Sunday, May 10, 2009

My Self Watering Tomato Container

Earthboxes are a patented container with a large reservoir. They are available for purchase at most large nurseries. They are nice systems that allegedly increase tomato production by 15%. They are also said to make your harvest nearly one month earlier. Unfortunately, they are pricey. They start at $69 for the box. The tomato cage is x-tra.

Instructions for making your own version of these have been available at Tomato Fest for a couple of years. These instructions are fabulous; with both pdf and video explanations they are easy to follow. My only problem with the design is that it requires the wasting of almost 1/2 of a huge plastic container. That is just too much plastic waste for me to be comfortable with. Today my mission was to make a version for under $25 that had no waste.
The container I selected was a 37 gallon gray rubbermaid for $16. I wanted something a little smaller but they were out of them. I went with it and decided I would plant three plants in it, instead of two. Gray was chosen because black might have cooked the roots.

Earthtainer instructions tell you to cut a separate container in half to make your platform for this container. I deviated from those directions. And decided to use the inner part of the cover for the platform. I used a skillsaw to cut out the whole center following the depressed line around the edge. You have to be careful with this step, go slow and control vibration or chunks will crack off.

Once it's cut out, it fits easily into the container. There will be gaps around the side, but that's OK. We take care of that later.

The next step is to cut a hole for the wicking basket. Your hole should only be about 4"x4". The pond basket I bought for $2.34 at Lowes, was about twice that size, but you still want the hole to be 4x4 or your soil will be too wet. Draw a square in the center of the platform. It need not be exact. Drill a pilot hole and then cut out the hole with a skillsaw.
Next, cut a curve out of the side of the platform to fit the PVC filling tube you will use to keep your reservoir full. The diameter of the tube isn't important. Select a size you are comfortable using with your hose. Rest your PVC on the bottom of the box (box not platform) and measure about 2" above the edge of the box. Cut it to that height.

Almost done with set-up! It took me two hours to get to this point believe it or not. This was because I didn't realize the drill had two speeds. I had to wait for the hubby to get home to reach the PVC scraps for me and then I had to wait for the dumb drill battery to recharge for an hour!

There will be a lot of weight on this platform. I deviated from the Tomatofest instructions again here by giving the platform legs. I used scrap 2x2 because that's what was laying around. They will likely only last a season because they will be in water all summer. That's OK, they are free. I cut the legs to the height of the top of the basket and then screwed them to the platform with a drywall screw. One in each corner and then two in the middle of the sides. The basket rests on the bottom and holds up the center of the platform. Before attaching the legs I cut drainage holes with a pretty big drill bit all over the bottom. The drill bit was about the diameter of my pinkie. Don't worry, soil won't fall thru these holes. We take care of that in a moment.

The hard part is done! Next is the overflow hole in the side of the tub. This hole assures you don't overfill the container or waterlog it after rainstorms. There should be an air space between the bottom of the platform and the top of the water. Put the platform in the container, measure about one inch below the platform height, and drill a drainage hole about the diameter of your pinkie. Use the same drill bit to drill a bunch of holes in the bottom of the PVC pipe. Make sure all the holes are lower than the level of the platform. These holes allow water to flow into your reservoir. Finally, take somewire or plastic ties and secure the basket under the 2x2 hole by wiring it to a couple of the drainage holes..

The next step takes care of the gaps at the edge of the platform. Cut a piece of landscaping fabric long enough to cover the bottom and both ends of the container, and overlap it about four inches over each end of the container. Cut a square hole in the fabric where the hole for the basket is.
Now move the container to where it's final place will be. It will be more than 150 pounds when full and you won't want to move it again. Now fill the reservoir with water until water comes out of the overflow hole.

Next pack potting mix (NOT POTTING SOIL! and not moisture retention potting soil) into the basket. Pack it well, it's important for proper wicking. Once soil mounds on top of the fabric covering the platform, spread about two inches of potting mix and soak it completely. Then put down another two inches and soak it. Repeat until the the soil comes right to the edge. Sprinkle a balanced organic fertilizer around the top edges of your soil and if indicated, add dolomite lime.

Now it's your choice, you can either place a plastic garbage bag over the top and cuts slits in it to plant your plants or you can plant your plants and lay a couple of garbage bags down on either side of them. Once the bags are down, lower the the lid to secure the garbage bags at the edges. The Tomatofest site has awesome directions for making a tomato cage (which you need to make before your fill the container.) I didn't got that route. I put my container against the house and will be building a cage around the container.

Sorry about the blurry last picture. I was in a rush to finish because the family wanted to take me to see Earth. Tomorrow I will go out and trim up the plastic, straighten out Carbon and remove the green poles which I won't be using.

This was a super easy, project and knowing that I saved roughly $40 made it that much sweeter.


Bucolic Bushwick said...

37 gallons! Wow, that is big. How much water does the reservoir hold? Great job, please keep us updated on how the tomato plants do.

Tatyana said...

Good for you! I am curious if it'll give nice results. Good luck! I bought the original Earthbox several years ago and didn't have good tomatoes, so I never used it again. Keep us posted, please.

Stacy said...

Bucolic, It's a lot. I'm too lazy to break out the tape measure and do the math but I'm guessing about ten gallons. Plenty to allow me to take a week vacation during the hottest part of summer I hope!

Thanks Tatyana, I'm hoping it goes well. There are entire forums dedicated to the homemade ones now and their results are pretty amazing. Fingers crossed!