Mobile Veggie Garden

The sunniest area in our back yard is right up against the garage door..
But we couldn't plant a veggie garden there, so I felt the next best thing would be a movable cart!

I liked the idea of catching and reusing the water it would consume.

I liked the idea of being able to move it around - in the shade on a super hot day or into the last bit of sun in the late afternoon..

I had several ideas for it, including a metal frame.. 6 pneumatic wheels.. a road train with several trailers.. sun shelters.. a rain catching roof..  a green house.. areas to hook tools..

In the end, this was the quickest I could come up with and we were eager to plant as it was getting late in the season..

Step 1: Parts List

Tools:
electric drill and philips driver bit
belt sander
saw bench
jigsaw
sanding block

Materials;
-1 sheet of 2.4m x 1.8m construction ply
-1.2m x 38mm hardwood dowel
-5 x 2.4m x 4cm hardwood garden stakes
-self-drilling wood screws
-2 x plastic wheels
-two sets of billy cart 1/2 inch axles
-exterior grade wood glue
-weatherboard grade silicone gun
-outdoor primer left over from painting the shed
-outdoor paint left over from painting the shed

Update:
-I forgot to mention I used pond paint sealer to seal the inside. Please report back if you find something better!

Step 2: Preparation and Construction

I cleaned up the garden stakes a little with the belt sander. Taking off rough edges.

I used the garden stakes as an internal framework, giving the box some extra strength.
They were cut and used as a brace in all internal corners of the box.

I cut the ply into pieces with the saw bench, giving me parts for a box that was 2m long x 1m wide and 40cm deep.

These were the rough dimensions I kept seeing in gardening books for "a garden bed" and since this was all I was going to have, I figured I should make it as big as possible.

At one end cut the corners out of the main panel and ran the garden stakes right through the panel, creating legs for the handle-end of the cart.
The initial construction pictures don't capture this well. There are more of the legs later.

All joins were glued and screwed.

Step 3: Adding Framework for Wheels

I had some offcuts of plywood, but nothing substantial enough to make a frame the size I wanted, so I cut several pieces the same size and glued them together, adding a few screws to provide extra strength. (see picture 1 and 2)

The wheels were attached by gluing the frame and screwing down into it through the base of the box.
(see picture 3)
Note: picture 3 also shows the legs of the handle end of the cart.


I then began filling in all of the screw holes so that the paint would have a nice smooth surface to run over and not create any areas to attract moisture over time. I couldn't find any decent exterior grade wood fillers, so I ended up using sawdust and exterior grade wood glue.
(see pictures 4 and 5)

Step 4: Adding a Handle

I cut the end off our old mantle piece (it was just asking for it, sitting in the back of the garage there!)

The offcut was about 40cm x 20 cm by 4cm thick.

I cut it roughly diagonally and drilled holes in the thicker end of each piece.

I screwed the pieces of mantle piece to the cart and slide the dowel into them.

Step 5: Painting

I used weatherboard sealant-grade silicone and ran a bead along all internal edges.
(I couldn't find any decent fillers and this was supposedly good for sealing against wood).

I then painted a white primer inside and out and finished with two coats of exterior grade paint.

Update:
I initially forgot to mention that I have used several layers of clear pond paint on the inside.


I'll try to summarise the details:
I had Pond paint left over from a fish-pond-in-a-wine-barrel project that I never used it for (turns out the fish were okay in wine-soaked wood and the wood in the wine barrel expanded enough to hold water!).

The pond paint container lists it as non-toxic and suitable for constant exposure to wet areas.
I wasn't 100% convinced that it was perfect or perfectly safe to grow veggies in, but a> I had it sitting there and b> I didn't find any better alternatives for looking.
Similar commercial applications I found used tar to seal wine barrels. Tar doesn't smell great to me, so I can't imagine it being great for your food to grown in.
Thanks to MikeyNCat for reminding me to post this update.

Step 6: Drain Hole and Tap

I then drilled out a drainage hole and added some small gauge pipe with thread.
(see pictures 1, 2 and 3)

Before filling with dirt, I put some excess weed matting I had from another job inside.
(see picture 4)

Step 7: Adding Dirt and Plants

I used the no-dig gardening method to fill the cart.

