Johannes Schwarz

Thanks everyone for the input and the caution about the light. That is a fair point. I was a bit naive, I guess - or "optimistic". The reverse-pyramid idea might be a solution.
I'll have to finish some projects first and then see what I could give a try in my location and will update when I'm there.

Ok. I have a Walipini style greenhouse (probably better termed: passive solar greenhouse away from the equator). It's been through its first winter in the Alps. It never froze inside. It bore the heavy snow on the north side and its solawrap shed it well on the south side. Citrus, Pomegranate, Feioja, Figs... all doing well. The young grape growing from a cutting did not even realize it was winter and never shed its leaves. Tomatoes suffered a little. Chilies are alive. I was happy. As were the mice :-/
It only has one flaw: it is of course too small.

I while back I saw this video:
Now, while a completely different climate I was wondering.... I have no room for bananas in the greenhouse.....

Has anyone in a temperate climate dug a hole supported by dry stone walls like an old well and planted, say at a level 5 feet underground in a hole with say 6 foot diameter? The advantages that I maybe naively have in mind:
+ in the cold season the rhizome is way underground and well protected from cold. AS LONG as I can avoid the hole becoming a cold sink. The hole would have to be protected with a mini greenhouse on top, which is then removed in the warm season. It would be like a mini walipini.
+ The bananas in the hole would have no height limit in summer as they would in the walipini
+ the ground in which the bananas grow would remain moist because the sun does not reach the bottom.

Note:
I'm on a slope and have no issue with water draining. The hole would never become a pool
I assume the banana (like in a jungle) will strive for the light and be fine with shade at the bottom (and cooler soil temps?)

Please let me know:
Am I in lala land or behind the times because everybody is already doing this in a temperate climate for subtropical plants?

Cheers


p.s. here is a winter shot of the my greenhouse just if someone was interested:

Well, Marie, I put them in the ground and we'll see what happens

Not Gen Z or Millenial, but at 37 I found myself buying a mountain hut in the Italian Alps with a plot of land 5 years ago. My steep slopes between rock walls and towers covered with chestnuts are not prime farming country (bought it for the solitude and the view - some 3000ft above the plain), but I have built terraces and am trying to grow a little food forest. In the olden days people cultivated buckweed and other things on such terraces (most of which have been reclaimed by the forest in the decades of abandonment)
For me it had started out as a crazy thought, some online dreaming (via immobiliare.it) and before long things got serious and I ended up in this corner because properties were cheap, I love the mountains here (knew them from previous hiking holidays) and if you were willing to put some money and work into a very basic building you had the chance to become a home and land owner for about 20.000 € ( I would have spent that same amount for renting a hut in my native Austria for 3 years).
For those looking at Italy and the cheap side. If you can, buy from the seller directly and do not go through an agency (which asks about 5000 € just in fees), but there are of course some things to consider before jumping into it (Italy is norotiously burocratic). I know other people who bought a very nice house with a new stone slab roof near me for cheap (40.000€) and with much more land than my 1.5 acres. They however found themselves needing to repair the new roof because of water damage (some badly done work previously to their buying). So beware of some hidden things that come up (and make sure the contract is tight and the seller can actually sell it) I was fortunate in all these regards, but building codes and rules regarding old houses have somewhat dampened my desire to build, construct and add on. That said, I have no regrets and will now use the evening light to see how my Amelanchiers are doing :-)

Italy btw has seen one of the largest returns of young people to the land (and often agrarian life style) in Europe (according to a documentary) even in the years prior to Covid. Their grandparents left for the cities and for work. And they are now returning (often with worthless degrees and little perspectives in the city), creating small businesses conected with the land. Now with Corona many more people are leaving the city. My closest small town of 4500 people has had an increase of 400 new arrivals from the Turin region over the last few months.

Hi,

I have 2 table grape vines that are mildew (oidium and peronospora) resistent (their musical Italian names are Francese Nero, Fragola Bianca Precoca). If they turn out to grow like an unknown vine I had in another location 10 years back, they will be unstoppable: no treatment, monsterous growth, full of grapes (only downside with that vine was: more seeds than the actual good stuff). I originally wanted to plant russian and moldovian varieties up here that are among the toughest but I could not get them here so far.
So anyway, these two varieties are given a trial up here in the mountains to see if they work in my climate (altitude + hoping the sun hours will be sufficient as I get cloud cover often in the summer in the afternoon). Verdict is still out. This is only their first season. I will report on the success or failure.

