How Do Plants Grow Part 1: Roots

What is a Root System?

A root system seems pretty straight-forward. Roots absorb water from the dirt, which goes to the plant, and then that’s how plants grow, right? Not quite.

The whole root system requires more than just plant roots. To actually absorb nutrients, plants mobilize entire networks of organisms called microbes, who support the roots’ nutrient uptake (much like the microbes in our own digestive systems). 

In exchange for help from these invisible beasties, the roots secrete goodies which give the microbes energy, and protect them from microscopic predators. This is partly why soil clumps so tightly around roots. The roots and soil microbes are creating a microscopic system to ensure their survival!

How Do Plants Grow: Community vs. Competition

It may sound simple enough, plants give “X in exchange for Y”. But what scientists and gardeners alike are curious how roots, microbes, and people, can understand which microbes are friend and which are foe.

Previously, it was thought that all microbes cause disease, so perfect growing conditions have zero microbes.This sparked the development of pesticides and fungicides. “If we destroy all the microbes, plants will grow uninhibited, right?” Wrong. 

Beneficial microbes also exist, and they help plants thrive. With modern research methods, we’re able to see that not all microbes cause disease, but we still don’t understand how plants know who to negotiate with. 

How Plants Grow | Barefoot Garden Design

How Do Plants Grow: Working Together

One idea is that each plant’s roots secrete unique goodies to attract specific microbes. For example, plants in the Legume Family form a relationship with special bacteria called Rhizobia, who make nitrogen available for plants. The treats exuded by the Legume roots entice the Rhizobia to form nodules in their root system, allowing the plant to receive plenty of nutrients.

Other plants, such as ‘Ghost Flowers’, use microbes very differently. These plants produce no energy of their own. Instead, their roots form a relationship with special fungi, who penetrate tree roots and siphon energy off to feed the ghost plants–  in exchange for a share of the loot, of course! 

How Do Plants Grow: Adding Science to the Garden

Roots are the foundation of plant growth, and understanding how the whole root system works makes us better gardeners. When we are informed about what’s going on beneath the surface, we can create gardens where our plants truly thrive. 

So next time you’re preparing garden beds, be sure to keep the science in mind. Is your soil fluffy enough that roots can travel through it? Is there living soil (not just potting mixes and fertilizer) that can provide the microbial community your roots need? Remember, to really thrive plants need a whole community, just like us! 

What gardening tips and tricks do you have for healthy roots? We’d love to hear about it! Leave us a comment on social and let us know how you use science in your garden!