Earthtainer Greenhouse????

[dfollett]

Thanks for the information. I have a lot to learn. I am going to use a soiless mix - starting with the blends Raybo recommends and trying different variations from there to figure what works best here.

Like I said, there's a lot to learn - It should be fun.

[JamesL]

It is an interesting problem. I have questions after thinking about it more.
What are you using for your media? Soilless media would be sterile, until you open the bag of course. Raybo's 3-2-1? Something else?
Aq Heaters - the more expensive ones are either thick borosilicate or titanium. Some come with sensors that shut off when dry. That would seem to be a required feature for an earthtainer application.
Plans for auto watering system?

If you go the heater route, how many earthtainers are you willing to commit the 1st year?
I would think that a temp setting of around 60 at night would probably do the trick. You only need to keep the 'tainers above 35 at night.

What varieties are you planning on growing?

All in all I think it would work.

[dfollett]

What media? - For media I am going to test two - Raybo's 3-2-1 with Sunshine Mix #4 and a mix using Lowe's Sta-Green Potting Mix in a 3-3-2 mix (I read a post from Raybo recommending that mix with the Sta-Green) - That mix is 43% less costly than the Sunshine mix.

Aq heaters? - Probably should have gone with the fancy ones, but I am already going to have the most expensive produce in the state. I bought some inexpensive 100w heaters. Unfortunately, I don't have an option of adjusting the temperatures as needed. They are hard-wired for 78 degrees. Even the expensive ones that are adjustable have the adjustment on the heater itself, which will be inaccessible once it is installed.

Auto Watering System? - Yes, I am planning on using an auto watering system. However, during the time I will be using the heaters, I won't be using the AWS because they fill lines would freeze at night. My logic is that I'll make sure the containers a full each morning. During this early part of the season they won't be pulling tremendous amounts of water. I will not use the heaters once we get past the first of June unless we have an extra cold night forecast.

# of Earthtainers? - I am going to commit two (possibly four). I will set out two in the next couple of weeks without plants, but with soil and water. I'll monitor the soil temp and air temp inside the wrapped cage through March and use what I learn to decide how early in May (or hopefully April) I am comfortable setting out planted ones.

What varieties? - I haven't decided for sure. I have never grown anything but early season tomatoes and then get mostly green ones. I am trying to start my own and have a bunch of different varieties. Right now, I am leaning toward an early season variety (Early Girl or something similar - for tomatoes in June or July) and a mid-season heirloom (Black Krim?) in each earthtainer. If I can extend the season, I'd like to get something besides early varieties.

Any recommendations on varieties that do well in the earthtainers would be welcome.

[rnewste]

Sta-Green potting MIX will work well. Just amend it with microbark and perlite. Don't use potting SOIL.

Raybo

[JamesL]

dfollett,
Watering plan- Makes sense to me.

Heaters - A 35-45 Thermo Cube might be worth a look as a $15 fail safe/temp controller.
http://www.thermocube.com/

Earthtainer and Varieties - I don't think you will find any limitation on what plants you can grow in the Earthtainer. As to varietal choice, Well, that's always seems to be the hard question! Short season, I guess you have to gauge it on what you can get to harvest.
There has to be a thread here somewhere on best short season varieties.

How about posting a pic of your setup once you get it up and running?

[rnewste]

Be sure to allocate an EarthTainer or two for cukes. They love them:



Raybo

[dfollett]

Thanks for the link to the Thermocube. I think I'll order one. That could come in handy.

I'm planning on two for Cukes (Great photo Raybo) - two for Peppers - four for corn (I have only had one decent crop of corn in nearly a dozen tries). I'm thinking about trying one or two for squash - the rest for Tomatoes. Anybody had success growing squash in Earthtainers? Do you try to cage them and have them climb or let them sprawl?

I'll post photos of the Earthtainers once I get them set up and start testing. I'll also post some with plants if I can get something that looks even a fraction as good as those Raybo and some of the other folks post. If I can't get any that won't embarrass me, I'll probably declare failure and skulk off quietly until I get something that looks decent.

[dfollett]

I have some questions for Raybo and others who need stepladders to harvest (the more I learn on the front end, the better chance I have of generating something others can learn from on the back end):

With the short growing season I'm sure plants won't crowd as much as when you grow them for 9+ months - given that, how many cukes and peppers should I plant per Earthtainer?

