Knowing what the best size and why will help you maximize your indoor gardening thus

gives you an advantage of optimally using your grow box in the long run.  Here are some

examples of grow boxes of different widths with their advantages and disadvantages.
•    Widths smaller than 18 inches – can put some plants too close together when you

occupy two rows.  There is also a possibility that roots will be crowded for some larger

crop varieties.  When it comes to water, there is less availability which can lead to

water stress and causes water to dry fast during hot weather.
•    Widths wider than 18 inches – watering and feeding of plants can be very

difficult due to its large space.  Growing plants in a very large area could be less

efficient in terms of fertilizing and watering the plants because not all the plants will

get the available nutrients, like young plants, their roots are not that long enough to

reach for the water and nutrients which in turn makes them suffer from lack of moisture.
•    Width four inches wide – has been worked out for maximum yield and efficiency.  

It allows planting of four rows for most plants and two rows for plants grown vertically.
•    Width three inches wide – most people think that they can get by with a three

inch wide box instead of getting the four inches.  At the end they pay much more because

of the lost yield.  The reason behind is that plants usually needs the two feet of space

between the inside rows for light and air.
•    Width five inches wide – this size of box is no longer recommended due to the

difficulty in reaching the center of the box and it requires planting across instead of

lengthwise for efficient planting.  Watering as well is a problem because it is done by

hand since automated watering does not work with planting across.
•    Width eight inches wide – works effectively most especially if plants can extend

their roots down into the native soil.
•    Two and three inches deep – aesthetics is the benefit of having a deeper box.  It

is also of great advantage for people who have difficulty bending over to work neat the

ground.  This depth has made growing successful for some people.
These are just some of the sizes of grow boxes available but with these examples you now

have the knowledge of how the size affects growing of plants.  Just keep in mind that

eight inch depth is the most efficient when it comes to watering and feeding which in

turn makes you manage yourself accordingly.  Size really does matter but in the end it

still depends on your preference of the size of grow box that best fits your needs.