Marijuana PlantsWhy do marijuana plants from the same motherplant or seed strain grow so differently?
© Copyright, Nigel Salazar, 2015

Why Marijuana Plants from the Same Strain Grow, Yield & Look Different

Sometimes on marijuana grower forums I see people claiming it doesn’t matter what you feed your marijuana plants.

They falsely claim that genetics determine all your outcomes.

However, I’ve seen plenty of evidence that nutrients and other factors affect how marijuana plants grow.

Individual marijuana plants aren’t identical copies of their original genetics.

They’re heavily influenced by what you feed them and what environment you provide them.

For example, I grew out a sea of green crop of clones that I personally cut from a Golden Goat motherplant… and noticed significant differences in how they grew.

The clones were all in the same deep water culture system indoor grow op with identical feeding and lighting.

Yet, some grew faster. Others grew taller or shorter. Some had more grams of bud per plant than other plants.

These differences show variations in the two major foundations of plant growth: their genetics, and their environment.

Marijuana plants have built-in genetics that control many factors of their development.

But those genetics drift, creating variation.

When you grow marijuana from seed, you often see genetic drift, as some of your plants look different from each other, and different from what the seed breeder’s website photos show.

When growing marijuana from cuttings, the genetic drift is less drastic, but you still see it.

Along with genetic drift, you see variations that come from the interaction of genetics and your marijuana plants’ environment and inputs.

Here’s one situation like that…

Marijuana plants grown from one motherplant might be taller or shorter than each other, or produce more bud or less bud, depending on whether they’re directly under your grow lights, or off to the side.

The marijuana growing team here at has done side-by-side tests with cuttings taken from a stable motherplant.

Some were fed General Hydroponics. Others were fed Advanced Nutrients.

Everything else was the same for all the cannabis cuttings.

The ones fed Advanced Nutrients grew faster and produced more and better buds.

Some people call these variations “phenotypic plasticity.”

By this they mean: variations in how marijuana plants look and perform based on the interaction between genetics, environment, and inputs.

Growing marijuana from motherplants gives you the least phenotypic plasticity, but you still see slight variations depending on genetic drift inside each clone.

Growing marijuana from seeds, especially the hybrid Sativa + Indica crosses that dominate today’s marijuana strains, gives you a much wider range of genetic drift.

Marijuana grow rooms with uneven lighting, inferior water or hydroponics nutrients, poor climate control, non-standardized trimming and topping, and other factors can result in phenotypic plasticity that shows as stark variations between individual plants.

Variations such as where the plant is located in a grow room, or how it’s fed or topped, can cause plants to look and grow differently.

For example when selecting motherplants, you might choose the “best marijuana plant” from a particular grow season, but that plant was only “the best” because it had better nutrition or environmental factors compared to other plants.

Variations caused by genetic drift are more reliable.

If you grow from seed, you might get two or more distinct types of marijuana plants from the same strain.

This could be a sign of poor breeding. Or it could just be natural genetic variation.

You get to choose which one is your favorite for seed breeding or as a motherplant.

Many marijuana growers, especially people doing large-scale production, dislike genetic drift and phenotypic plasticity because it creates logistical problems.

For example, you want all your plants to grow to the same height at the same rate so your lights can be at uniform height.

But genetic drift and/or phenotypic plasticity could result in an uneven canopy with some plants 4 feet tall in bloom phase while others of the same strain are a foot taller.

Or some marijuana plants from the same cuttings or seeds might be ready for harvest at 56 days into bloom while their sisters need 63 days to be ripe and ready.

The main thing to remember is marijuana plants aren’t machines that will grow absolutely 100% identical to each other in all circumstances.

Another thing to remember: optimize your feed program, light patterns, trimming and topping, and other environmental factors so each of your marijuana plants get identical environmental and input factors.

When I look at my marijuana plants and see differences even in the same seed strain, I remember that old saying: variety is the spice of life!

The main thing is that conditions you grow your marijuana plants in, and what you feed them, make a big difference in how they grow. It’s not just in their genes!

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