 states under federal law, but you need a license. That license isn't optional, and it isn't fast.
Federal Requirements: 2018 Farm Bill
The 2018 Farm Bill removed hemp from the federal Controlled Substances Act and defined hemp as cannabis containing 0.3% Delta-9 THC or less on a dry weight basis. Above that threshold, the crop is classified as marijuana under federal law, which means a tested-hot field has to be destroyed. Every commercial hemp grower has to register either with their state department of agriculture (in states that operate USDA-approved hemp programs) or directly with the USDA Domestic Hemp Production Program.
Federal rules cover testing protocols, recordkeeping, and the destruction process if a crop exceeds the 0.3% limit. State programs add their own layers on top.
State Licensing Basics
State hemp programs vary significantly. Some states require pre-harvest testing 30 days out. Some require background checks. License fees range from a few hundred dollars in agricultural states to several thousand in states with stricter programs.
We can't tell you what your state requires. That changes year to year, and we aren't your lawyers. Consult your state department of agriculture before you order seed or break ground. Most state ag departments publish their hemp program requirements on their website with a contact line for questions.
Hemp Growing Basics: Climate, Soil, and Site Selection
Hemp is not a delicate crop, but it isn't a "throw it anywhere" crop either. The wrong site can cost you a season.
Best Climate Zones for Hemp
Hemp grows in most temperate climates with a defined frost-free growing season of at least 110 days. The historic US hemp-growing states (Kentucky, Tennessee, Wisconsin, New York, the Carolinas) all share that profile. Colorado, Oregon, and Vermont have built strong hemp programs since legalization. The plant tolerates a wide temperature range once established, but it doesn't germinate in cold soil and won't set good flower in extended drought.
For CBD hemp specifically, the goal is a long warm summer and a clean, dry harvest window in early fall. Wet harvests rot flower fast.
Soil Requirements and pH
Hemp prefers loamy, well-drained soil with a pH between 6.0 and 7.5. It will not tolerate standing water. Heavy clay can work if you amend for drainage, but sites that pond after a hard rain are not hemp ground.
Organic matter matters. We aim for 3.5% or higher in our fields. A baseline soil test before planting is worth the small lab fee. You're checking pH, organic matter, and macronutrient levels (nitrogen, phosphorus, potassium) before you make decisions about amendments. If pH is below 6.0, lime in the fall before you plan to plant. If it's above 7.5, sulfur applications can bring it down, but those changes happen slowly. Don't expect a one-season fix.
Choosing Hemp Seeds or Starts
Before you order seed, decide what you're growing for. The hemp plant you'd grow for CBD flower is genetically and structurally different from the plant you'd grow for fiber rope or grain. The cultivation plan changes too.
CBD Hemp vs. Fiber Hemp vs. Grain Hemp: Which Are You Growing?
CBD hemp is grown for the cannabinoid-rich flower. Plants are spaced widely (often 1,000 to 1,600 per acre) so each plant can branch heavily. CBD hemp is typically started indoors, hand-transplanted to the field, and hand-harvested. The labor is closer to vegetable farming than grain farming. This is what we grow at WHF.
Fiber hemp is grown densely (around 30 to 35 pounds of seed per acre, hundreds of thousands of plants) for tall, slim stalks with strong bast fibers. It's harvested with combines or specialty cutters and goes into textile, building material, and rope production.
Grain hemp is grown at moderate density for hempseed harvest, then often combined the way you'd combine wheat. Grain varieties don't usually produce CBD-rich flower.
Trying to grow CBD hemp on a fiber-density plan, or vice versa, is the fastest way to lose a season. For a deeper breakdown of this split, see our hemp fiber vs seed cultivation guide.
When ordering seed, check that the cultivar is on your state's approved list. Many states publish a Certified Variety list each year.
Starting from Seed: Germination Basics
For CBD hemp, most growers start seeds indoors in trays four to six weeks before transplant. Hemp seeds germinate at soil temperatures of 65 to 70°F. Below about 50°F, germination either fails or stalls. We use a soilless starter mix, keep humidity around 70% for the first week, and bottom-water to avoid damping off the young hemp seedlings.
Direct seeding works for fiber and grain hemp planted at higher densities, but for CBD hemp the transplant route gives much better stand uniformity and lets you cull weak seedlings before they hit the field.
Planting Hemp: A Step-by-Step Guide
Planting is where the year's plan meets the field.
Spacing and Planting Depth
Plant hemp seed at a depth of half an inch to one and a quarter inches (about 1.9 to 3.2 cm). Deeper than that, especially in heavy soil, cuts emergence rates significantly.
Spacing depends on what you're growing:
- CBD hemp: 1,000 to 1,600 plants per acre, typically a four to six foot spacing on rows that allow tractor or hand cultivation between rows.
- Fiber hemp: dense broadcast or drilled, 30 to 35 pounds of seed per acre.
- Grain hemp: roughly 25 to 30 pounds per acre on standard grain drill spacing.
Walk your field after emergence and re-seed gaps within the first week if you can. Stand uniformity affects everything downstream, especially weed pressure.
When to Plant Hemp (Timing by Region)
The simple rule: plant after the last spring frost, when soil temperatures at planting depth have warmed to at least 50°F and stay there.
In Kentucky, that usually means we transplant CBD hemp in late May or early June. Indoor starts go into trays in mid-April. We harvest in early to mid October. That gives the plants 110 to 130 days in the field, which is what most CBD cultivars need to finish.
