With so many high-THC cannabis seed varieties now available, many connoisseur cannabis growers prefer strains with a proven genetic pedigree for high terpene levels. Terpenes are organic, naturally produced compounds which impart a variety of aromas and flavours in your buds.

High terpene strains are typically bred from parent genetics known for exceptionally dank buds. As well as high THC levels you can expect buds that stink with an old-school pungency that fills the room once the jars are opened. For many cannabis lovers, a great terpene profile is the difference between good buds and truly memorable ones.

What is considered a high amount of terpenes in weed?

The most professional cannabis seed banks and breeders rely heavily on high-tech analytical laboratories to provide independent, unbiased lab reports. These allow useful checks on existing strains.

Lab analysis also allows precise, high-quality breeding for future strains. It allows less interesting genetic lines to be quickly dispensed with, focussing genetic attention only on those individuals with the highest total terpene content and heaviest cannabinoid loading.

Terpenes are measured by their weight in cured, dry buds. If you took 100g of a strain with a 1% terpene content, there would be 1g of terpenes and 99g of terpene-free buds.

Cannabis growers should be aware that it’s not just the quality of the cannabis seeds which determines the final terpene levels in their buds. The quality of plant care during the seedling stage, vegetative growth and the cannabis bloom phase will all play a huge role in the final terpene content and THC level.

Use of LED grow lights can allow plants to reach higher THC/terpene levels than HPS. Use of slow release organic nutrients, such as those from BioTabs, allows a ‘water-only’ grow approach. This greatly simplifies growing, especially for those that struggle with over/under feeding using mineral nutrients.

Differences between various laboratories & new analytical technology

Dutch Passion have used various independent analytical laboratories over many years, some Western European and some Eastern European. Throughout that time the use of independent labs for an unbiased view of the terpene/cannabinoid measurement has been extremely important.

Important, easily hybridisable genetic lines are quickly identified. Conversely, less fruitful genetic lines can be immediately discarded, allowing highly targeted breeding and selection.

It’s worth noting that whilst labs are in general broad agreement, if you send the same bud samples (from the same plant) to two different labs you may get slightly different quantifications returned in the analysis.

Some labs have more sophisticated equipment than others, allowing them to detect terpenes that other labs simply can’t. Farnesene, for example, is one elusive terpene that many labs can’t detect or quantify.

Buds from a recent autoflower seed introduction, Auto Melonade Runtz, were analysed by one of the more sophisticated labs and found farnesene was actually one of the dominant terpenes (in the top-6) present. Had the sample been analysed by a different lab farnesene may not have been identified or quantified.

Get your bud samples analysed by the most sophisticated labs, and they may be able to detect more terpenes than a less advanced lab. Getting buds analysed by the most advanced labs is more expensive than a basic lab test, but the extra data and genetic information tends to be well worth the cost.

How are terpenes measured in cannabis?

Gas Chromatography (‘GC’) is one of the more common analytical techniques. It allows the different individual terpenes to be separated, identified and quantified. Usually, the total terpene content is expressed as a %w/w in the original bud. So 1% terpenes mean that 1% of the weight of the buds is made from terpenes.

Although dozens of different terpenes exist, often 80-90% of the total terpenes in a given strain comes from just 5 or 6 individual terpenes. Some of the more common terpenes include myrcene, pinene, caryophyllene, limonene and linalool.

What are the main factors influencing the terp production?

•   Cannabis seed genetics are a primary factor in terpene production. Even the most experienced professional grower can’t grow terpy buds from poor genetics. Choose good quality cannabis seeds from a trusted source, preferably with independent lab reports to back up their claims.

•    Nutrient control is another key parameter, aim to keep your plants in the nutrient sweet spot from seedling to harvest.

•    Lighting is key. Preferably LED lighting with supplemental UVA/UVB during later bloom, aim to keep your plants in the optical sweet spot from seedling to harvest.

•    General grow conditions. Aim to keep conditions stable, avoiding temperature/humidity extremes. Target temperatures around 25ºC (77F) during lights-on, and a few degrees cooler with lights off. Ensure ample air flow/circulation.

•    Aerated grow containers, such as large felt sacks, airpots or similar allow extra levels of root oxygenation and better growth.

Note that the top two most common quality-limiting errors seen by growers are over-watering and over-feeding.

What are the highest total terpene content levels in weed to date?

The highest terpene levels seen so far are 2.6%, from Dutch Passion Blue Zushi (feminised seeds only). Note that the use of autoflower seeds and/or feminised cannabis seeds will both give high terpene harvests.

Select your strains carefully, remember that high-THC terpy strains are rarely found by accident, mostly they are the result of several years of professional selective breeding.

Other strains such as Auto Cinderella Jack (1.6% terpenes), Auto Mimosa Punch (1.54% terpenes) have all been bred to deliver terpy buds with 20%++ THC levels.

It’s worth adding that Dutch Passion, and some other leading breeders, won’t commercialise a high THC strain unless it also boasts a rich terpene profile.

How to boost the terpene production when growing from seeds

To push your cannabis seeds to their genetic limit it’s important to start out with the best genetics and grow them under optimised conditions throughout their life cycle. Growers that have invested in a well-organised grow room with quality LED lighting and professional climate control are best positioned to grow terpene-dripping buds.

For the consumer, the difference between buds with a high terpene content and ‘average’ buds couldn’t be clearer. Terpy buds have massively more appeal than bland buds, not only the jar appeal is improved. But a full terpene loading means that your smoking/vaping experience is accompanied by delicious taste and flavour which many believe helps modulate (or ‘steer’) the high.

For a deeper dive into the art of growing terpene rich buds, check out the following article.