Aquarius Farms - Structural Modification of Tomato Starts to Maximize Production in Cold Climates

Adam Klaus wrote:Interesting stuff, well done experimenting.
Thanks! Our entire operation is an experiment at this point - we expect that to decline over time as we document and learn things such as the above.


What is the age for moving the initial seedlings into the second stage transplant container?
Its not so much dependent on age as when it achieves enough length to bury in a 6" deep soil cup with 3-4" of plant above it - typically this is around 4-6 weeks from germination depending on the tomato variety.


And what is the age from seeding for transplanting into the field?
Also dependent on variety as articulated above but our seedlings generally spend another 4-6 weeks in the greenhouse after transplant so depending on variety anywhere from 8-12 weeks, though 10 weeks seems to be about the mean.


When do you transplant to the field in relation to frost-free date?
We completely ignore it. Montana is so full of micro-climates that the "frost free" date for a zip code could be off by as many as 2-3 weeks. In addition most forecasting, including frost free dates, are based on models and historical data that largely do not address the impacts of climate change. Our temperature is regularly 3-5 degrees warmer than the "forecast" and our frost date 2 weeks earlier as we are on a SW exposure on a slope. Our last frost last year was May 12th - this year it has likely already passed back in the 3rd week in April but the "forecast" date is May 20th. We will be putting our Tomato starts in the ground starting Wednesday of next week - basically 10 days prior to the forecast "last frost". It pays to remember most forecasting models are built around historical data and assumptions that are largely invalidated by global warming. Our growing season is over 140 days and is extending by a week to ten days every season.

Sorry for the dissertation. Its a long winded way of saying we plant based on what the climate is doing and where it is going and not where an outdated model tells us it should be had we stopped driving cars 30 years ago...

Thanks for sharing!

Adam Klaus wrote:Thanks Thomas-

Where do you get the 6" deep soil cups?
I find your system quite interesting and am considering implementing it into my tomato scene.

-- We make them with newspaper and a caulking bottle - once you have it down you can make one cup every 2-3 seconds. If you like we can post a video of how to do this on our Youtube channel. Should be able to get something up this weekend - like our FB page facebook.com/aquariusfarms or goo to youtube.com/TheAquariusFarm for the video once posted.

I asked about planting dates more from the standpoint of planning when you start your seeds. Sure there is a lot of variation. My historial date is around May 15. I have seen last frosts anywhere from April 15 to June 5. This high level of variability is a challenge, but I still have to make an educated guess back in March when to start my plants.

Doing it our way we just start March 1. The large soil cups leave plenty of room for continued development without getting root bound and results in a more mature plant that goes into production sooner. As we can fit 288 seedlings per 1020 tray (another benefit of this method) we can cram 30,000 starts in a 10x12 start room March 1 and avoid having to deal with heating our GH until April as they are inside under lights during this time. Once they go into soil cups they have a 6" stem to develop into roots so we have much more flexibility in transplant dates without becoming root bound or stressing the plants.

I generally start seeds around April 1. Then transplant as early as May 15 if the weather looks really benign, or as late as June 10 if unsettled. Frost date aside, I feel like soil temp, which is more consistent year-to-year, is a huge factor at transplant time. So even if the weather isnt freezing, I play it conservative and let the soil warm thoroughly.

I am really glad you brought this up - I am working on an informational packet about hugelbeds that addresses the soil temp issue. Because of our SW exposure and the "heat sink" effect you get from manipulating surface area to cold earth contact with a Hugelbed our soil temps are higher than needed for proper plant growth a couple of weeks BEFORE the last frost. This is because a hugel built tall with a narrow base has a dramatically increased surface area to absorb the suns heat and a substantially smaller contact area available to pull that heat out into the earth. Heat loss to the air is trivial by comparison as it is thermally much less conductive than the soil. Basically the Germans invented this method of agriculture to provide increased soil temperatures much earlier in the season to allow more effective use of a short growing season. It provides no absolute benefit in season "extension" (cant move frost dates by piling up a bit of dirt), but rather allows the farmer to make much more effective use of existing season through elevated soil temperatures.


The woody material and organic stuff has nothing to do with "composting" in the center of the bed - it is simply a practical solution to a HUGE problem if you dont have access to heavy machinery. When you fold a surface and create say 4x more surface area you end up with 1/4 as much top soil per sq. ft. It has to come from somewhere so either you haul it in from elsewhere (umm maybe with horses, if you are lucky) or you drop the organic stuff in place as you clear the land, pile the branches on top, and wait for it to decompose. Arguments about water holding capacity aside the "composting" in the center of a hugel while it is "maturing" is a huge PROBLEM, not a benefit, as it causes substantial nitrogen lockup until the material is sufficiently decomposed that excess N is made available for the plants. When building hugels use material that is as pre-decomposed as possible to avoid a need to heavily supplement with N for as long as a decade or more if fresh and hard to decomp material was used in construction.

A hugel can be made from anything - just depends on what you want to grow with it - how it is shaped is primarily a function of the soil temperatures you are trying to reach. It is a basic ratio of surface area to cold earth contact, the higher the ratio the higher the soil temps. A low flat hugel will basically do nothing for you in this climate aside from a minor increase in surface area available for plant growth - you need to make them large with a narrow base and your tomatoes will explode the minute they touch the soil. We have soil temps above 75 degrees in our hugels for the past two weeks.

Another thing we have found that goes against the "common wisdom" with hugels but makes total sense from an empirical/scientific standpoint is that we actually need TONS of water with hugels. I am not equipped to have arguments on relative efficiency of use but I can tell you that when you fold a surface so you are putting 8 acres of produce in 1.5 acres you get the following effects based on the physics.

1. More plants, plants are 80% water, more water is needed
2. More plants, evapotranspiration increases, more water is needed
3. More surface area, evaporation increases, more water is needed
4. Inclined surface area, runoff increases, more water is needed
5. Increased soil temperatures, rate of evaporation increases, more water is needed

Our own rough calculations indicate that even if our hugels were made from PURE WATER we would still require irrigation - the physics in this case invalidate the "common wisdom" RE hugels and irrigation. Differences in construction methods can make a minor difference but are an order of magnitude smaller in their impact than the above. Of course please caveat our experience with the understanding that we are a commercial vegetable farm and our experiences are driven around the needs of feeding a LARGE number of people - use of hugels in a "backyard" garden may not clearly illustrate additional water needs. We have consistently measured a dramatically increased rate of water consumption in our hugels vs. flat ground right next to it based on soil moisture readings throughout the season - this again confirms what the physics tells us - more surface area + higher soil temps + more plants = more water. I have attached a couple of rough drawings I use to illustrate the heat battery concept of hugels - if soil temps are holding you back from earlier planting dates this is probably the answer - just be prepared to irrigate like a crazy person with all the increased surface area.


thanks again, glad to have the discussion
Adam