Hemp Farming

Embarking on the journey of hemp farming is not just a commitment to a crop; it's a pledge to sustainable agriculture and a deep understanding of a plant with vast potential. Whether you're a seasoned farmer exploring new avenues or a newcomer intrigued by the world of hemp, this guide is your compass to navigating the policies, processes, and best practices of cultivating hemp.

The Growing Process

  • Crop Establishment

    The optimal drilling period for hemp is between late April and mid-May.

    A clean seedbed with adequate moisture and warmth are important.

    Hemp can be grown organically with all of the crops nutrient requirements being supplied by the soil. Previously applied FYM/compost or incorporated over-winter cover crops will be beneficial.

    Grown conventionally, a starter fertiliser can be applied at drilling plus up to 125kgN/ha after crop emergence.

    Growing

    Hemp can be grown without any pesticides or herbicides in the UK.

    Hemp is very competitive at suppressing weeds at an early stage and once the crop canopy is complete, later weed growth is minimal. There are no current pests of hemp in the UK.

  • Hemp is typically harvested between August and October, with timing dependent on seed variety and flowering stages.

    Harvesting the crop for fibre involves cutting the crop at the base of the plant. The cut crop then undergoes a 4-6 week retting (conditioning) process on the soil before baling.

    For a seed crop, a conventional combine harvester is used. Speed, header height and drum speed is adjusted to crop conditions.

    In compliance with Home Office regulations, only the hemp seed or stalk may be harvested, while all other plant parts must be destroyed on-site.

  • There are a variety of options of Hemp seed which can be grown in the UK.

    First you need to decide what you are growing for; seed, fibre, or seed and fibre. At present we are not allowed to grow for flower or leaf in the UK.

    Once you have determined the crop then check out the EU Common Catalogue of Plant Varieties; EU Plant Variety Database, which gives you the list of legal hemp seeds available under 0.2% THC

  • Hemp is a versatile crop which has the ability of adapting to its climatic environment, growing from Siberia to South Africa! Ideally, well drained, loamy soil is most beneficial. But the deep tap roots are also useful for improving the quality of land.

    The BHA is facilitating domestic data collation in order to highlight the positive impact on soil health to present tangible evidence across a variety of soil types.

    If you are growing hemp, please do contribute to this database as the information is useful to develop agronomic knowledge in the UK and Ireland.

Home Office License

Cannabis is categorised as a Class B controlled substance, making it illegal to supply, produce, or import without a valid Home Office licence. The Home Office (HO) Policy outlines that  licences may be granted, for the cultivation of industrial hemp with a low Tetrahydrocannabinol (THC) content.

THC must be below 0.02% and only the non-controlled parts of the plant can be used under this policy.

Home Office licences are typically valid for three growing seasons, equating to a maximum validity period of three years.

You can Apply for a HO license Here

Hemp farming is the cultivation of Cannabis sativa plants specifically grown for their industrial uses rather than for recreational or medicinal purposes.

Pre-Planting

SITE SELECTION

Although hemp can grow on marginal land with minimal input, it flourishes in high-quality soil with proper agronomic management. The choice of site should align with your cultivation objectives—whether that’s making use of marginal fields or remediating contaminated land. This guide outlines the ideal conditions for successful industrial hemp cultivation.

WATER AVAILABILITY

Hemp requires consistently high moisture levels throughout its growing season. Sufficient soil moisture is essential for seed germination, and water demand is particularly high during the first six weeks as seedlings establish. Once mature, hemp develops deep taproots (reaching 2–3 metres depending on soil conditions), which improve its drought tolerance. However, extended periods of drought can lead to early maturation and reduced growth. Ideally, hemp needs between 630 and 750 mm of annual rainfall, with yield being significantly affected by rainfall levels in June and July when moisture is crucial for vegetative growth. Water requirements vary depending on cultivar, environmental conditions, and management practices.

PHOTOPERIOD

As a short-day plant, hemp's growth and productivity are strongly influenced by day length. The transition from the vegetative stage to flowering is determined by both day length and variety. Some hemp cultivars flower regardless of daylight duration, while others require shorter days to trigger flowering.

