So getting to know a little about the root system will provide you with the knowledge to grow the healthiest plants. The picture onthe left details the root tip. Knowing the parts will help understand why the plant is behaving in a certain way. Yes, we said behaving. There is plant behavior just like there is animal behavior. Plants are just a lot slower moving.

Here are the main parts of a plant root:
     A - Fluid Vessel
     B - Lateral Root
     C - Root Hairs
     D - Growth Zone
     E - Root Cap

Roots serve many functions.
They are a foundation to support the growing plant. They grow out and hunt for foods and water, absorb oxygen, and release carbon dioxide. They sometimes store excess materials for later use. The health of a plant's roots are commonly neglected, so that's why it is very important to understand what we usually cannot see.

Root systems vary greatly in size!
They can be tiny, like those of a seedling, perhaps a few inches long, to those of a 200' redwood which can grow larger in size than the visible tree itself! Contrary to many beliefs, roots tend to grow outwards instead of downwards, thus effectively covering a larger surface area underground. This horizontal growth is so the roots can collect rainwater.

The absorption of water and nutrients takes place behind the plant's root tip through tiny hairs.
These hairs are usually evident only when looking at young roots growing in a loose and airy medium like vermiculite or cocopeat. In fact, when developed in wet soil or in water, roots rarely develop such hairs, which leads one to distinguish between an "air root" and a "water root." These root hairs are extremely delicate and usually drop off as the root tip grows longer into a growing medium that is less than ideal.

The method in which roots absorb water and nutrients is called diffusion.
In this process, water and oxygen pass into the root structure through membranes in the cell walls. Oxygen is absorbed and then utilized for growth. And in return, the roots give off carbon dioxide. The absence of oxygen in the root zone causes asphyxiation, damaging the roots and adversely affecting the tops of the plant as well. Stagnation of water in the root zone can also cause asphyxiation, in addition to root rot. Just imagine how you would feel standing around in a pair of wet boots 24 hours a day, seven days a week!

This leads us to the topics of proper irrigation and aeration.
What is "proper" irrigation for your favorite plant??? Just put yourself in the plant's shoes. On a hot day in direct sunlight, you can bet you'd be thirsty. So make sure to irrigate your plants more often during hot spells and in strong light, whether outside or indoors. When the light is softer and temperatures fall, your plants will naturally transpire less water. So go easy with the can under these conditions!

Remember, you do not want your plants roots to soak in stagnant water.
And you surely don't want them to dry up. So check your growing medium frequently during extreme temperature swings. One advantage of some of the new soilfree mediums like cocopeat and rockwool is that they have a higher water holding capacity than many fine potting soils, and at the same time they maintain their air holding capacity to protect against asphyxiation. Plants grown entirely in water, as in the case of hydroponics, are always guaranteed the right amount of water and nutrients since their roots are always bathed in a circulating flow of nutrient enriched water.

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