CBD Seeds Side by Side: Balanced Versus Dominant
Put two packs of CBD seeds beside each other, one marked 1:1 and the other 20:1, and the two look the same: the same brand foil, the same seed count, contents which nobody’s eye can separate apart. Grow them in the same tent and they part ways from the first step and do not converge again. The cause is a single gene, and the easiest way to see what it does is to track the two packs through each stage both share: the breeding that made them, the seed, the seedling, the flower tent, the harvest, the jar, the lab report and the border. The ratios quoted as examples below are drawn from the range at https://calmcbdseeds.com, and that range runs 1:1, 2:1 and 20:1 and a highest line at about 30 to one; the biology holds the same whichever shop the seeds come from.
Before the Seed Exists
Cannabis settles if it is going to produce THC or CBD at one position on the genome. The gene there comes in two forms: one codes the enzyme that converts the common precursor into THCA, the other the enzyme that converts it into CBDA. Each plant holds two copies, one inherited from each parent, and the combination sets the chemotype. Two THC copies give a THC-dominant plant. Two CBD copies make a CBD-dominant one. One of each gives a balanced plant, because the two versions are codominant and not one of them silences the other.
The balanced pack was made by pairing two balanced plants, each carrying one copy of each version. The CBD-dominant pack was bred by pairing two plants which each carry two CBD copies and not a single THC copy between them. This one fact at the bench decides everything downstream, and it is already inside the seed before it is packed.
The Mendelian Split
Cross two balanced plants and the seeds fall themselves by the simplest arithmetic in genetics: a quarter get two THC copies, a quarter inherit two CBD copies, half get one of each. In a pack of 10 seeds that works out to, on average, around two THC-dominant seeds, around two CBD-dominant seeds, and about five genuine balanced seeds. The pack is sold by its parents, and in the case of half its seeds the label fits; in the case of the other half it is a description of something else. Calm CBD Seeds states the expected split on each balanced line, which means the buyer sees ahead of sowing that a portion of the plants are going to differ from the stated ratio.
The CBD-dominant pack has no such spread. Every seed got a CBD copy from each parent, every plant will be CBD-dominant, and the ratio on the foil holds to all of them, give or take the small differences in the amount of total cannabinoid an individual plant builds. The trade describe such lines “breed true” for chemotype; the term refers to precisely this absence of surprise.
Weeks One to Four
At this stage the two packs appear the same again, and the resemblance holds further than most growers assume. Chemotype leaves no mark on a seedling. Leaf, colour, stem spacing and growth rate are governed by different genes entirely, and the three chemotypes of plant in the balanced pack come up without any visible difference beside one another and from every plant in the CBD-dominant pack.
The one real distinction at this stage comes from ancestry not chemotype. Strains with strong hemp ancestry, which includes a number of less developed CBD-dominant lines, are inclined to grow taller and branch less. A well-worked 20:1 line grows like any indoor hybrid; a young one may still shows the field in its shape. Not one of these tendency tells a thing about the ratio in the flower.
When the Resin Comes In
In flower the two packs start to give hints, and most of the clues mislead. Trichome coverage is the usual one a grower judges, and it used to be a reasonable guide: first-generation CBD-dominant strains showed visibly less frost than their THC cousins, an unwanted legacy from hemp. Modern lines have mostly closed that gap, and a less frosted plant from the CBD-dominant pack may perfectly well test precisely where the foil said. Resin density and chemotype are inherited separately.
Smell is an even poorer guide. The terpene chemistry lives on yet different genes, so the THC-dominant plant hiding in the balanced pack can smell identical to the balanced one beside it, and both can smell identical to a plant from the CBD-dominant pack. People who try to separate a balanced pack by nose in week eight are right about half the time, and that is not any better than leaving the plants unsorted at all.
How Late Is Too Late
At this stage the two packs diverge in a way that favours the grower of the CBD-dominant pack and also the CBD-dominant plants sitting in the balanced pack. CBDA degrades rather slowly than THCA, so a CBD-dominant plant allowed a week beyond its peak retains most of its cannabinoid load, where a THC-dominant one in the same neglect has already started converting THC to CBN. The cloudy guidance nonetheless applies; it holds on account of the terpenes, which degrade on every plant whatever the chemotype, and a late, rushed CBD flower tastes of very little however good the lab result is.
Why Each Plant Gets Its Own Label
The CBD-dominant pack goes into one jar. Every plant from it holds about the same ratio, and blending them alters nothing anyone would measuring. The balanced pack should never be treated the same way. Pool its 10 plants in a single jar and the contents become a ratio that no foil could have predicted, weighted by whichever plants yielded most, and no later test can pull apart what went in.
The habit that saves the trouble is dull: harvest the balanced pack plant by plant, dry each apart, number them, and test each one one at a time rather than after anything is mixed. This is the one point in the whole grow at which the three kinds of plant in the balanced pack can yet be kept apart short of a lab, and then only because each is at that moment in its own bag.
Reading the Two Results
Send a sample from each jar to a laboratory and the two packs at last are legible. For the CBD-dominant pack the reports come back grouped closely around the advertised ratio, differing mainly in total cannabinoid content rather than in balance. For the balanced pack they arrive back in three groups: a few plants showing nearly all THC, a few with almost all CBD, and the rest sitting around one to one. Nothing of this result is a defect; it is the bench cross expressed as numbers.
Over-the-counter test kits are sold for growers without a lab, and most show whether THC is there rather than how much. That is sufficient to separate the THC-dominant jars out from a balanced pack and not to assign a ratio to the rest, and that suits the commonest need: knowing what of the 10 jars is going to surprise a guest.
Where the Law Reads the Numbers
The last place at which the two packs diverge is legal, and it trips growers who assumed “CBD” meant “hemp”. The majority of jurisdictions define hemp by a THC limit, a fraction of a percent of dry weight, with the precise number varying by country and over time. A plant from the CBD-dominant pack making twenty percent CBD at twenty to one at the same time makes around one percent THC, and that is many times over the majority of thresholds. Certified hemp cultivars are bred to keep total cannabinoid output down so the THC fraction stays under the line at maturity; CBD seed lines are selected for high content and allow the THC scale with it. A seller that gives only a ratio is selling a flower line; anyone who needs a legal hemp crop should ask for a tested THC percentage at harvest and order no line that does not show one.
Beyond the threshold issue, the word on the foil changes very little about the law on the seed as such. In places where holding cannabis seeds is permitted and germinating them is not, the balanced pack and the CBD-dominant pack fall under the same rule as any other pack. Where the plant is permitted outright, the decision between them is the grower’s and nobody else’s. No part of this article is legal advice, and the law which applies is the one in the place the seed is going to be grown, rather than the one where it was sold.