At GTR Seeds, we believe in transparency, responsible breeding, and helping growers understand hemp compliance requirements. Whether you're cultivating CBD, CBG, CBGV, or CBDV hemp, understanding THC testing regulations is essential for a successful harvest.

Our compliance documentation includes hemp grower licenses, hemp handler licenses, Oregon Tilth Organic Certification, and Certificates of Analysis (COAs) for our varieties.

View Hemp COAs & Compliance Documents

Understanding Our Hemp Seed COAs

Our Certificates of Analysis reflect pre-harvest cannabinoid testing conducted on mother plants, generally around 30 days before harvest, consistent with applicable USDA hemp sampling requirements.

These results help document the cannabinoid concentrations of our breeding material at the time of sampling. However, they do not represent the final cannabinoid concentrations of mature, dried flowers.

Cannabinoid levels, including CBD, CBG, CBGV, CBDV, THC, and THCV, can change significantly throughout flowering. For this reason, pre-harvest compliance COAs cannot be interpreted as guaranteed finished-flower potency results.

Growers seeking examples of finished-flower cannabinoid profiles can explore testing information published by hemp flower retailers such as Cannaflower, Fern Valley Farms, Horn Creek Hemp, Rogue Origin, Sunset Lake CBD, and Tweedle Farms.

GTR Seeds does not guarantee finished-flower cannabinoid concentrations or regulatory compliance based solely on our breeding-stock COAs.

When Should Hemp Growers Test for THC Compliance?

Timing is one of the most important factors in hemp compliance testing, particularly when cultivating high-CBD varieties.

Under USDA hemp production rules, compliance is generally determined using total THC, which accounts for both delta-9 THC and its acidic precursor, THCA.

Total THC is commonly calculated as:

Total THC = Δ9-THC + (THCA × 0.877)

Our high-CBD varieties typically develop a relatively consistent CBD-to-THC ratio as the plants mature. Because both cannabinoids accumulate during flowering, waiting too long to sample can result in total THC concentrations exceeding the applicable hemp limit.

For many of our high-CBD seed varieties, we recommend beginning compliance monitoring around the fourth week of flowering, when developing flowers are approximately thumb-sized.

For crops planted in early summer in Oregon, this stage often occurs around mid-to-late August, although planting dates, genetics, environmental conditions, and seasonal variations can affect flowering schedules.

Important: Growers must follow the sampling windows and procedures required by their applicable state, tribal, or USDA hemp program. Our recommendations for monitoring cannabinoid development do not replace official compliance testing requirements.

Can Hemp Be Tested Later in Flower?

Growers who wish to extend flowering to maximize CBD production should consider frequent cannabinoid testing, potentially weekly, to monitor THC accumulation.

Testing throughout flowering provides useful information about cannabinoid development and helps growers make informed harvest decisions. However, individual results cannot guarantee that an entire crop will remain compliant.

CBD Seeds and THC Compliance: Understanding the CBD-to-THC Ratio

One of the most common misconceptions about high-CBD hemp is that finished flowers can consistently contain very high CBD concentrations while remaining below 0.3% total THC.

The relationship between CBD and THC production makes this challenging.

Cannabis plants containing functional CBDA synthase primarily produce CBDA, but the enzyme can also contribute to THCA production. As cannabinoids accumulate during flowering, high-CBD varieties often maintain a relatively stable CBD-to-THC ratio.

Many of our traditional CBD seed varieties exhibit ratios of approximately 25–28 parts CBD to 1 part THC, although actual ratios vary by genetics and individual plants.

For example:

These examples illustrate why high-CBD hemp can exceed 0.3% total THC as flowers mature, even when the plants were compliant earlier in flowering.

Growing conditions and harvest timing can affect overall cannabinoid concentrations, but they generally do not fundamentally change the genetically influenced CBD-to-THC ratio of a stable variety.

Why Pre-Harvest Testing Matters for High-CBD Hemp

Several of our established CBD varieties, including Lifter, Hawaiian Haze, Sour Lifter, Suver Haze, Special Sauce, and Sour Chem, are capable of producing finished flowers with CBD concentrations approaching or exceeding 20%.

At these concentrations, total THC may also exceed 0.3%.

This is not unique to GTR Seeds. It is a common characteristic of traditional high-CBD cannabis genetics.

