Earth-Box Aeration Screen - - I Don't get its Real Purpose

[feralcatfriend]

Ray,

Thanks for the clarification about using an inverted box (so there WILL be a gap) and the great photos! One caution--when you use packing peanuts to fill the gap, make sure they are styrofoam and not the biodegradable kind.

I have the same kind of cages you do and was considering making stronger ones this year of concrete reinforcing mesh. My tomatoes crush the cages and break down the bamboo stakes I've been using once they get a decent number of full-size tomatoes on them, so I am looking for a better system of caging and staking when I switch over to self-watering containers. Our mid-Atlantic summer thunderstorms can get strong winds, so I have to consider that, as well. I don't think the guy wires would work for me--even with the outriggers, which would be barriers in the aisles between my plants. A senior citizen neighbor loves to help me water my tomatoes and guy wires would be a nearly invisible trip-and-fall hazard. I have my doubts about creating plywood platforms, too, for my situation. They would be very expensive for the number of containers I'm planning, plus, the container plastic is not so rigid that it couldn't pull away from screws, even ones with a big flange under them. I'm not saying it's not a great idea--I think it would be perfect for containers on a deck or patio. Ditto for the guy wires.

My concerns about making my own concrete reinforming mesh cages are the cost and work I'd have to do, plus whether I could make them foldable so they'd be easy to store. However, yesterday I was in the fencing section of Home Depot and saw some eight-foot tall 2x2 (or thereabouts) posts for around $1.50 each (about what I was paying HD for bamboo stakes!). I think I would feel safer about my tomatoes staying up in a strong wind if I had one on each side of the cage in a self-watering container. They would be strong enough to keep the cages I already own from getting crushed and would keep the containers from falling over. The downside is the amount of time it would take to pound in about 256 of them (4 stakes x 64 containers) at the beginning of the season and then pulling them out at the end. My strategy for that will be to wait until right after a nice, long soaking rain when the ground will be soft. I think I'll use my old bamboo stakes inside the containers to support the sides of the cages and individual stalks.

I'm enjoying everything everyone is sharing about their caging and staking systems--it's a big help in figuring out what's right for my own growing situation and budget.

Cynthia

[rnewste]

Cynthia,

I now understand your ground situation. The 2x2 staking is going to be MUCH better than bamboo stakes. In fact, you may only need 2 per container. Since your containers are on the ground, you have the option of driving those stakes deep into the soil. Most of my Earth-Tainers will be sitting on my redwood deck, so I didn't have the option of driving stakes into the ground. Also, our weather in San Jose is rather benign during our growing season - no rain, thunderstorms, or windstorms from May until October.

Regarding your thought of making stronger cages out of the reinforcing wire, I would advise against it. These things are really dangerous to make (people get cut, stabbed by the ends when they are bending them, etc.). Instead, consider taking 2 of the existing cages you have, and simply slip one inside the other, shifted 45 degrees, so that you now have an 8 leg, "double strength" cage. No amount of tomatoes on the vines will collapse that thing - and storage of these cages will take far less space than the reinforcing wire ones.

Regarding watering, my next steps are to set up an automated watering system, so that I never have to fill the 'Tainers with a hose. I've ordered the 12 unit Automatic Watering System (AWS) from the good folks over at The Earthbox Company, and am now figuring out how to modify the "on/off" internal valve settings to then adapt to my 6" deep water reservoir. When I get this complete, you may want to consider doing something similar. With your 64 units, watering each one will take considerable time.

Here is the link to the AWS:

http://shop2.mailordercentral.com/EarthBox/prodinfo.asp?number=EB%2DWS%2D12+EB+KIT

Ray

[MsCowpea]

My own theory is that the original Earth-box inventor (who lives in rainy Florida) put holes in this surface to drain off excess rainwater back in to the water reservoir - - NOT to somehow deliver Oxygen to the root system.