I figured it would be lighter and provide plenty of organic matter.

There is a lot of internet information out there on this, so I won't go into it other than to say I used something like:
a layer of lucerne
a layer of fertilizer
a layer of pea straw
a layer of fertilizer
a layer of dirt and compost
a layer of sugar cane mulch

Step 8: Final Thoughts and What I Would Change, What I Would Add...

It worked pretty well, plants grew and we were happy - but there were a couple of issues and things I would change.

It is heavy-
So heavy in fact that the rubber on the first set of wheels I bought (rated at 70KGS each) ended up warping off the wheel. The rich soil holds a lot of moisture - good for the plants but bad for your back.

The drainage hole is good and allowed us to capture and recycle the water, but..
Beware that dirt, compost and fertilizer creates a pretty potent brown liquid that is very smelly and attracts flies. BUT.. you can dilute it and reuse it. Saving that precious water.

I very quickly added a tap so I could control when/how it was drained.

If I did it again, I would make it shorter and possibly narrower. Say 1.5m x 80cm.
This would fix issues with weight.

I would change the design so the wheels were larger and on the outside, rather than underneath - making them more of a feature than an afterthought.


By the way, I always had some other ideas to add to the cart, but have not yet put them into play:

A frame work over the top to assist with netting (to protect from birds) or a tarpaulin (to protect from the sun or heavy rain).

Fold out side tables for potting, picking or your cup of tea.

Tool hooks for holding tools while you are working.

Comments

[tim_n]

It's a great looking cart - doesn't look like the ply has quite enough support for the weight but inspiring none the less - I may do something like this for my garden :)

[Lorddrake]

what about adding hinged feet to the cart so that they can swing up out of the way while you are moving it around, but once you have it in position you flip the feet down to bear the weight of the planter to take the stress off the tires

just a thought.

[menerell]

It's so cool it made my imagination fly!
While reading i was asking myself... would it be possible to adapt it in order to carry it with a bike? How much does it weighs?
I also tought it would be possible to make a greenhouse light structure with camping tent curved sticks.
And just a pair of wind and it will cross the sky!

[farmsteader]

very good project, question when you use metric and imperial measurements it is confusing , i can estimate the sheets of plywood at 4x8Ft ? what thickness, if i go into our local hardware store , and ask for metric size not sure they would know off the top of their head. These insructibles are written to make things easier right ? (yes i know folks from around the world read and use this fine site, so write both then )this is why i brought it up, but thanks again for this usable project , we have been looking for something separate to grow herbs or other veggies in, or an outside utility sink,having a hard time finding a used one.

[lofgren]

Most vegetables don't grow deeper than 15inches, so that is the one that counts
(I did a web search to convert it - hint, hint).

Other than depth, make it smaller than my measurements, use thinner wood - save yourself some money and it will be easier to move ;)

Failing that, and you want to use my measurements exactly - try "the google".

[archerj]

I've been wanting to do this, and haven't had time to design it--and now you have done it for me! A raised bed is a necessity here in South TX since we have a long growing season and weeds grow faster and taller than anything else. So thanks for the instructions.

[TossManual]

Nice idea.  What is lucerne (besides a city)?

[imajem]

Another name for the plant alfalfa.

[lofgren]

Hrm.. perhaps a common crop in Australia but not elsewhere?
Here's a quick link I found:
http://www.dpi.qld.gov.au/26_3445.htm

Described as a type of hay here.
It is basically straw-like, initially provides good drainage and breaks down to provide good organic stuffs like nitrogen.

[gaiatechnician]

I think some sort of water trap on the legs would be a good idea to stop insects and slugs from crawling up it.  Or anti bug  goo, or goo + copper wire.
I have wanted to make something like this for a few years but still have not done it. 
I thought something that you could move using a dolly or hand truck.
I do not think wheels on the thing are necessary
For sure, soil is heavy!
Brian

[lofgren]

Yep, had similar ideas for bugs and a few others - I like yours! :)

I was naughty and cheated a little. I spread a few snail pellets around the legs and wheels (since it wouldn't leach into the dirt the veggies are actually growing in).
An alternative is to place lemon in an aluminium pie dish. The lemon attracts snails and the chemical reaction between the two apparently kills them..

