Square Foot Gardening 101: Part Two

 I have been meaning to get this post up for a while now but life happens! So let’s just get right to it!

In SFG: Part 2 – I am going to explain how to build your square foot garden boxes, the soil to put in them and the grid system. I will also touch on some of the reasons behind it all. If you missed my post on Square Foot Gardening 101: Part 1 click the link below.

 Square Foot Gardening 101: Part One

Before we get started I have a few tips to make your gardening experience just a little easier.



  1. Create a garden binder, store your garden plans, ideas and seeds in it
  2. Hand draw a grid of your garden on paper and make a couple of copies
  3. Figure out what you want to grow and how much of it you want to grow
  4. Purchase seeds or transplants and read growing details on the back of the seed packets or on the transplant
  5. With a pencil right down on your garden grid where you are going to be planting what you’re growing
  6. Keep in mind when placing your plants you want your larger plants in the back and smaller plants up front.

This will help you stay organized. It will also keep you from buying supplies and materials you do not need. Gardening can get costly so make a plan! It doesn’t have to be exact but it will be a  good reference along the way!


SFG is based around a 4×4 (16 sq ft) bottomless box  made of wood, stones or bricks. It has an attached weed cloth to the bottom of the box  and is filled with prepared soil also known as “Mel’s Mix.” With an attached grid for simple and organized planting and growing! 

Like I mentioned before, if you’re interested in reading the book on SFG. I highly recommend it! It is called All New Square Foot Gardening by Mel Bartholomew. It’s a super easy read and packed full of information on SFG.


My goal here at Carolina Grown and Grub is to break down the basics of SFG. So for y’all who don’t have time to read a full book on the subject can refer to my blog and get those veggies from the backyard to table ASAP!


You don’t have to build a standard 4×4 box but it is recommend. It’s easy to move if needed, 4×4 boxes are easy to work in and maneuver around. They are uniformed, tidy, and other features such as trellis, arbors and protective coverings can be added to them easily.

Also, you can pretty much grow anything in 6″ of soil according to Mel’s theory and from my experience he is correct! I still have people argue with me about this on the regular basis. So if you feel you want a more depth go ahead and waste your money on more soil and lumber but I promise you don’t need it! 6″ of soil does the trick!

There are three things he does recommend  8″ -10″ of soil for. Those being potatoes, carrots and root veggies. He recommends building one separate box that is slightly taller and deeper to accommodate those vegetables. 


The theory behind SFG is being able to grow a large amount in a minimal space. With little upkeep, no weeding  and no fertilizing! No worrying about pH, texture or drainage of your soil.

In the book Mel has a large section dedicated to what he refers to as “Mel’s Mix” this is the prepared soil you will be putting into your beds.


1/3 Peat Moss 

1/3 Blended Organic Compost 

1/3 Vermiculite

Here is the thing… If you’re going to skimp on any part of your Square Foot Garden DON’T let it be on the soil! This blend of soil requires some money up front but it saves you money  and time in the long run.

How you ask? Well, you never have to replace Mel’s Mix, you only have to replenish your compost after you harvest each sq ft. You won’t have to buy fertilizers for your plants or chemicals to regulate your soils pH.

So, in the book there is a whole chapter dedicated to this soil. It covers what each product is, what service each provides in the mix and the math equation to properly figure out how much you need for each box depending on its size and shape.

I am going to give you the amount you’ll need to correctly fill ONE 4×4 box. This doesn’t have to be exact it is a round about estimate but use your best judgement to make sure you are using 1/3 of each. We are mixing soil here people … not baking a cake!


Spend the money and the time up front and I promise you will be more than pleased with the results in the long run!

Here is what you will need to get your soil started…

This supply list is assuming your only making ONE 4×4 box. Double accordingly to how many boxes you plan on making!!

Supplies for Soil: 

1/2 of one large bale of peat moss

6 small bags or 1 large bag of vermiculite

5-6 bags of compost, three to five different kinds  of compost (ex. mushroom compost, black cow compost)

TIP: Like I said this is not exact, this is a rough estimate and in the past this is what I use to fill ONE 4×4 box. In the book Mel’s math equation equals 8 cubic feet of Mel’s Mix to fill one 4×4 box if you want to get technical.



Supplies for 4×4 box:

four- 4ft 2×6″ boards

six – 4ft lath boards

weed cloth

coarse thread wood screws

power drill

mel’s mix

staple gun


TIP: If you don’t have a wood saw at home to cut your boards in half, you can get them cut right in the lumber section of your home improvement store for free!


1. Begin by making a square with the four boards.

2. With your drill and coarse thread wood screws, drill the screws into the boards end to end until your frame is attached. Using 2-3 screws on each end.


3. Once your frame is secured and assembled move the box to your desired location.

4.  Lay your weed cloth over your box and using your scissors cut the weed cloth to the correct size.

5. With your staple gun staple the weed cloth along the frame and flip your frame so your weed cloth is laying on the grass.


6. Now you are ready to fill your box with dirt, add Mel’s Mix until the bottom is covered then water your dirt so it is moist. Do this until your box is full.

TIP: I place about half of the peat moss, vermiculite, and compost into the box and mix it VERY WELL with my hands then I slightly moisten the dirt mixture with water and repeat until my box is full. Oh, make sure you have some garden gloves this part can get a little messy!

7. Add your lath boards to create your grid. You should have 16 sq ft when finished. Use your drill and screws to secure lath boards to frame and each other.

TIP: Grids are a must! It is not a square foot garden without a grid! This grid system is what is going to make your planting and growing organized and simple! Mel breaks down exactly how many of each veggie, herb, fruit and flower you can grow in each sq ft. Wood lath is inexpensive and can be found at any home improvement store. It is usually already four-foot. If not your home improvement store will cut it for free!


Now your square foot garden is done and it is ready for planting! You will be pulling beautiful veggies and herbs out of your garden in no time!

I hope this post helps you along your Square Foot Gardening Journey! Here are some of my other posts on SFG you might find helpful!

Sowing Seeds 101

 Square Foot Gardening 101: Part One

Square Foot Plant Spacing

Grow it. Pick it. Cook it. Eat it.



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