I have been a fan of Earthboxes (real ones--I have eight) for many years. I have made a few homemade ones too.

I always tell people to splurge on at least one--you really get to know how they work and how to set them up. A lot of people going by the home-made sites don't get some of the basic principles.

The screen really isn't draining rainwater as you really will get very , very little to NO rainwater in the container if set up properly. It could pour rain for a week and my Earthboxes would be dry as a bone if I did not water them everyday.

You might get a tiny bit of rain water when you have very small plants but not very much. You must fill the earthbox so that it is mounded on top. The plastic mulch covers the whole top and drapes over the sides--so any rain water is shedding off the top not sitting on the plastic.

Water coming in from the top would be disasterous as you have 2 cups of fertilizer sitting there-- enough to burn the plant if it got overly wet and dissolved.

I used to have a scientific article written by the inventor
explaining the box but I could not find it. I did find a link explaining the patent a little bit but this is not as good as the article he wrote. (Check out paragraph 6.)

http://www.wipo.int/pctdb/en/wo.jsp?...4&DISPLAY=DESC

Good luck with your boxes.

EDIT I just looked more carefully at your pic with very few holes. I could be wrong but I think your soil will be waterlogged. You have a large 'wicking' basket constantly wicking water up into your mix--I think it will stay very wet--possibly too wet. To me it is as if you will have a big container with no drainage to speak of at all--remember the basket is constantly sitting in water. But experiments are always good--good luck.

[rnewste]

Ms. Cowpea,

Thanks very much for your comments and especially the link to the Patent. I am a big personal fan of Mr. Blake Whisenant and what The Earthbox Company is trying to do via U.N. and other initiatives to help "teach a person how to fish" in impoverished areas of the World, so that they can begin to grow their own food in Earthboxes to survive.

I just spent $160 at his Company to purchase their Automated Watering System, and will likely buy additional items from them in the future. Some weeks ago, I found one of their local dealers, and with the expectation of coming home with several Earthboxes at $60.00 each (I had no problem with the price), when I saw the Earthbox firsthand, I was deeply disappointed in how small the unit's capacity actually was.

I am only interested in growing tomatoes in this type of container system, and when I saw the actual internal dimensions and cubic area of potting mix capacity, I returned home empty handed. In growing Beefsteak tomatoes like Brandywine and other similar size varieties, I simply concluded the root ball would be constrained, and would not allow the tomato plants to reach their full capability.

So, I calculated that for the tomatoes that I want to cultivate, I needed a capacity of 15 gallons per tomato plant in overall design. Hence, I embarked on designing / modifying 31 gal. Rubbermaid container based Boxes, as none with this capacity are offered currently by The Earthbox Company.

I started this thread and its title because as an Engineer, I wanted to understand the "Science" of how each component of an Earthbox works. where I ran into a "brick wall" was in trying to comprehend the purpose of a honeycomb "Aeration Screen", as Josho and many others refer to it as. As is indicated in Para 6:

"This ensures that the top portion of the drain volume will be filled with air and that the growing medium housed above the permeable partition has contact with the air, such air being important for proper plant growth."

This is the "science" that I cannot comprehend. If this massive "contact with air" through the underside of the plant is necessary, then why do plants grow well in in-ground gardens, or in containers without this "aeration screen".

I have come to the personal conclusion that the honeycomb "aeration screen" is there more from a plastic injection molding (cost) and strength perspective - not to provide massive air quantities to the root system. Look at the common plastic milk or bread crates delivery companies use at food stores, and this commonly used "egg-crate" molding pattern provides low manufacturing cost, light weight, and structural rigidity.

So my view is that people who try to design their own Earthbox-like solution should NOT try to blindly replicate fabrication techniques used for a rigid injection molded commercial product like the Earthbox.