With cukes and peppers, I assume you put a fertilizer strip down the middle?

How do you handle the fertilizer with corn? I believe you do 3 rows of 5 plants?

I'm finding it difficult to locate the micro-bark for the soil blend. I found a locally produced product at Lowes a "Soil Prep Conditioner" @ $4 for a 2 cu ft bag. It is "80% composted micro-bark and 20% composted steer manure" according to the manufacturer. Do you see a problem using that as the bark component? I understand this is not an exact science and there is a lot of latitude for different products to work. This is a photograph of that product. Would you continue looking for pure bark or not worry about the 20% manure?

Thanks in advance for your help.

[rnewste]

For your Grow Media ratio, since you are using Sta-Green and the bark with composted manure, I would increase the perlite ratio to a 3:2:2 composition..

Fertilizer strip - across the narrow dimension centered for tomatoes amd peppers. 2 tomato plants per EarthTainer, same for peppers. Cukes - fertilizer strip centered in the long dimension. Plant 4 plants each evenly spaced along both outer edges of the 'Tainer. Corn - mix 3 cups fert deep in the Grow Media (no strip) plant 3 rows of 5 stalks each row.

Raybo

[dfollett]

I got one ready and outside today. I'll post photos and short explanations:

1 - I attached the aquarium heater to the side of the insert.
2 - Attached with Zip ties
3 - Zip tied the cord to the outside of the Earthtainer where it exits so if I catch and pull the cord it will not damage its connection to the heater.
4 - Filled the Earthtainer with soil (everything as if I was going to plant except the fertilizer strip) and covered it with clear plastic (clear plastic heats the soil more than black plastic). When it gets hot in the summer, I will cover with bark mulch to keep cool. Right now I want warmth to the soil. I also used the darker containers for warmth.

I set this one on a 2" piece of insulation on a mover's dolly. I want to be able to move it easily and I don't want the cold ground to suck the heat out of the 'Tainer. It's costing me to heat it, no sense in heating the ground beneath. I set two thicknesses of paper to shade the temperature monitor so I'll get a true air temperature inside the cage without the sun shining on the monitor. A waterproof temperature probe is inserted about 4" into the soil where a plant would be. This probe transmits both temperatures to an access point attached to my internet. Thanks to whoever recommended this monitor (it was on this site somewhere). It seems to work well and is easy to set up.

5 - Installed the cage as per Raybo's instructions (dang clever, Raybo)
6 - Wrapped it with stretch wrap
7 - Built a lid out of 1/2" PVC wrapped with stretch wrap. I used tees pointed down in the middle of all four sides to keep it from sliding either direction and use bungees on the ends to hold it down.
8 - End view with the cover in place
9 - I only included this picture to show the snow in the valley below, the mountains across the valley and to show off the view I have to put up with. I have another temperature monitor on the shady side of the post along side the 'Tainer to monitor actual outside temperatures. It transmits just like the one inside the cage.

When I finished, it was 51 degrees outside. I put the lid on and it quickly warmed to 85 inside. I removed the lid and it settled in the low 70's. It's currently 52 outside and 70.2 inside the cage. The real test will be early mornings and how well it holds through the night. The stretch wrap certainly won't insulate, but my hope is the soil and warm water will radiate enough heat to make a real difference in the cage above the soil.

I will build another Monday without a heater to run for comparison. I'll build a third Wednesday with a heater and plug that heater into the 35-45 outlet JamesL recommended above for another comparison. My fear with that is that it won't respond quickly enough. I think the heat needs to already be in the soil when it gets cold.

Today is the first 'warm' day we've had in a long while - another snow storm tomorrow. The forecast for the next week has three days of snow, highs between 32 and 42 and lows from 12 (tomorrow) to 22 (21 tonight). We'll give it a real test.

It'll be fun.

[rnewste]

Nice construction quality!

Curious - were you not able to find the Centrex brand containers at Lowes? My experience is that the Rubbermaid brand will crack after about 4 year's use. The Lowes Centrex are lifetime. Anyway, you can wrap them in bamboo or rattan material to extend uV protection.