Now I was given two more - non-resistent - grape vines (Apirena Ametista [grown in the area but at lower elevations], Resistente Bianca [which however is not resistent according to the description]. These are still in pots because...
My question is: should I even plant them? I know that mildew spores exist in the garden as mildew has shown up on cucumbers (late in the season) and on Rudbeckias. The cucumbers produced well without treatment (removed a leaf here and there for good measure). The Rudbeckias don't care and grow like weeds throughout the garden. I'm sometimes gone for a month or two or three during the season  so I won't be able to treat the vines (even with biological things such as milk. ... And, yes, my budding food forest is mostly for the birds in some years... :-/
Three options:
a) I just put them in the garden and see what happens. Worst case: they don't make it, but I can have an eye on them when I'm here.
b) I throw them away because I would in effect just be growing mildew spors if I don't treat them. Worst case: more spors mean more problems for my cucumbers and other plants.
c) I go to some remote part of my property (up the mountain side in my case - I get no winds from there) plant them there and see what happens. There are no other gardens there, just old stone terraces, forest trees that are not affected by mildew. Worst case: they don't make it. But neither sun exposure (for the tall trees) nor alitude would be favorable there. So while this option would make it "safer" for the rest of the garden it would make it tougher on the grape vines that might already be hard at their limit where my garden is.
d) I have a small greehouse (automated watering) and could put one vine in a corner there. I would have to keep it tame to some degree but could protect it from getting wet leaves. That might take care of peronospora but I don't know if that would just make it more prone to oidium?

What would you guys do?

@Ellendra
that must look cool. I wonder though at which point a heating cable becomes more efficient. There are 30ft long cables consuming 100W which would equal to a single 100W bulb. Seems a more efficient way with lower running costs (though an investment) if the goal is not light but just heat.

@Eric
that seems like a good idea. It would basically be like my black water barrel in the green house on steroids. I use its thermal mass in a similar way

@Skandi
Yes, torches is what they use in many regions that I know too. But while it looks cool it works less on a steep slope with wind.
I've heard of helicopters and wind mills to stir up the air in a cold sink. But again, that method is more for folks in the valley (and naturally only viable for big commercial orchards). For the price of an hour of a helicopter I might as well install radiators near those trees pay a larger electricity bill.  

Late frosts can be real bummer. They ARE a real bummer. They were an absolutely real bummer last night in my garden. :-(
So I'm bummed.


My particular Problem:
My place is beautiful and up in the mountains. I'm at 4000ft, south-sout-eastern slope @ 30° incline (66%, so pretty steep). It is certainly not prime garden territory but I do what I can and select the plants that work for my zone - which is 7 (I have years that stay well within 8 and true laurel - zone 8 - grows big both against stone walls and free standing in the garden (for 20 years or more now). In fact overall temps are pretty benign in my micro climate during winter, but there is one thing that is bound to ruin things: late frost. It is worsened by the fact that at my incline the ground stands at a better angle even towards the winter sun and thus heats up quicker. On the slope there is no cold sink and I'm usually snow free after a few sunny days. I might have weeks on end of pure sunshine and above freezing temps in February and March. So things just start sprouting and growing. April and sometimes even May weather may turn for a few days. Cold air sent by the Russians hits Europe and the Alps. Last night it hit 24 F

Here is an image of the house and property (in May), though the garden below the house is not very visible in that pic:




Late Frost - Solutions for fruit bearing trees and bushes?
There are some solutions I'm aware of:
- making it rain on the plants as long as the temps are below freezing to use the heat that is generated in the process of freezing - sounds strange but that is physics and done on big plantations where there is such a risk (not feasable in my case)
- heating with torches (not feasable - also because heat travels up the hill and does not stay near the trees)
- putting garden fleece out there (works form some smaller things but not for big things)
- people (agrarean scientists - mostly in vinyards) have experimented with spraying a 10% vegetable oil solution in spring before the buds form which appears to delay things anywhere from 2-40 days depending on the weather and other factors in the case of wine. (can be a problem for plants that need the longest possible growing season - including wine that might need those sun hours to produce sugar - but it may work for other things. Research is still being done.)  