Thing is.. snails and crawling bugs turned out to be the least of my worries!

The veggies were assaulted from the air by:
-cabbage moth (that laid dozens of eggs that became green caterpillars),
-the green shield bug (a sap sucker that crippled my tomatoes in the early stages of growth),
-aphids,
-white fly and
-mites.

I regularly applied Yates organic products - Natrasoap, pyrethrum and another product called EcoOil. (Perhaps the source for another instructable!?)

Thanks for your comments.

[MikeyNCat]

Painting the inside was a bad idea. Paints release VOCs (Volatile Organic Compounds) and they will leech into the soil, then into the plants' root system, and finally into the fruits of the plants that you will then eat, releasing the VOCs into your body.  Using the silicone sealant was a bad idea for the same reasons, but the silicone gives off most VOCs during the curing process. I would suggest building the box with UNTREATED lumber and do not apply any silicone or paint it. Also, making two square boxes instead of one long one would eliminate the stress issues and make the garden much lighter and more manueverable. If you feel you have to seal the cracks, use beeswax as a safe alternative to the silicone. The mobile garden idea is great, it would also allow for transport into a garage if a cold snap comes, allowing gardeners to protect their crops and extend their growing season.

[lofgren]

Bah! I typed out a massive reply on my phone that did not submit properly :{

In short, I had those concerns too, but the end result was a compromise.

The cart actually has clear pond paint on the inside and I will update the painting step to reflect this, but had not got around to it. I missed it in an attempt to make the instructable brief (compared with my entertainment unit).

To explain further..
I wasn't convinced that pond paint was 100% safe, despite the "non-toxic" claim on the pot. But figured I had some spare and it was safe-ish compromise between chemicals and longevity for the cart.
Why bother building something that is going to rot in a season?
Yet, I was very aware of "treated" woods, which is why I went with raw construction ply, which was coated in nothing (yes, the middle layers contain glue).
I plan to empty/check/reseal every couple of seasons.

When I got to the painting stage in construction I looked about to see what commercial applications are doing. The few I found that sell half-wine barrels pre-potted with veggies or herbs actually seal them with tar...
It may be the safest thing out there when analysed, but the smell doesn't seem so wholesome to me, so I steered clear.

The reasons for sealing are longevity and the ability to capture and reuse the water (or as more accurately described by balloondoggle- "compost tea").

I thought there would be nothing more miserable and wasteful than watching water leak from the thing like a sieve - we are in a drought here in Australia. That and the fact that water sitting in those leaky crevices will only accelerate rotting.

As for size; yep, smaller obviously = more manoeuvrable.
I had many ideas and considerations when building (see the intro and last steps for details). In the end, I went with a larger cart so that I could plant more, sooner.

We were excited about a recent discovery of heirloom veggies (having become disheartened with the tasteless, colourless produce transported half-way round the world to our local supermarkets).
The rush - it was late in the season, so we wanted to get some stuff planted before it was too late.

But, my friend, you have the benefit of my hindsight!
So make your carts earlier in the season, build them smaller, put bigger wheels on them and since you are going out to buy supplies beforehand, seal with beeswax :)

[lofgren]

[b1russell]

How really, really COOL!  Maybe, if it's mobile, Mom won't object so strenuously to veggies on the south side of the house (front yard!).  Not that we have SUN issues here (it's Phoenix), but her roses occupy most of the north (back) yard! Thanks a bunch (of carrots).

[itwasalan]

Very clever. 

[ChrysN]

Great idea!

[RelientOwl]

Yeah if you made the wheels bigger it would be easier to move around

[balloondoggle]

 Besides beefing up the wheels, consider centering them on the cart.  That way you can put more effort into moving and less into lifting.  I like Juggsy's swivel caster idea, too.

I really like this idea over what I currently have - a too-large plot overrun with weeds!  Great idea to capture the compost tea.  I would have wasted a whole season of that before i realized it was good stuff.

[tecneeq]

I agree, the wheels look weak. But i like the idea of a mobile garden very much.