SUITABLE LAND AREA

Like all crops, hemp benefits from economies of scale—the larger the cultivated area, the more cost-effective production becomes. However, smaller plots can still be viable depending on the intended purpose of cultivation. Hemp is particularly effective for soil remediation, making it a suitable option for contaminated or marginal land, though lower yields should be expected. When integrated into a crop rotation plan, hemp can improve soil health for future crops. Unlike many energy crops, hemp is not a perennial, so it is advisable to begin with a small trial plot in the first year to develop expertise before expanding cultivation.

SUITABLE SOILS

Hemp thrives in well-drained, aerated soils with a silt/loam texture—ideally composed of around 40% sand, 40% silt, and 20% clay. A good water-holding capacity is essential for healthy growth. While hemp can tolerate a pH range of 5.0 to 7.5, the optimal range is between 6.0 and 6.5, making acidic soils unsuitable. Additionally, as hemp has a natural ability to absorb heavy metals, sites with high contamination—such as former waste areas or land affected by industrial pollution—should be avoided, particularly if the crop is intended for human consumption.

TEMPERATURE

Temperature plays a crucial role in hemp cultivation, influencing growth at various stages. While hemp thrives in temperate climates, it is adaptable to different environments. The ideal germination temperature in field conditions ranges from 13.5 to 18.5°C, although it can still germinate at lower temperatures. Excessive heat can hinder germination, particularly under stress conditions. Young seedlings (with 8–10 leaves) can withstand temperatures as low as -5°C, while optimal growth occurs when daily average air temperatures range between 16 and 27°C.

SITE ACCESS

Hemp is typically harvested using modified standard farming machinery, so hard tracks or well-maintained access routes are necessary to facilitate field entry and machinery movement.

LOCATION IN THE LANDSCAPE

The height of hemp plants varies depending on the cultivar, typically ranging from 1.0 to 3.5 metres. Most fibre cultivars reach around 2.0 metres—comparable to maize—while seed-bearing varieties tend to grow to chest or shoulder height. Visually, hemp resembles other arable crops and is unlikely to significantly alter the local landscape. However, regulations vary by country, and restrictions may apply to cultivating hemp near roads, public rights of way, or schools.

Site Preparation

Pesticide Use

At present, no pesticides are authorised for use on hemp in the UK and Ireland. This is due to hemp’s relatively recent reintroduction into modern agriculture, as well as its rapid growth and natural competitiveness against weeds. However, to maximise yield potential, careful site preparation is essential.

Soil Testing and Management

Soil testing should be conducted before planting. Key indicators such as pH, Soil Nitrogen Supply (SNS), phosphorus (P), potassium (K), and magnesium (Mg) should be assessed and adjusted as necessary during site preparation. Several companies provide soil testing services, offering detailed analysis and even field-specific insights to support targeted nutrient application.

Based on test results, nutrients or lime can be applied to optimise soil conditions for hemp growth. However, excessive fertiliser use should be avoided, as it may encourage weed competition during the early stages.

Soil microbial biomass and community profiling can also be beneficial. Mycorrhizal fungi, for example, aid hemp establishment and enhance its resilience in contaminated or stressful conditions. Testing can help determine whether soil supplements may be necessary.

Additionally, baseline soil analysis can be useful in assessing soil carbon stores.

For further information, visit: AHDB Soil and Forage Testing Companies.

Fertilisation

Hemp requires precise nutrient management, as both over- and under-fertilisation can lead to self-thinning and reduced yields. The total recommended NPK application rates for hemp are:

  • 110 kg N/ha (Nitrogen)

  • 80 kg P/ha (Phosphorus)

  • 140 kg K/ha (Potassium)

The following sections outline the requirements for nitrogen, phosphorus, and potassium in more detail. It is strongly advised to conduct soil tests before applying fertiliser, as existing soil nutrient levels may already be sufficient.

  • Hemp has a nitrogen offtake of approximately 160 kg N/ha for biomass and 40 kg N/ha for seed, totalling 200 kg N/ha. Ensuring sufficient nitrogen supply is crucial. A low application rate (e.g., 80 kg N/ha) can stunt growth, while excessive nitrogen (e.g., 200 kg N/ha) causes plants to compete for light, reducing plant density and yield. An application rate of 110-150 kg N/ha is recommended, based on local soil conditions and nitrogen deposition rates.

