Guide to Testing Hemp Crops

2020 Farmer's Guide to Testing Hemp Crops

Industrial hemp farmers need to be aware of the new USDA laws in 2020. In this farmer's guide to testing hemp crops, learn the new regulations, requirements, and resources to ensure you stay compliant.

When to Test Hemp Crops 

For our latitude in the south, daylight hours peak around 14.5 hours during solstice (June 21).  Beginning in late July to the end of August, those hours decrease to about 12.5 hours. 

Photoperiod sensitive Hemp will be triggered into its flowering stage during the months of July and August. Hemp growers can observe this phenomenon by the presence of white hairs, or stigmas protruding from the pistils of the plant, located along with the inner node.  

With the shortening of length between nodes, referred to as “stacking”, the hemp flower begins to mature. Around this same time, plants ought to be identified as male or female. White-haired stigmas, for the females, and pollen sacs for the males.  

When and How to Test Your Crop According to New Regulations?

As this triggering stage progresses, Cannabinoid content begins to activate due to predetermined genetic disposition and environmental stresses. This response in Cannabinoid synthase is caused by reactions in the plant’s own immune defense system, for protection against stress. 

Depending on your cultivated variety of hemp, it is pertinent to know when the timing of THC-synthase transitions from THC-A to Delta-9 THC. 

The new USDA hemp regulations of 2020, suggest hemp testing 15 days prior to harvest by a DEA approved hemp testing lab.  

This means YOU SHOULD TEST YOUR HEMP CROP INDEPENDENTLY of State Inspections in order to know where your THC levels are. This should be done two weeks before the inspection or four weeks before harvest.

What is “HOT” Hemp?

Hemp is defined as any Cannabis sativa L. cultivar that has a delta-9 or Total THC content of less than 0.3% on a dry mass basis. 

Prevent your crop from becoming unusable and know the difference.

2020 USDA Lab Testing Requirements 

This year will be especially difficult for the industry and hemp farmers looking to harvest an interstate commerce compliant crop that meets New Federal Guidelines and the Interim Final Rule (IFR) for Total THC thresholds.  

These guidelines are presumed to go into effect after October 31st., 2020.  Some states have chosen to preemptively impose these new guidelines, or have had their state’s USDA Hemp Program Plan Approved with the new CBD guidelines.

USDA Hemp Testing 

USDA Hemp testing includes a 15-day window before harvest, with testing completed by a DEA certified lab.  

This new constraint with the USDA hemp regulations of 2020 makes the farmer’s job and hemp business regulations more burdensome to achieve.

Farmer’s are encouraged to pay for and send their own samples to a DEA Certified Lab to monitor their crop’s THC content prior to notifying the Department of Agriculture of a sampling inspection for harvest.  

This means that farmers will likely need to plan for earlier harvest times and be testing THC content of the developing buds between the second and fourth week of flower.  

Harvesting early immature flowers create a less cannabinoid-rich flower, which brings less of a higher value in the market. Most varieties need 8-10 weeks to set mature flowers.

Harvesting earlier will need to take place between the 4th and 8th week of flower depending on the variety.  

The Department of Agriculture needs a two week lead time to schedule sampling, and then 3 days to 2 weeks to get the results back from the State lab. 

So you should be testing a month before harvest ensuring compliance and planning for inspection and harvest.

Where are the Hemp Testing Labs in Tennessee?

Tennessee has a few DEA hemp testing registered labs, whose handling and testing procedures meet the USDA hemp testing protocols

Canvast Supply Company has had a great experience with New Bloom Labs in Chattanooga as our preferred lab partner for quick turnaround time and transparency for the multiple products we offer.  

New Bloom Labs


New Bloom has a great FAQ page for all your testing needs.

Utilizing a single lab with hemp testing equipment such as gas chromatography and/or high-performance liquid chromatography will provide you with more consistent variance in your lab results overall.  

Cannabis testing labs that follow the DEA hemp testing protocols are going to be your best bet in getting accurate results. 

All of our products go through New Bloom Labs as our third-party certifier. They are one of the first Tennessee Labs to undergo the DEA hemp handling certification, with FDA hemp compliance, ISO-9000, and ISO-7163.   

Tips for Sampling your Crop during the Growing Season

  • Know the date to maturity for your variety of hemp planted
  • I rule of thumb is to test your flowers for potency when they are about “thumbnail” size
  • Take samples from the flowers closest to the top, they will tend to be the most mature.
  • Review the USDA sampling guidelines
  • Review the USDA hemp testing protocols
  • Notify your state inspector for a scheduled inspection three to four weeks before your final inspection.
  • Once your regulatory agency has cleared you for harvest, plan on taking final samples that are representative of each batch harvested.  
  • The last tests should be taken after the hemp material is dried and in a disposition ready for sale.
  • A 6 (six) panel test will include; microbial, mycotoxins, terpenes, pesticides, heavy metals, and THC potency.

We highly encourage all growers and manufacturers to utilize the best available resources and practices in producing their hemp crops. 

Testing for THC compliance is of the utmost importance in legally protecting the hemp supply chain from farmer to end-user.

For more information on growing hemp and budgeting for your hemp season, check out our Holistic Farm Planning Workbook.

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