by Dr. Chris Kline 

All New Square Foot Gardening Has Much to Offer Gardeners

Square Foot Gardening (SFG) is not new. It was introduced by Mel Bartholomew, the author of this book, over twenty five years ago. In a nutshell, it is a raised bed gardening technique in which 4x4 boxes are divided into square foot sections for planting, but it is much more than that. Mel’s book is chock full of ideas that gardeners need to be aware of, or reminded of, regardless of whether they are planning a true “square food garden” or not. Listed below are the main topics of the book and suggestions of how they may apply to greenhouse gardening.

Space Saving

In a Square Food Garden, plants are added to each square foot according to the minimum space that is needed between plants, which is found on any seed packet, rather than having unnecessary space between rows as is the case with larger single-row gardens. The need for space between rows is eliminated because a 4x4 foot planting area can be tended from the sides without walking on the soil. This means no compacting of the soil which eliminates the need for tilling. A three foot isle is recommended between and around boxes. With proper planning and planting a Square Foot Garden can be more productive in just twenty percent of the space of a traditional garden.

Location

The small size in comparison to a traditional single-row garden allows one to have several smaller garden plots and move them closer to the house. In a greenhouse, one could build two foot wide boxes to be positioned by the sides. These could sit on the ground or be raised to a convenient height. Don’t have a greenhouse? With 4x4 foot garden boxes, cutting and bending inexpensive ½ inch PVC pipe to form two corner-to-corner arches easily makes a frame which can be covered with clear plastic to make a small season extending cold frame. Because the boxes are filled with a light soil mix and are small, they can even be made portable by adding a plywood bottom, but care should be taken to insure proper drainage.

Use the Best Soil

Container gardening has always had the advantage of allowing one to start with the perfect growing mix and by locating a garden on top of existing soil much of the work of trying to cultivate perfect soil can be eliminated including soil pH testing, double-digging and never-ending soil improvements. The book proposes using "Mel's Mix" which may be a little gratuitous considering that many gardeners have been using similar mixes for years, but none-the-less provides a growing mix that is a formula for success. The mix consists of equal parts of peat moss, vermiculite and compost, all of which are readily available online and in hardware and garden centers. Be sure to use horticultural grade vermiculite; and, if you plan using store bought compost, mix several brands together. This helps to insure a well balanced nutrient source for the mixture.

6 Inch Depth

The author proposes that soil only needs to be prepared for a SFG box to a depth of 6 inches! The lesson here is that where some “deep root” plants may prefer more, the majority of plants develop just fine when grown at this depth. This being the case, why not consider starting any garden with six inches of great soil on top regardless of what efforts are taken to improve the inferior natural soil base. For container gardening, consider if the space below six inches is really necessary for the plants being grown. If not, fill this space with something like an upside down pot, or use shallower growing containers.

No Fertilizer

The author proposes that the all new SFG does not need any fertilizer-ever! By starting with a soil mix that contains 1/3 quality compost, the need for fertilizer is eliminated or greatly reduced. One will, however, need to add additional compost from time to time. With all the great soil and foliar fertilizer products available, where they may not be necessary, it might be a stretch to deny their benefits.

Keep it Neat with Grids

One of the neat features of the SFG are prominent and permanent grids that are added to the top of the box to help with visualizing and planting to best use garden space for a maximum harvest. Whether one is using boxes or not, it is best to have some way of defining garden space. There needs to be space to walk and space to grow clearly defined. Organizing a garden into marked squares makes properly spacing plants easier and the end result tends to look better.

Knowing When to Plant

This book also provides limited information on some of the most common garden plants, but more importantly it has some great information on developing a planting schedule. Numerous charts are provided that help one to determine the best time to plant various crops based on the date relative to the projected last spring or fall frost for the area. One resource provided is located online at www.victoryseeds.com/hardzone. This site has frost dates and hardiness zone maps for the entire United States. There are also links to local university extension services which can be very helpful with determining planting calendars.

Based on one of the best selling gardening books of all time, All New Square Foot Gardening is a must for the serious gardening enthusiast.

Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net. You can contact him at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it