Rex Reeves wrote:Have you looked into Sepp Holzers method of growing citrus? Paul Wheaton has talked about it recently in one of his podcasts. I understand it has a solar reflector pond in front and a heat retaining berm behind. Might be right up your alley.
Another thought is a large high tunnel that can utilized during the cold nights and then left open the rest of the year. A RMH inside would do a lot more than one outside. I don't know about your location but where I live wind chill would be a huge factor in heat loss.
I'm not sure one RMH outside would be enough. You might need a series of them in a ring around the trees. I think having some data from an out door RMH and the temperature differences at various distances throughout a typical night would be great information.
One question I try to ask myself before starting a project is "do the gains justify the means?" Will the profit of selling the fruit or the benefit of having it grown on your property be worth the amount of work that goes into keeping the plants alive?
Best of luck on your adventure.
Dave de Basque wrote:
Hey Rex, thanks for chiming in! I really appreciate your input.
Yes, I'm a big fan of Sepp's. In the design I'm working on, there is a substantial slope going down to the west (WxSW), so a reflecting pond to the south is not going to work. Citrus trees would be in a northish-southish line up against a WxSW-facing gabion wall, and behind the wall may be a rocket forge among other things, so between the west and slightly south orientation and what's behind I'm hoping the rocks will provide some warmth.
The high tunnel structure is a great idea. I could leave a hoop structure set up (maybe a half-hoop given the gabion wall on the uphill side) and cover it as needed. I've wanted some kind of tenting strategy but if there is some way to kind of accordion-fold the high-tunnel cover that might be great. Does anyone know of a video showing some sort of an idea for something like a retractable high tunnel cover? Or any other kind of retractable cover outdoors for trees?
You're right that it would be nice to have data about temperatures at various distances from an outside RMH. The effect of the "smudge pots" with oil in them used in citrus orchards of my youth must have been substantial, even though they were dotted around pretty sparsely, because people actually used them and it can't be cheap to light a pot of oil on fire. If memory serves me correctly, maybe there was one smudge pot every 5 or so trees in a row, maybe every 10, I don't remember too well as I was a kid. I think an RMH bench running by each tree would have to work way better.
I'm thinking of a long series of RMH benches covering about 40 meters (130' or so). This would go between a line of the most sensitive trees like, say, lemons, which would be against the gabion wall, and the second line of less sensitive trees (satsumas or whatever). And have some system rigged up to cover the whole deal when freezing temps threaten.
There are big greenhouses already in this design, and I don't want the place to become a plastic jungle. That's just my hesitancy to having the trees under permanent cover, there will be other more tropical trees under permanent cover in the greenhouses. I basically need to provide potentially +7°C (12-13°F) temperature support maybe 30 nights a year.
The "justification" for all of this is basically self-sufficiency. For one, resiliency, so if supply chains deteriorate at some point people still have what they need locally, and second, because there are some things that are marginal or impossible to grow locally, that realistically no one is going to give up: lemons, bananas, mangoes, pineapples... Maybe people would cut back, but I for one am not going to say I'll never have a pineapple again because I don't live in the tropics. So rather than setting myself up to import these things over tens of thousands of kilometers for the rest of my life and exploit the whole third world export agriculture chain, it seems reasonable to develop a really eco-smart way to grow what people are actually going to consume, locally. Which is what this is all about.
Don't want to create an ethical firestorm about this. Part of the reason I'm inclined to go for it is that my area does not have a severe climate, but there are a few freezing nights every year. Providing some support over those few freezing nights, you really open up the window of what it's possible to grow locally.
William Bronson wrote: I went and read about how the old pots worked and what has been replacing them.
I want to see if the smoke was considered a bug or a feature.
I was concerned that it was contributing to the heat transfer/ distribution.
Seeing as the smudge pots are being replaced with "clean burning" propane, it seems that the smoke isn't important.
You could build individual rockets with bells for long term radiant heat, or you could build a single rocket powered "boiler", heat up a mass of water and run water lines wherever.
If you are already gonna have a greenhouse, you could have a water tank as a thermal mass, solar and/or rocket heated and run loops to barrels where you want radiant heat.
That being said, individual solar tank collectors could serve individual trees or zones.
So I left, I came home, and I ate some pie. And then I read this tiny ad:
Sepp Holzer's 3-in-1 Permaculture documentaries (Farming, Terraces, and Aquaculture) streaming videohttps://permies.com/wiki/141614/videos/Sepp-Holzer-Permaculture-documentaries-Farming