The "eco-system" of available materials to the home-builder is limited to commercial raw materials like the Rubermaid containers, and one must adapt their construction techniques to the physics of these materials. Replicating an "aeration screen" with dozens of drilled holes in a home built system is not a logical requirement, and it only weakens the "bench" unit itself, and allows Potting Mix to leak through all these unnecessary holes into the water reservoir. If someone has scientific evidence that counters my conclusion, I would gladly like to study it.

"Inquiring minds want to know"

Ray (a.k.a. "Mr. Spock")

[dice]

[re: holding them up in strong winds]

This item might be useful, too, if the containers are
sitting on earth (as opposed to a deck, concrete,
masonry, etc) and the containers have rigid construction:

http://www.pplmotorhomes.com/parts/r...ral-anchor.htm

If you use two per container, that would be an extra $5-6 each.
If you use two per row, maybe with something like a volleyball
net between them and over top of the containers, ...

Edit:
Net material should be nylon, or some uv-proof synthetic, etc.
Fabric may stretch when wet and eventually rot from weather
exposure (remembering watching a 40-lb Chinook salmon drop
through this guy's decrepit fish net back into the water once,
leaving the hooks behind in the net; he went out the next day
and bought a new nylon net).

[rnewste]

Thanks Dice,

Those anchors would be perfect for Earthbox-type ground based containers. I'll bet with the right tomato cage rigging, they could tolerate 60 mph wind gusts with no problem (the tomatoes would likely blow off before the container would tip over). Looks ideal for Cynthia's application.....

Ray

[dice]

I was wondering about some kind of spring-loaded, articulated
support, with a pivot at the bottom right above the container.
Then then the wind could blow the plant over if it gets that
strong without tipping over the container, and it would spring
back when the wind let up.

Kinda high-tech for tomatoes, though. Use a support that
fancy, and it is likely to walk off in the middle of the night.
Maybe something cheaper and merely flexible would be
better. Spring-steel cages?

[rnewste]

Let me get out my Slinky,,, and think about it.

When I get my EarthTainers all set up with water in the reservoir, and potting mix installed, I am going to take a strain gage and see how much force it will take to tip them over at the top of the tomato cages. During the course of the growing season, the additive weight of the tomatoes should just add more downward force, but the tomato plant itself will act more like a sail, so we'll see...

Ray

[MsCowpea]

Ray,

I can understand how you were disappointed with the size of the earthboxes. They used to be a bit bigger. Don't know why they made them smaller. I also like a 15 gallon container.

(link) I don't know if you want to plow thru some of the original EB patents. I believe Geraldson and Whisenant worked together.

This one is interesting because it shows a container within a container type set up but he particularly specifies that the inner container is perforated on the bottom and even the sides.

I also found an original Whisenant patent with multiple designs.

As to your original question--Plants in the ground aren't really sitting on top of a pool of water that is providing continuous moisture that has no way of draining away. If they were then the roots would be waterlogged and not be getting sufficient air and all the subsequent problems that result from this condition would develop.

I think any design will work as long as the soil does not stay too wet.

According to the EB people you really don't have to worry about the little bit of soil that escapes down into the water reservoir when you are packing it in the container. I noticed you said you would use 'peanuts'. My earthboxes have got gaps all around the screen-but if you moisten your mix it really doesn't fall through all that much.

And , no, I don't think you have to blindly copy the EB to a T. I also like to experiment and I am sure that there are always improvements to be made. You can see this when you look at all the multiple and varied designs that were patented by the inventors over several years.

http://www.google.com/patents?id=qUY...lake:whisenant

http://www.google.com/patents?q=blak...Search+Patents

[Mantis]

The mix in the tub will wick water from the resevoir. If the top tup struture has no ability to breath the roots will drown. Keep garden grown tomatoes flooded and you will kill them as well me thinks. Its not rocket science, like Earl said , worm aerated soil grows better plants.
Mantis

[rnewste]

Thanks for all your observations, links and suggestions, folks.

OK, I will double the number of drilled holes in the recessed areas of the "potting mix bench" so that any water that accumulates will flow freely back into the water reservoir, and not water-log the root system. This has been a very helpful discussion.