Growers should understand the difference between passing an official pre-harvest hemp compliance test and producing finished flower containing less than 0.3% total THC. These are not necessarily the same outcome, and applicable laws may impose additional requirements on harvested material.

CBG, CBGV, and CBDV Seeds: Alternative Cannabinoid Profiles

Not all hemp varieties accumulate THC in the same way.

CBG Seeds and Compliance

Our CBG seeds are bred to produce high concentrations of cannabigerol while limiting downstream cannabinoid production.

All of our CBG varieties have demonstrated very low total THC concentrations, remaining below 0.3% even at maturity.

This makes CBG genetics an attractive option for growers seeking cannabinoid-rich hemp with reduced risk of exceeding THC compliance thresholds.

Our CBG breeding program includes traditional diploid genetics and advanced triploid hemp varieties developed for commercial flower production.

However, results can vary, and official testing is still required.

CBDV and CBGV Seeds

Our CBDV seeds and CBGV seeds represent years of breeding focused on developing novel cannabinoid profiles with commercially desirable characteristics.

These varieties have demonstrated low total THC concentrations, including at later stages of flowering.

Because cannabinoid ratios differ among varieties, growers should review available testing information and monitor their crops throughout production.

Growers seeking genetics with lower THC accumulation can also explore our low-THC hemp seed collection.

Can THCA or THC Seeds Be Grown as Compliant Hemp?

THCA-dominant cannabis and THC-dominant cannabis refer to the same category of plants. Most THC-producing cannabis accumulates the majority of its THC in the form of THCA before heating or decarboxylation.

Unlike our hemp-focused CBD, CBG, CBDV, and CBGV genetics, Type I THC varieties are not intended for cultivation under hemp programs requiring less than 0.3% total THC.

THC-dominant plants can exceed this threshold even during early growth, making them unsuitable for growers who must maintain hemp compliance.

Growers interested in cultivating our Type I seeds or triploid Type I seeds should ensure they are operating under the appropriate cannabis cultivation licenses and regulations.

What About THCA Flower?

THCA flower is not a separate botanical category from conventional THC cannabis flower.

Living cannabis plants primarily produce THCA rather than delta-9 THC. When THCA is heated, it converts into delta-9 THC through a process called decarboxylation.

Some THCA also converts or degrades during drying, curing, storage, and processing, depending on conditions.

Although some markets have historically distinguished THCA flower from conventional THC flower based on delta-9 THC concentrations, that distinction does not necessarily apply to hemp cultivation compliance.

For hemp production, total THC testing accounts for THCA, and THCA-dominant varieties generally exceed the applicable hemp threshold.

Growers and retailers should carefully review current federal and state regulations before cultivating, processing, or selling THCA-dominant flower.

For a more detailed explanation, read our article: Is THCA Considered Legal Hemp?

Hemp Compliance Frequently Asked Questions

Are GTR Seeds' hemp varieties compliant with USDA requirements?

Our hemp seed varieties are developed with compliant hemp production in mind. However, compliance depends on the genetics, growing conditions, sampling dates, testing results, and applicable regulations. No seed variety can be guaranteed to pass every compliance test.

Do your COAs show the final CBD or CBG potency of the flowers?

No. Our compliance COAs generally represent pre-harvest testing of breeding plants. Finished-flower cannabinoid concentrations may be significantly different. You can view our available COAs here.

Can high-CBD flower contain more than 0.3% total THC?

Yes. High-CBD varieties often accumulate THC alongside CBD, and mature flowers may exceed 0.3% total THC even when earlier samples were compliant.

Are CBG seeds less likely to exceed THC limits?

Our CBG-dominant varieties produce substantially less THC than traditional high-CBD varieties. Our CBG breeding program emphasizes low-THC cannabinoid profiles, with virtually no chance of passing 0.3% total THC.

Are THCA seeds considered hemp seeds?

THCA-dominant seeds are generally unsuitable for cultivation under hemp programs that require plants to remain below 0.3% total THC. Seeds themselves and the plants grown from them may be subject to different legal classifications.

Compliance Disclaimer: The information on this page is provided for educational purposes and reflects our breeding experience and understanding of hemp testing practices. Regulations vary by jurisdiction and may change. Growers are responsible for verifying current requirements with their licensing authority and obtaining all required testing and documentation.