SqFtGardening on a deck?

There are only 2 places in my yard that get full sun: one is the farthest spot from the house and right at the corner of my driveway and street front. The hubby has put his foot down and said no way to me putting in a veggie garden there . So I am left with my other location.... my deck. Our house is a raised ranch with a glorious deck on the back of it that gets full sun all day long. So much so that we usually can't use it. I have grown tomatoes relatively successfully in huge pots in the past, but was frustrated with how few plants I could get going out there not to mention how much of a mess it is.

My current idea is to build a couple of SFG boxes for my deck. My question is this: Without actually putting my boxes on full legs to create waste high tables, does anyone have any thoughts on the best way to raise the boxes off of the deck to allow for air flow and drainage so that my deck isn't damaged by the boxes sitting on it? I was thinking of simply creating a + out of 2x4's to go under the middle for center support and then L's for the corners. Thoughts, ideas, suggestions?

Also, in Mel's revised book he is adamant that a 6" depth is all you need. For tomatoes in Atlanta is that true? I understand that I would have to water them once or twice daily during the worst part of our summer, but is 8, 10, or even 12" more practical for our heat zone?

Any thoughts or suggestions would be awesome!

How about a brick in each corner to set the box on? Is the deck fairly level or would you need to have legs of different lenghts to compensate?

One concern, these boxes will be heavy and might be a structural issue for the deck. So going more than 6" could be a safety issue as well.

Pete

My deck is relatively new and VERY well built. Also, they would be put almost against the house so the weight would be on the house attachment, which I can assure you isn't going anywhere.
Also, according to my sister (a civil engineer) regular soil weighs 162 lbs/cu ft, but since I'll be using Mel's mix it won't be nearly that heavy.

The deck is very even... I hadn't thought of bricks. That would save me a lot of work and are easy to get. I'll find a pic of our deck and post it so you can see what I am thinking of doing.

I have seen a few pictures online with square foot gardens on decks, and some have legs some don't. But I agree with garden_state with the bricks or even landscaping stones. As per the structural issues, there are code requirements for decks, and they have to be able to bear weight very well, I'm not sure it would be a huge issue. Plus, Mel's Mix and soil weight I'm sure is very different. I'm using good soil not the mix, and I know the mix is a hellofalot lighter.

One thing to think about (and I'm sure you have), is not doing a 4x4 or even a 3x3, maybe make it more like a 2x(insert length), and one way to get around putting bricks down, put some casters (wheels) on it to be able to move it around the deck if you need to (one person here has done just that, and the self-watering raised beds that I have have the option to add casters to them to move them around wherever).

There are plenty of options for gardening. Make use of your rails as well. You can build or buy some really nice rail containers that don't hang on either side, but actually rest on top and go down both sides to distribute the weight better (some are even self-watering). You could do mini carrots, radishes, leaf lettuce, herbs, or some tumbling tomato plants that I've read and heard are perfect for just that application.

The one thing that doesn't seem to grow well for me in raised beds are Deter. Tomatoes (I live in Charlotte, NC) they just always seem stunted, so I would stick with the Inters (unless you have had success with D's). You could even maybe add something to the railing that can be removed to turn it into a trellis for vining plants to make it look cohesive. As for the tomatoes or any tall plant, I fully agree and know that plants can grow in 6" of soil/mix, but for my peace of mind, I prefer 12" for tomatoes and corn. I just feel better about it.

The one thing about me is that, if it doesn't look pleasing to the eye for me, I know I won't like it. So while I look for cheap, I'm not above spending a few extra bucks to make sure that it's visually pleasing to me, and everyone else who will have to see it (like my neighbors. We have a HoA, and I don't want to piss them off).

To para"quote" Bill Nye the Science Guy "If it doesn't look good, I won't do it."

I live near Chattanooga and I would never try to grow tomatoes in 6 inches of soil here unless I didn't have a better option. It seems like you would have to water constantly. Also, it is so nice to be able to plant them deep and let them grow huge, supporting root systems. I were you I'd stick with the big pots for tomatoes and use the square foot beds for everything else. Either way, I bet you'll love having your garden so handy!

Probably there is someone with more experience who will say 6 inches is just fine. I could be wrong. I havent' tried it.

I pulled out my very dusty estimator's hat and ran some calculations on the potential weight of Mel's mix:

Vermiculite 40 lbs/cft
Compost 60 lbs/cft
Peat Moss 38 lbs/cft (moist, not saturated)

This works out to be 46 lbs/cft. The largest box I am thinking of would be 18" by 5' which holds 4.5 cft of soil, and would weigh roughly 217 lbs before plants. This in turn works out to be 43 lbs/ sq ft. So that takes weight off the table. Which also answers part of my original question; would I need a center support? I don't think that I would.

I love the idea of putting them on casters, Kimber. I had thought of that as a passing fancy, but decided that it would weigh too much for that. HA! Now we know it should work. Maybe I'll put my smaller boxes on casters to experiment and can add the casters to the bigger ones later.

Calculations look good, 4 heavy duty casters should work fine. Don't forget the weight of the water.