Raybo

[dfollett]

It was unintentional. I built a couple of Inntainers first. When I decided to build the larger Earthtainers, I skimmed the instructions and saw the size. The dimensions of the 31 gallon Rugged Totes at Lowes and the 31 gallon Rubbermaid Roughneck totes are identical. I had all the totes bought and most of the building done before I noticed that it was different. I justify it to myself by saying I like the darker color for warmth, but the reality is I didn't read close enough. I did build three using the Lowes tan ones. I'm going to give them to my kids - it is quite a bit warmer where they live.

Live and learn......

[rwsacto]

Very interesting design details. Thank you.

I also tried some early spring heated earthtainers a few years ago. A 50 watt aquarium heater worked fine and only used a kWh per day. I also set the container on a piece of insulation on a moving dolly and moved it in and out a lot in early spring. I used part of a water heater blanket to wrap and insulate the container.

I also used a seed germanation mat under an earthtainer for heating. It also worked fine. Soil temps stayed in the 70's.

In the summer, you can make a mulch cover with a split white trash compactor bag. It is heavy duty and will drape over the sides to shield from the sun.

Another suggestion is to investigate an automatic vent opener for the top of your greenhouse. Less expensive ones are available from that freight store near the harbor (but are not 100% reliable). I have used them successfully on cold frames.

Good luck
Rick

[JamesL]

Nicely done! With that sun exposure, I really think this is going to work out for you.
Quote - the view I have to put up with - Yes, that view is truly awful. How can you stand it?
Quote - I skimmed the instructions - Tsk, tsk....
And one more I just noticed from Raybo,
Quote - after all how many tomatoes can one eat - Raybo how could you? Blasphemy!

Thermocube - Quote - My fear with that is that it won't respond quickly enough. I think the heat needs to already be in the soil when it gets cold.
You might be right. A plug in timer could be better suited if you are only planning on running the heater at night. Maybe set it to kick on in the evening and shut off when the sun is first hitting. Based on your initial temp readings, it would appear overheating might be a greater concern than under heating.
I used these $15 GE 2 plug timers for my Inntainers, but they would need to be protected from the weather in an outside application.
http://www.homedepot.com/h_d1/N-5yc1...1#.USJKZfI8B8E

Stretch Wrap - You are right, it is not going to insulate, but it appears to be providing a very nice "air seal".

Composted steer manure - I would be a little wary about going "all in" with it without a test drive. Would hate to fill that many Earthtainers and then have a media problem. I had the same issue in locating pine bark last January in that it was completely unavailable. Got a lot of strange looks at garden centers as to why I needed it "right now".
You will probably find it coming back in stock as we get into spring.
Since it wasn't available, I used Orchid Bark, in 2 Inntainers and Hydroton (Leca clay) in 2 others as the pine bark replacement for the project. Both worked admirably, but neither is a low cost solution.

Cheers, and let us know how it goes with the temp trials.

[dfollett]

I added one tweak to the wrapping around the caging - I wrapped it in bubble-wrap in addition to the stretch wrap. There is NO insulation with only stretch wrap. For the one I had already stretch-wrapped, I put the bubble-wrap outside. The second one I wrapped in bubble-wrap first (solid side inside and bubbles outside) then wrapped that with the stretch wrap. It was easier to install that way and seems to be more consistent.

With nine days of history since they stabilized, the average temperature differential between the inside and outside temps is 6.3 degrees (the range is 5.5-7.1). Without the lid, the differential is about 3 degrees.

That 6 degrees should allow me to set out at least a month ahead of the last frost date and do nothing more than wrap the cage like these (using the heater). I found the daily high and low temperature readings from a weather service station about 3 miles from here and got the daily readings since 1916. There are only 5 May days where the record low since 1999 (It is warming!) is below 26.

I'll spend the next few weeks playing with additional covers - wrap with moving blanket - plastic - etc - to see how much additional cushion I can get for those inevitable record cold nights. I'm shooting for an April 15 set-out date. I wanted to do April 1, but after analyzing the temperature data, unless I come up with something in addition to this, things are just too cold here in early April. Around April 10-15, the averages change significantly.

When things warm up a little, I'm going to also turn the heater off on one to see how much difference it makes. I haven't done that yet, as it is still quite cold. The low last night was 7.1 degrees.

We'll see!