    Nitrogen application before planting is generally as effective as a split application. Split application—where fertiliser is applied in stages—reduces risks such as nutrient leaching due to adverse weather or plant stress. The recommended split application is:

    • 70% at planting

    • 30% during elongation/rapid growth phase

  • Phosphorus is vital at all growth stages but is particularly important during early development, as it strengthens plants and enhances pest resistance. As the crop matures, phosphorus uptake gradually increases. Total phosphorus uptake varies between 25-67 kg P/ha, depending on variety and yield. Recommended application rates range from 30-80 kg P/ha, with applications tailored to soil test results to avoid unnecessary stress on the plants.

  • While potassium has less impact on hemp yield, it is essential for fibre quality. Hemp absorbs large quantities of potassium, with total uptake averaging 211 kg K/ha. Recommended application rates range from 140-175 kg K/ha, depending on soil reserves and expected yields.

  • Calcium (Ca), magnesium (Mg), sulphur (S), copper (Cu), manganese (Mn), and boron (B) all contribute to healthy hemp development. In particular, calcium, magnesium, and sulphur play critical roles. Soil tests will indicate whether supplementation is necessary.

Digestate Use

Applying liquid phase digestate (LPD) and solid phase digestate (SPD) in a split application has been shown to be an effective alternative to mineral fertilisers. Application rates should align with the recommended NPK levels above. SPD provides a prolonged nutrient release, reducing environmental impact compared to traditional fertilisers.

Ploughing and Cultivation

Proper seedbed preparation is essential for successful hemp cultivation, as hemp is highly sensitive to soil structure. The ideal approach is to prepare the soil as one would for sugar beet or spring wheat.

Where permitted, autumn ploughing to a depth of 20 cm is advised, followed by cultivation using a rotavator or power harrow to create a stale seedbed. If winter fallowing is not possible, ploughing and cultivation should be carried out as soon as regulations and weather conditions allow in late winter or early spring.

A stale seedbed can be treated with an appropriate herbicide to control emerging weeds. After 10-14 days, the field should be rotavated or power harrowed again and rolled before planting. Optimal seed-to-soil contact is achieved by maintaining a fine tilth (1.5-4 cm) in the seeding zone, with medium-to-large surface aggregates to minimise evaporation.

Protecting Against Vertebrate Herbivores

  • Birds are particularly fond of hemp seeds, so protective measures should be taken before emergence. Options include:

    • Scarecrows

    • Bird-of-prey kites

    • Laser scarecrows

    • Propane cannons

    • Bird netting (where appropriate)

    If none of these are readily available, a cost-effective option such as kites will usually suffice.

  • Although hemp is not a preferred food source, deer can still cause damage by grazing. Traditional deer fencing is costly, making it impractical in most cases. If deer are observed feeding on hemp, Garlic Barrier spray can be applied at a rate of 1-2 L/ha across the crop. The spray remains effective for 12-14 days, but it should not be applied if rain is expected within 48 hours, as reapplication may be necessary.

  • Rodents, such as rats and mice, may strip the bark from stems for nesting material, while rabbits can consume young plants and damage older ones. If this becomes a significant issue, Garlic Barrier can also be used as a deterrent.

When Considering Hemp Farming

The 3 year “Low-THC Industrial Hemp” Growers License fee costs approximately £600 (inc enhanced DBS check) but then there are other inputs including; land, seed, fertilizer N PK, security, agri-services (land prep, sowing, maintenance, harvesting), storage etc. 

These are all subjective costs which vary significantly!

Start Up Costs

There are domestic decortication processors on farms in the Central & North of England. These facilities have the potential capacity for processing much more, but market demand needs to increase. We also need to create new markets for hemp materials and get people buying domestic hemp products.

The Alliance is dedicated to helping this fledging industry thrive by partnering with other associations to see where we can be of mutual benefit.

Hemp Market

With Low-THC Cannabis (Hemp) still regulated as a controlled drug, generally, the regular financial system is not prepared to risk facilitating trade in “illicit goods”.

However, there are payment gateway providers who are more willing to bear the risk of facilitating transactions based on the reliance of the customer in upholding their legal responsibilities. There are a range of business services available for law abiding hemp and CBD businesses from a growing number of providers.

Payment Providers