So I built a new garden box last week...

[oleguy]

Made from untreated cedar 2x12s, with 4x4 posts in the corners. It cost me a fair amount of cash for both the wood and the fill, and I have two more boxes I need to replace over the next few seasons (you can see an old one to the left, with the electrical conduit trellis).

So my question to the good folks here is if I over-engineered or perhaps didn't account for something.

The 4x4 posts extend about 8" below ground for stability, as opposed to just resting the box on the surface like my previous ones. I'm not far enough down to be below the frost line in my area (live in the North, 2-4' is commonly how deep it can go), but it's also not attached to my house or is my house, so a little heaving shouldn't be the end of the world, right?

I put it together using #9-3.5" deck screws and attached each of the boards to the 4x4s, 3 screws per board, mostly because those were the biggest deck screws I could find at the hardware store at the time. Is that enough screws to hold back what is about 2.5 cu yds of fill comprised of compost, peat, and black dirt? The box hasn't seemed to bow at all, even after it rained the next day, so I don't think it's too much weight to bear...

Anyway, as I said, this wasn't a cheap project so I want to make sure that this is the right design for the next two before I hand over another $500 for lumber and $500 for fill and materials.

 

[Blain]

You can buy a lot of vittles for that kind of cash.

 

[MadScientist]

IMO, a bit much. One tier (2" x 12" or 1" x 12") would be sufficient.

I got me 2 of these 3 years ago when they were on sale for $80. each. More than sufficient and holding up well. http://www.homedepot.com/p/Greenes-Fence-4-ft-x-8-ft-x-10-5-in-Dovetail-Cedar-Raised-Garden-Bed-RC6T21B/203477958

 

[dphantom]

I agree 1 tier would be enough. the key is getting above ground level where your box soil will warm before the ground even has all the frost out. A second tier really won't gain you much.

 

[avaluna]

1 teir is fine. Use regular spf lumber and it has lasted 3 years no problem. I'll get 5 or more out of it. No posts, just garden stakes pounded in as far as possible and cut off. No frost heave problems.

 

[DrPizza]

To save some money, try just getting rough cut lumber if available in your area. No need for kiln dried lumber. I just did a 16x5 raised bed with 2x12 larch (and actually 2" by 12"), for about 10% your cost.

 

[oleguy]

To save some money, try just getting rough cut lumber if available in your area. No need for kiln dried lumber. I just did a 16x5 raised bed with 2x12 larch (and actually 2" by 12"), for about 10% your cost.

Oddly enough, the lumber yard that sold rough cut was $15 more per 12' section than the big box, and that was before the big box rebate.

And I could have gone with Douglas Fir (the other untreated option in my area)... and maybe should next time given the condition of the box I built three years ago. But a lot of the stuff I can find around me is either treated or is warped, cracked, and twisted to the point that it's cheap because it's not good enough to be visible once construction is completed.

 

[oleguy]

Too all the folks who think that using going up to the second tier was pointless:

I mostly agree.

However, the plot of land my house was built on was subdivided from a larger plot that had been a number of things since the 1920s, none of which had been residential. The soil, if that's what you want to call it, last had on it a set of garages and sheds that held a number of gas and diesel-powered vehicles. City testing prior to purchase and demo of said sheds indicated no over-the-line contamination. Additionally, work in yard had revealed that whoever demoed the prior structures felt that the proper dumping procedure was the just put a thin layer of dirt over it and call it a day.

Digging out the 12" below the sod was more clay and bits of building material that I thought possible, with a lot of chunks of concrete, brick, and asphalt. I have a tarp in the backyard (what I was standing one taking the pictures) that has the original soil. I honestly believe that if I sifted it with 1/2" hardware cloth, I would have half the volume in dirt and the rest would be rocks and building material. I guess that's why we got a deal on the house...

Also... the 2' height (or nearly so) means less kneeling and bending to get into the middle of the boxes.. though I wish I could fill it with a mix of native soil and something imported.

 

[jaha2000]

I probably would have put it together with timberloks instead of deck screws.
Overall, nice looking box.

 

[dphantom]

Too all the folks who think that using going up to the second tier was pointless:

I mostly agree.

However, the plot of land my house was built on was subdivided from a larger plot that had been a number of things since the 1920s, none of which had been residential. The soil, if that's what you want to call it, last had on it a set of garages and sheds that held a number of gas and diesel-powered vehicles. City testing prior to purchase and demo of said sheds indicated no over-the-line contamination. Additionally, work in yard had revealed that whoever demoed the prior structures felt that the proper dumping procedure was the just put a thin layer of dirt over it and call it a day.