Hi,

Claire introduced the idea of sfg on wheels to the forum last fall. She has a few pictures in her gallery.

https://squarefoot.forumotion.com/gallery/Personal-album-of-mckr3441-cat_u162.htm

I must buy a different kind of vermiculite than you do. I buy 6 cubic feet bags and can pick pick them up with my thumb and finger. You can find some threads from 6-8 weeks ago where we agreed that a 4x4 box was in the 250-300 pound range when the MM was saturated. We also decided that the important thing was this: we could safely put a 4x4 box any place we would put 2 adult men! YMMV

I use 4x4 with HEAVY duty casters. You could do just a foot tall, with casters.

boffer wrote:Hi,

I must buy a different kind of vermiculite than you do. I buy 6 cubic feet bags and can pick pick them up with my thumb and finger. You can find some threads from 6-8 weeks ago where we agreed that a 4x4 box was in the 250-300 pound range when the MM was saturated. We also decided that the important thing was this: we could safely put a 4x4 box any place we would put 2 adult men! YMMV

I researched the weights online and pulled the info from manufacturers, etc. The weights may be off by a bit, but the important thing was to establish that it was something my deck could handle so I could show the numbers to the hubby who is very skeptical about this whole idea.

I'm going out this morning to buy the 2x6's and soil mix. I'm WAY excited. Hopefully I can get a good portion of it done while my little man is taking his naps today. I'm hoping to have it ready for planting by Monday at the latest.

Mel says that 'closies' are good enough in SFG, and I have always taken that to heart. What I was suggesting is that your vermiculite weight is way off. At 40lb per cf, there would be very few people on the forum who could pick up a bag of vermiculite. Your box will be lighter than you figured!

But the bottom line is what's important: your husband understands that the weight of a sfg box won't hurt your deck. Have fun building today and happy gardening.

YAY! I'm glad your hubby is in supportive!

I know my 3 cf bag of vermiculite weights less than my 3 year old, I am betting it weight like 20lbs?

I wonder if the weight given was pre expanded?

dont forget pictures!

Hello, fellow Georgian! I am a little below Atlanta, and my tomatoes are doing great in their 6" of soil. I "layed them down" like Mel says to in the book. Last year, I had them in 8", but this year I had to take apart the old garden (made with bricks and wicked away all the moisture, bricks kept coming unglued and falling over, etc etc etc) and re-build it with a different material (cedar) that happened to be only 6". It turns out that you really do only need 6" of Mel's Mix! Tomatoes are doing great - Juliette and Mr. Stripey. I also have a Cherokee Purple that is doing good, not great though. Cherokee is recovering from some kind of wilt or something, but he is getting better every day with the extra attention I am giving him! I water them almost every day. I check the weather channel website for the gardening forecast, and if the watering need is "very high," I know I need to water that day. It's been so hot and muggy here!

You can see the Juliette Tomatoes in the background.

One type of design you can build is like saddling a horse. Build two boxes 2' x 4', closing the bottom, and bridge them together, leaving a space the width of your deck railing, if you have one. Then proceed as usual with your soil mix, and two grids to fit. You must make sure the fit is tight, because you will be dealing with a balancing act between the two boxes.

Another rail design that you can use is to build a planter box that installs on top of the railing. I am not sure if you have a railing on your deck, or if it is open perimeter.

There is also a post in the forum about weeping boxes. You should search for that.

I've grown tomatoes for the last two years in my SFG's. This year I grew them in deeper soil and they seemed to do better and maintain good health longer into the season. Next year I'm going to try adding mulch every couple of months because I think the gradual weakening of the plants as they grow is due to their heavy feeding habit, and I'd rather keep the soil happy and healthy than add fertilizers. I'm also try BIO's, so we'll see how it goes

We are planning to use a modification of the Topsy Turvy system for growing vines. You can use a five gallon bucket by drilling a hole in the bottom, and using a sponge to anchor the plant. Then you fill the bucket with Mel's Mix, and plant some herbs, spices or other type of produce that is compatible with the amount of water required to raise the tomato plant.

That should work pretty well for determinate tomatoes and small vines, David. Great idea! Be prepared to do quite a lot of pruning (or letting it sprawl) if you plant something big, though!

For most herbs, though, you might get more mileage out of planting out of the top of the 5 gallon bucket, simply because you'll have more surface area and be able to grow more things.

Another option -- a friend gave me some planting bags (forget what they are called) this spring. I haven't tried using them yet, but basically they are a lot like Topsy Turveys, only made out of heavy poly material (like a really thick garbage bag). They have pre-punched holes in the sides to allow for multiple plants. I was going to use them for my strawberries until I decided they weren't the loveliest looking things in the world, and went with a terracotta jar instead. Still, I think it would have worked well. And the plastic is black and thin enough the sun would have helped warm the soil.

Megan wrote:a friend gave me some planting bags (forget what they are called) this spring. I haven't tried using them yet, but basically they are a lot like Topsy Turveys, only made out of heavy poly material (like a really thick garbage bag). They have pre-punched holes in the sides to allow for multiple plants.

I use these to plant impatiens and the bags create a huge vertical display. I like them a lot.

Are they hard to water?

nope

Maybe you I could use them as a liner in my bucket. Better yet you can determine the gallon capacity of the bag, then make a "bucket out of rabbit cage wire. How would that work?

The bag doesn't need a cage, it's a standalone. I was concerned about how it would look, but apparently that's not a problem.