How to Build a Raised Bed Vegetable Garden: Step 2 - Let's Talk Dirt!

Okay, so we've been talking vegetable gardening this week - specifically Square Foot Raised Bed vegetable gardening! In case you've hit this link off of Google, or are just now poppin' by, here's a recap of the previous links:

Update:

Step 1: Build a Box
Step 2: Dirt Mix (you're here!)
Step 3: Add a Grid (for Square Foot Gardening only)
Step 4: Planning the Plants

My (almost) 1 Month update
Fertilizing
Pest Control

Coming Soon:

Managing Fungus

First, let's also recap a few of the previous links I've published.

~For a general vegetable gardening primer with the basics for your vegetable garden site, soil fertility, garden tools and buying plants, click here.

~Basic information on wood and a good soil mix go here. (scroll down about halfway)

~For my site selection dilemma and a little bit of inspiration, click here.

~And more about the importance of site selection, click here.


Now, we move on to Step 2 - The DIRT!!

We've built our box or boxes, cleaned out the weeds and grass from the area we want to site them, laid out some landscaping fabric and leveled our boxes.

First we are gonna trim out the edges of the landscaping fabric.

You can use scissors, but I think that box cutters made for a super easy job of it. Just carefully slash around the box to trim away the excess. This is strictly for aestehic purposes so if it doesn't bother you, you could also leave it instead of trimming it.

Once you've trimmed out the fabric, lay down a tarp close to the garden box. You are going to start to mix your soil on the tarp and you don't want to by-pass this step and try to mix it right into the box. Just trust me on this one, or you'll risk tearing your landscaping fabric. This is actually an old shower curtain that I saved for just such a purpose as this!

For the soil, I wanted to try to follow Mel's Mix,which is 1/3 peat moss, 1/3 vermiculite and 1/3 blended compost from 5 separate sources. Basically that just means that you should combine 5 different forms of compost for your 1/3 - from your compost pile, from different types of manure, humus, mushroom compost, worm castings, soil mixes and boosters and such.

Some people like to use perlite instead of vermiculite, but Mel doesn't recommend it, use it or like it. It's hard as a rock, coarse and gritty, and does not hold moisture like vermiculite does.

Unfortunately, Lowe's didn't have much variety on compost, and no vermiculite, but I found this Jungle Growth brand of flower & veggie soil mix that contains forest compost, sphagnum peat moss, perlite, vermiculite, horticulture grade hardwood charcoal, lime and 1:1:1 fertilizer. I used 2 bags of that (4 cu. ft.) per bed as part of my mix. To that I added peat moss, humus (or a bag of mixed compost), and some good old Black Kow cow manure. It wasn't a perfect Mel's Mix, but with the Jungle Growth stuff, I think it came close. The complete mixture I used is listed at the bottom of this post.

UPDATE NOTE: Unless you want to have to water your raised beds every single day, and where I live in the Deep South, sometimes twice every single day, do whatever you have to do to find the vermiculite. The amount of vermiculite in the Jungle Growth is not enough to keep the moisture in the dirt! At least that is what I am finding for my region. The beds are quickly drying out with the heat of the day and it's not even summer yet! So, hunt it down! It is important!

First, I poured one bag of the Jungle Growth soil mix out onto the tarp.

Add the Black Kow manure on top of that.

Top that with some humus, or other compost source, and 1/2 of the bag of peat moss. Be sure that you are standing up wind of the peat moss and/or you are wearing a mask, because it is extremely dusty. To make it easier, you could either pour a little and then lightly spray it before adding more, or you can simply pour some out, mix it in, and pour some more out.

Carefully toss it all together on the tarp. If you have two people, you can each grab a corner of the tarp and just sort of slowly roll it back and forth to turn it . Once mixed up pretty good, get somebody to help you lift the tarp and transfer the mixture into the box.

Now remember, I picked up the 8" boards instead of the 6", so this mixture up to this point is a bit short even of the 6 inches. This is where I decided to add in another bag of the Jungle Growth mixture. I then carefully used a shovel to turn it and mix it in, taking care not to dig into the landscape fabric underneath. Then I used very small plastic garden rake to carefully rake it out. This still does not bring the mixture to the top, but I figure I have about 7 inches in the box now and since I only need 6 inches, I'm okay with it being short.

The difference is going to affect how you'll finish off the grid for square foot gardening. If you have 8 inch boards, and want to completely fill the box, to save some money you can put some sand in the bottom of the box before adding in your soil mixture, but you'll want to take care not to mix the sand up into the soil. Our soil is ready!


Here's the mixture I used to bring ONE 4' x 4' x 8" box to near full. I think this mixture should fill a 4' x 4' box of 6" height.

*2 bags (2 cu. ft. each) of Jungle Growth Professional Flower & Vegetable Soil Mix (available at Lowe's - blue bag)
*1 bag (50 pound) Black Kow composted cow manure
*1 bag (40 pound) peat humus or other source of compost
*1/2 bag (from a 3.8 cu. ft. bag) of sphagnum peat moss

UPDATE NOTE: Unless you want to have to water your raised beds every single day, and where I live in the Deep South, sometimes twice every single day, do whatever you have to do to find the vermiculite. The amount of vermiculite in the Jungle Growth is not enough to keep the moisture in the dirt! At least that is what I am finding for my region. The beds are quickly drying out with the heat of the day and it's not even summer yet! So, hunt it down! It is important!

Now, the GRID!!