SFG Depth

After five years my raised box rotted and I am preparing to build another one.  The old box sides were two 2 x 4's (7 inches) screwed together.  I plan to use either a 2 x 6 or a 2 x 8 for the sides on the new one.  Do you think a 2 x 6 would give me enough depth or should I go with the 2 x 8?  I plant tomatoes, bell peppers and cucumbers.
In the winter green onions and cauliflower.  Guy

6" is the tried and true SFG answer. The only disadvantage to 8" is that it's more money to fill the boxes, and you don't need it. But it won't hurt anything.

Keep in mind that your mix will settle somewhat, at least the first year, so you'll need to add more anyway. At least that's been my experience.

I use 2x8" lumber to allow for settling of the Mel's mix. It also allows me room for topdressing with compost during the season.

I'm actually just built three new small beds (2 - 3'x3' and 1 2'x5'), I used 2x6s stacked two high. Which gives me actually 11 inches in depth, but I've set the boxes into the ground 1 inch and intend to top with 3 inches of mulch with about 1 inch left to the top of the box. I wanted the depth for aesthetics in the yard with planters and the mulch to combat the drying issue I have in the the other 6 inch bed.

In my experience, the 6" dries out fast. The deep rooted plants don't seem to thrive as well. The shallow rooted plants lettuce etc seems to do "OK", got some nice radishes. Overall tho, in my experience, I'd say the 6" is too shallow. Are your beds going to be open on the bottom or covered?

My box will be raised with a plywood bottom.  I am going with the 2x8 sides.  Thanks for your suggestions.

Bed walls a little taller than you need for root growth might be a good thing. In the small area I have for planting at my own home, I've found mulching with wood chips hugely helpful this summer, when we've had record-setting stretches of 100+ temps. Plants that had been wilting stabilized and started looking good again. Mulching may help insulate any fall crops I try to grow at my house against early snows, too.

Most of my garden is in my neighbor's yard, where he has lots of raised beds. Almost all of them have gotten so full of soil and compost over the years that any water running over the soil's surface before settling in can run right off the top of the beds and out of the boxes. Any mulch I apply can zip right along with it onto the pathways between boxes. The boxes have effectively no "lip," or containment, at the top.

So it seems to me that ideal box height is about leaving room for mulch as well as for roots.

Marc Iverson wrote:Bed walls a little taller than you need for root growth might be a good thing.  In the small area I have for planting at my own home, I've found mulching with wood chips hugely helpful this summer, when we've had record-setting stretches of 100+ temps.  Plants that had been wilting stabilized and started looking good again.  Mulching may help insulate any fall crops I try to grow at my house against early snows, too.

So it seems to me that ideal box height is about leaving room for mulch as well as for roots.

Guy,  Good decision.  I'm a 2013 Newbie.  My limited experience is that 6 inches of quality MM is all that is needed for the root depth (exception of root crops like carrots, parsnips, etc..  But extra height for 1-2 inches of mulch means a minimum of 7"+ actual inches of bed sides.

Hi all,

so just to clear up my own confusion.... I just put in two new beds, 4 x4  the beds are 12 inches high but the soil measures about 6 inches deep (new MM)  .....  I did not "double dig" down and I lined the bottom with wire and with garden fabric because I have lead in my yard soil and  lots of
groundhogs.... so is 6 inches of soil enough for tomatoes, corn, cucumbers, eggplant....?

thanks!!!!

Hi Shegardens.  Yep!  And that 12" gives you room for large carrots, potatoes, mulch...

Have fun!

Shegardens, Six (6) inches is all that's needed for everything except for long roots (carrots, parsnips), potatoes, asparagus, etc. You can add a top hat to just those squares.

FWIW- in our area it gets so hot and dry that I found it hard to keep my original 6" bed hydrated enough.  When we re-made the beds three years ago, we made them all 12" deep with 4" under ground and 8" above.

The disadvantage is the cost to fill them, but that's a one-time expense.  The advantage is I can plant potatoes, carrots, etc. anywhere without having to worry about making "top hats".   We've been planting a little over 1/3 of the garden in root veggies so it seemed to make sense.

Thanks All!

and what is a top hat?

I did order a few more MM bags just to fill in a little for the carrots...
its expensive, but I'm hoping this is it.... I've redone the whole garden and
am almost ready to plant!

Really appreciate everyone's guidance!

Top hats:  I didn't realize that there were no topics titled 'Top Hat'

It's basically a way to add on vertical space. 

As Sanderson showed you, you just make another 6" box to go around 1 or 2 squares (or as many as you want.) 

We have a top hat around 16 squares at the bottom of our garden plot for our long carrots & potatoes. 

(This shot is from the gate.)

So Nice!  Thanks Sanderson and AtlantaMarie!!!
 
Now a whole new world of possibilities! 
What beautiful boxes you have!
I'm impressed with the thickness of your wood...
mine is pretty thin, I'm hoping I'll get some good years out of it,
but I'm a little concerned, esp. after the investment in good MM....
I tried (for a while to post a pic) but it just won't upload ....
will keep trying...

See how big the file is.  The best file size is 150kb or less...  You can open the photo with Paint or some similar program and resize the photo if necessary.  Then it should upload much easier.

(Can you tell I had the same problem, lol?)

Thanks AtlantaMarie,

I tried a few more times, and the file is pretty small, but it tells me that I have an incorrect passcode (I reset it and that didn't work either) or it just keeps reprompting me and resetting once I hit the upload button....
so I'll try again a bit later....
thanks again