Ray

[MargeH]

I spent the morning at the Earth Box Research Center in Palmetto. Blake Whisenant gave a lecture-demo. When he held up the screen, he said that he had experimented with more holes and fewer holes. He said that the amount of holes they ended up with gave the biggest yield.

It was fun to see what they have growing in the boxes. They also sell seedlings; the tomato seedlings just said grape, plum, patio, etc., not specific names. It might be worth a field trip to anyone in that area. They give lectures on Wed. and Sat. mornings.

Blake started with an Earth Box that had been growing 6 cabbages. Two were still there and they were REALLY BIG cabbages. The box was set up with the fertilizer strip down the center the long way. He was changing the box out to tomatoes. After he had cut the cabbages off at the soil level, he added a thin layer of new potting mix to the top and in that he mixed dolomite. Then he dug a trench in the area where the fertilizer strip had been. This was the interesting part: near each end of the Earth Box in the center (where the trench was) he dug a hole deep enough for the tomato plant. He then filled up two styrofoam cups with potting mix and turned them over in the holes, leaving the cups in. He then cut the bottoms off of both of the cups and filled the trench and around the cups with fertilizer. Next he put the cover on the box, felt around until he found the position of the cups and cut holes in the cover. He then planted two small tomato plants inside the cups. He said the cups would protect the plants from the fertilizer and that the roots would grow down and then out. He said this way, you could use the box year-round down here with colder crops and then tomatoes.

He talked about TYLC virus and predicted that it wouldn't be long until all growers in the area were growing only resistant varieties, oh well. He did have seedlings of a couple of ones just released to the growers. I bought two of them because none of the TYLC resistant ones that I had planted germinated. People asked him how they tasted, he said he didn't know because they were new. He also mention that UF was releasing a new variety in March that had been bred for flavor.

____
Marjorie

[MsCowpea]

Marjorie, thanks for posting what you learned at the EB center.

I found that place strictly by accident as I was looking to visit the historical house that is right next door. Been back twice but have never been there on the days when Mr. W. has spoken though I have spoken to him on the phone. And he was extremely helpful. I will plan another visit when I know he will be there to teach the introduction just for the fun of it.

I have never got into reusing the soil--it seems to be nothing but roots. I dump it every time and start fresh.

I have some 'used' ones right now that I grew tomatoes--I had been thinking about planting some Seminole pumpkins in them. Now I will for sure.

[rnewste]

Marge,

Thanks for the information on holes in the aeration screen, from The Man himself!!

I have just finished my caging system for the 12 EarthTainers, and am now installing the automated watering system (had to "add" 3" of pipe extension to adjust for my 6" water basket). Just checked the water level out and it holds to a constant 5.5" depth, with half an inch air pocket below the aeration screen.

So before I begin filling the 'Tainers with the potting mix tomorrow, I am going to now drill double the number of holes (again).

Ray

[MargeH]

Blake was an interesting speaker. He said that he had some boxes with soil that was 12 years old - he was "cheap" and didn't believe in wasteing anything. The box from the cabbage was obviously full of roots. He used a saw to cut out the trench. He said the roots would rot and add more organic matter. He did say that in the summer he would solarize the boxes by covering them with clear plastic and leaving them in the sun.

I won a coffee mug because I was the only person in the audience who knew the answer to one of his questions. I credit this place for the things I have learned about tomatoes in the last year.

He talked about their farm and one field that is set up with 400 boxes. I'd love to see that in a couple of months. Someone asked him how he supported the tomatoes in the box. From what he said, it sounded like his favorite method was a form of the Florida weave. He didn't call it that, but his description sounded like it. He didn't like cages because he said that they crowded the plant and cut down on the amount of light they received.

One of the most unusual things they had growing in a box was a papaya tree. He said they also had grown key limes in them.

____
Marjorie