Northern growers (Wisconsin, New York, Vermont) plant a couple weeks later and harvest a couple weeks earlier, with shorter-day cultivars selected to match. Southern growers (Georgia, Tennessee, North Carolina) can sometimes plant earlier, but heat and humidity bring different problems on the back end. Check what's actually working for licensed growers in your county before you commit to a date.
Caring for Your Hemp Crop
Once the crop is in the ground, the season's work is irrigation and feeding, with constant scouting for pests and disease.
Watering and Irrigation
Young hemp plants need consistent moisture. Established hemp is moderately drought-tolerant. The combined need across a typical CBD growing season is about 20 to 30 inches of water, with the heaviest demand in weeks two through eight after transplant.
Drip irrigation is the cleanest method for CBD hemp, especially on plastic mulch. Overhead irrigation works for fiber, but on flowering CBD hemp it can drive bud rot in the back half of the season. Whatever the method, hemp does not tolerate waterlogged soil. If your field ponds after a heavy rain, that root zone is suffocating.
Fertilization and Soil Amendments
Hemp is a heavy feeder, especially nitrogen during the vegetative phase. A general baseline for CBD hemp is 100 to 150 pounds of nitrogen per acre across the season, with phosphorus and potassium adjusted based on your soil test. Demand shifts toward potassium during flowering.
On our USDA Organic plot, we work compost into the rows pre-plant, side-dress with feather meal during vegetative growth, and use kelp and fish-based foliar feeds through flower. The certification rules out synthetic fertilizers, which means more careful planning, not lower yields.
Pest and Disease Management
Hemp's reputation for being pest-free is overblown. Real pressure points include:
- Corn earworm and budworm: the worst late-season pest for CBD hemp in the Mid-Atlantic and Southeast. Monitor flowers from week six of bloom on.
- Russet mites and broad mites: harder to spot, devastating when they take hold. Scout under a 30x loupe.
- Botrytis (bud rot) and powdery mildew: humidity-driven. Wide spacing, airflow, and pulling infected plants fast are the main defenses.
Approved organic controls include Bt for caterpillars, beneficial predators (lacewings, predatory mites) for mite pressure, and cultural controls like spacing and pruning for fungal pressure. Synthetic options exist for non-organic growers, but residue testing at harvest will rule out anything not labeled for hemp.
Harvesting Hemp: Knowing When and How
Hemp harvest timing is the single biggest decision you'll make all season.
Visual Harvest Indicators
For CBD hemp, you're watching trichome color and pistil maturity. Trichomes (the tiny resin glands on the flower) shift from clear to milky to amber as the plant matures. Most CBD cultivars are harvested when 70 to 90% of trichomes have gone milky and a small fraction have turned amber. Pistils (the white hairs on the flower) shift from white to orange-brown.
The hard constraint is the federal 0.3% Delta-9 THC limit. In most states, regulators require a pre-harvest sample 15 to 30 days before harvest. THC tends to climb as the plant finishes, so the window between "ripe enough" and "tested hot" can be short. We track this closely on our farm and pull the trigger the moment the lab and the visuals agree.
For fiber hemp, harvest at flowering before seed set, when fiber quality peaks. For grain hemp, harvest after seed set, when the seeds have hardened and moisture content drops.
Equipment and Methods
CBD hemp is hand-cut on most farms, including ours. We cut whole plants at the base, hang them upside down in a dry, ventilated barn at around 60°F and 60% relative humidity, and dry slowly over seven to fourteen days. Slow drying preserves terpenes. Fast drying scorches them.
Fiber and grain hemp use combines and balers, modified for hemp's tough fiber to reduce wrapping on rotating components. Even with modifications, hemp is hard on equipment.
After dry, CBD flower gets hand-trimmed and either jarred whole or sent to extraction. We hand-trim every batch and submit it to our third-party lab for COA testing before anything ships. If you want a closer look at the flower itself, what is hemp flower goes deeper into what we sell.
How WHF Grows Hemp in Kentucky
Our farm sits in Wilmore, Kentucky, on land we've been working since 2018. We're USDA Organic certified, which means a federal audit of our soil, our inputs, and our process every year. Not a marketing label.
We grow CBD hemp on a transplant schedule. Indoor starts begin in mid-April. Field transplant runs late May through early June, depending on the year's last frost. Hemp harvest runs from early to mid October, weather permitting. The plot is monitored on our live farm camera year-round.
A typical year on our farm:
- April: Seedling trays in the greenhouse. We track germination rates and cull weak seedlings before they get bigger.
- May: Final field prep, drip lines down, transplant week.
- June through August: Vegetative growth. Side-dressing, scouting, irrigation.
- September: Flower onset. Trichome checks start mid-month. Pre-harvest lab samples go in.
- October: Hemp harvest, hang dry, trim. Each batch gets a third-party COA before it leaves the farm.
If you want to see the flower this whole process produces, our farm-direct wholesale hemp flower guide covers what we sell and how we ship it.
Growing hemp well in America isn't complicated, but it isn't casual either. The crop rewards careful planning and punishes shortcuts. If you're starting your own program, start small and document everything. Real notes from one season beat any guide on the internet.
Disclaimer
All products contain less than 0.3% Delta-9 THC on a dry weight basis and are compliant with the 2018 US Farm Bill, or products sold on this site contain 0% THC. All our hemp derived products are U.S. grown non-intoxicating cannabinoids.
FDA Disclaimer: The statements made regarding these products have not been evaluated by the Food and Drug Administration. The efficacy of these products has not been confirmed by FDA-approved research. These products are not intended to diagnose, treat, cure or prevent any disease. These products should not be used if you are pregnant or nursing. No statements are offering medical advice. Please consult a healthcare professional before use of any of our products.
