There are many direct and indirect factors that can affect how plants grow.
These factors tend to be either biotic (living), or abiotic (non living).
In this guide, we outline each of those factors.
Summary – Factors That Affect How Plants Grow
It is often said there are 5 main factors that directly affect plant growth and a plant’s hormones (positively and negatively) – Light (sunlight), temperature, water, humidity and nutrients.
But, this is a simplistic view, and in reality there are more direct and indirect factors to consider.
Factors can be divided into biotic and abiotic factors.
Living things like plants, animals and fungi. They include:
- The plants themselves
- Animals that affect the plants, soil, water etc.
- Secondary plant life that affects the soil and the primary plant (like other types of plants, trees, pest plant species etc.)
- Soil microbes (bacteria, fungi etc.)
All the non-living factors that affect living organisms (like plants) and ecosystems (like soil ecosystems). They include:
- Climate – average rainfall, temperature, and wind patterns.
- Soil type, soil fertility and other soil variables (like soil health, and soil quality)
- Geographic location – US plant zones, different soil conditions in each location, landscape
- Other Environmental Factors – Light, temperature, water, humidity, and nutrition, Seasons – summer, autumn, winter, spring
- Human Activities, Inputs & Factors – adding water, adding fertilizer, adding pesticides and herbicides, adding other soil mixes, soil and plant maintenance etc.
– Biotic Factors That Affect How Plants Grow
The Plants Themselves
All plants are different in the conditions they grow best in and what they need to grow over a certain period of time.
Different plants might:
- Need different climates and environmental conditions to others – for example, some plants might be better in colder climates and the shade, whilst others might need warmer climates and need more direct sunlight
- Need different types of soil – for example, root vegetables need softer/looser soil that allows them to establish a root structure
- Need different pH soil – some plants grow better in slightly acidic soil, some in neutral soil, and some in alkaline soil
- Need different amounts of water – for example, cotton is a water hungry crop that needs much more water than plants that can grow in the desert (such as the Gao tree that grows in Niger)
- Need different growing season lengths, and grow in different seasons – for example, wheat has a 90 day growing season. Some plants may also grow better in Fall/Autumn compared to Spring
- Live longer than others – some plants are perennials (live longer than 2 years) and others might be annuals or biennials
- + other plant specific factors and considerations
Learn as much as you can about what it is you are growing and what they need to grow before you grow it.
Animals can help or hinder how the plant grows.
Wild animals or destructive animals might walk on and damage the soil, or walk on or eat the plant directly.
Some wild animals on the other hand like bees are beneficial to pollinating flowers and helping with growth, and worms can help with breaking up organic matter in the soil.
Secondary Plant Life
Same thing with secondary plant life – they can help or hinder how plants grow.
Weeds and pest plant species may restrict the plant you are trying to grow. A plant like hemp can constrict the growth of other plants out in the wild.
But, trees and other plants can actually add nutrients to the soil and make it more fertile. Adding secondary plant life can also contribute to better biodiversity. Companion plants are plants that grow well with each other. Incompatible plants don’t grow well together.
Beneficial soil microbes (beneficial bacteria and fungi) help with soil health, and also breaking down organic matter into soil nutrients.
Microbes can die off if the soil health declines, or if chemicals like pesticides are used that kill off the beneficial soil microbes.
Beneficial soil microbes tend to thrive in healthy soil with plenty of organic matter.
– Abiotic Factors That Affect How Plants Grow
Climate usually involves average rainfall, temperature, and wind patterns.
Rainfall helps with water supply to the plant, temperature affects many factors (the expansion and constriction of soil being one of them, and obviously on the plant itself), and wind patterns are important for things like wind soil erosion.
Different plants grow better in different climates – the USDA produces a plant hardiness zone map that takes into account average lowest temperature in a location (they have zones 1 through to 12). Australia does something similar (zones 1 through 7).
You can view each here:
You can also view plants that might grow in these regions at:
Soil factors usually involve:
- Soil Type
- Soil Fertility (nutrient supply in the soil, pH of the soil, parent material under the soil, clay content in the soil, bulk density of the soil, moisture and water content in the soil, and other direct and external factors)
- Soil Health
- Soil Quality
Land, air and water conditions and factors vary within states, from state to state, from country to country, and worldwide.
Climate, topography (how sloped or flat the land is), altitude, and soil (parent material and natural rockscapes) are some of the factors that vary between geographic locations.
For example, growing in arid parts of Australia is going to be different to the more tropical parts, and growing in each state in the US means different climates and different state representative soils you are dealing with.
If we take a location like Niger – Gao trees can grow well there in some parts because they suit local conditions. So, local conditions and factors play a big part.
Other Environmental Factors
- Wind and water erosion (and other land degradation issues)
- Natural organic matter
- Seasons – summer, autumn, winter, spring
- + other environmental factors
Human Activities, Inputs & Factors
Factors such as:
- How often humans till or turn the soil
- How often humans spray with pesticides or herbicides
- How often humans fertilize with synthetic or organic fertilizer
- How often human irrigate the plants and soil
- Whether humans add soil to the natural soil mix
- Whether humans adjust or modify the growing conditions such as growing in a raised flower bed or greenhouse compared to in an open space or open field on the natural ground
- + Other practices that improve or destroy plant life and the conditions they live in
With agricultural and commercial plant growth, there’s many human activities like irrigation, crop rotation, tilling, harvesting and more that can impact plant growth.