Other Ideas?
Has anyone experimented with other methods to delay leafs/blooming?
- There is the advice sometimes given to put early flowering plants that are at rist, like apricots, on the north side where it stays cooler longer. That can work for some. My land however is entirely on the southern slope.
- terracing. Terraces improve not only water retention but their level surface also decreases the angle to the winter/spring sun, thus the ground does not warm up as quickly. Snow stays visibly longer which proofs the point. One point with stone terracing though - as in my case - the stone wall retains heat which is great in cool summer nights and it protects from cool winds but that of course counters the desired delay of the ground warming up in the spring as well.
- mulching? Can mulch in a certain thickness isolate not only the ground against freezing but also from warming up too much? Anyone have experience with that?
- shading? When I look at the northern slope that I face it naturally stays cooler much longer. Snow covers the ground there when I pick the first flowers.. Since I can only plant on the south side, would it maybe be an option to construct artificial removable shade (from willow branches - woven like a willow basket - or with poles and fleece for example) and place that like a "wall" in front of the sensitive trees. It would place them artificially for a month or two onto "the north side" (of the wall) and prevent the ground from warming up - and thus delay blooming.

Hi Anne,

thanks for the reply! Yes, it is a nice place: .

Wood chips are hard to come by up here. I'm trying to find out if anyone in the area has a wood chipper that I could borrow. Otherwise I would have to invest into a solid machine and that would be rather costly. The garden shredders I have seen seem a little weak.
So far I use mainly maple and other "good" leaves to mulch. They accumulate on a small path up the mountain that I maintain. I could put a foot of that material under the trees as well to stunt the growth of the grass around them.

I guess my fear is that if I terraced the area under the tree to make it somewhat level with the stem that the roots that were formerly near the surface would then be burried and maybe find it more difficult. Or would they be fine and maybe develop upwards into the earth and mulch permed by the stone wall?

Hi forest gardeneers,

I live in the Italian Alps and have terrain that is south-southeast facing with a relatively steep grade: 30° = 55-60% (so roughly: for every 2ft horizontal the terrain rises a little over 1 ft vertically).

When I bought the place there were some established fruit trees such as apples, peaches, plums. All of them of shorter growth or pruned. The tallest ist about 12ft. Chestnuts grow in the forest around me.

Over the last few years I have built terrasses with rocks (some rock walls are 5 feet tall due to the steepness of the terrain). This was done to improve water retention, accumulate better and deeper soil for most of the slope otherwise has not much more than a foot of soil on sheer rock. These terrasses are also in keeping with the traditional type of mountain agriculture in the area which is a plus.

Learning more about forest gardening, I would like to shift to cultivate more perennials and seeing the incredible root system of the tough grass that grows on my mountain, I would like to make life easier for my trees, get rid of the grass, add some benefitial plants. Mulching can be done in principle but the only practical way to do this really is by terracing (otherwise heavy rains would just wash away the mulch downhill. With a radius of 6ft from stem to drip line, this would mean that the lower, southfacing, terrace wall would have to be about 3ft high to flatten the terrain. Where's the problem?  It's not the wall. I enjoy making them - including the huffing, puffing and sweat as I collect suitable large rocks from the surrounding mountains side (there is no other gym up here). But my worry is, that this the root system of the apple tree would then be burried under 3ft of soil. Considering apple tree roots are naturally shallow, would I be doing more harm then good? Does anyone have experience with earth works around established trees? Any recommendations?

Thanks,
Johannes  

Other details about the location - not pertinent to the question, but usually requested here:
@4000ft elevation
solid hardiness zone 7 (though all but two winters checking the data over the last 11 years stay well within zone . It shows in the garden, as for example I have a 25 year old laurus nobilis  (bay laurel) that is usually given a usda rating of 8-11. It sits against a wall so benefits from a micro climate and I need to prune the top regularly to keep it under 15ft (otherwise it would throw shade on my solar panel on the terrace above). But it's younger cousin (10 years) is doing just fine free standing unprotected.