Digging out the 12" below the sod was more clay and bits of building material that I thought possible, with a lot of chunks of concrete, brick, and asphalt. I have a tarp in the backyard (what I was standing one taking the pictures) that has the original soil. I honestly believe that if I sifted it with 1/2" hardware cloth, I would have half the volume in dirt and the rest would be rocks and building material. I guess that's why we got a deal on the house...

Also... the 2' height (or nearly so) means less kneeling and bending to get into the middle of the boxes.. though I wish I could fill it with a mix of native soil and something imported.

Well that is information we did not have before. There is nothing wrong with the 2nd tier. It is usually not necessary unless you have some qualifications to making that 2nd tier. As you just did.

 

[DrPizza]

Oddly enough, the lumber yard that sold rough cut was $15 more per 12' section than the big box, and that was before the big box rebate.

And I could have gone with Douglas Fir (the other untreated option in my area)... and maybe should next time given the condition of the box I built three years ago. But a lot of the stuff I can find around me is either treated or is warped, cracked, and twisted to the point that it's cheap because it's not good enough to be visible once construction is completed.

Egads! $15 more per 12' section is more than I even paid - and that was for larch, which the lumber mill only custom cuts - they don't stock any sizes. Various types of pine, maple, oak, etc., I can just drive in, pay, and drive out with my lumber in minutes.

 

[oleguy]

Egads! $15 more per 12' section is more than I even paid - and that was for larch, which the lumber mill only custom cuts - they don't stock any sizes. Various types of pine, maple, oak, etc., I can just drive in, pay, and drive out with my lumber in minutes.

To be fair, I was in a time crunch and was unable to make it to other local lumber yards. But they wanted $80 per 12' board of rough-cut cedar. Menards (where I ended up going) had the appearance board for $65 per 12' board, plus it was their 11% rebate weekend, so it was even cheaper.

It's possible that I picked the yard that doesn't really do much cedar or maybe has a better quality... but it still didn't look much better than the stock at Menards.

 

[thestrangebrew1]

My daughter asked if we could build a garden box and I was thinking of just doing a 3x3' or 4x4' box. Possibly smaller if I could since my yard isn't very big. For tomatoes, maybe some squash, and maybe some herbs. I'm now thinking my prospective box is too small.

 

[cabri]

My daughter asked if we could build a garden box and I was thinking of just doing a 3x3' or 4x4' box. Possibly smaller if I could since my yard isn't very big. For tomatoes, maybe some squash, and maybe some herbs. I'm now thinking my prospective box is too small.

Tomato plants should be placed at least a foot apart.
Squash are a vine, so they can crawl around. A 3x3 box will handicap such considerably.

 

[soulcougher73]

Wow those are expensive. Id probably just use free wood off CL or something if i ever did that. I know nothing about planter boxes so what i just said i would do might be a totally bad idea lol

 

[oleguy]

My daughter asked if we could build a garden box and I was thinking of just doing a 3x3' or 4x4' box. Possibly smaller if I could since my yard isn't very big. For tomatoes, maybe some squash, and maybe some herbs. I'm now thinking my prospective box is too small.

So in our 4'x8' box, we divide it into 1'x1' squares and go from there. For tomatoes, we give then a 2'x2' plot, so we can get up to eight tomato plants in a single 4'x8' box. This year, we went with five tomatoes and filled out the box with six pepper plants, spaced in a zig-zag pattern in the remaining 2'x6' space. That should be more than enough space for them, and hopefully with the extra depth in the box, they can root deep and not get water-stressed so quickly. As far as yield, with eight tomato plants last year, we were swamped and ended up processing a number of them into a puree for sauce-making that we froze. The peppers can be hit or miss... feels like more misses the last couple of years, but again, I hope that's because of the old boxes they were placed in.

As for herbs it really depends, but besides containers (which they take to pretty well), a 1'x1' plot is all they need, even in a box that's only 8" deep. Basil, dill, mint, oregano, chives, tarragon, and thyme all go more up than out. Of course in my part of the world, they are mostly annuals so I have to replant the next year... but even after winters of -20F lows, the tarragon and chives both survived to live another summer, and the mint can easily become an invasive if you put it in a box or ground, as it sends out rhizomes everywhere. I didn't realize this when I planted last year, and now a corner of the box it thick with mint rhizomes, so I might have to rip that whole thing out...

And yeah, your summer squash will fill out a 3'x3' plot pretty well. We usually give them that in a box and they take it all.

 

[thestrangebrew1]

Thanks for the info. I'm thinking maybe just trying to grow a vegetable at time then with the space I have (besides the herbs).