The big advantage is super long photo period. Even so, given your description, I don't know how any crop other than maybe lettuce and radishes and the brassicas, maybe potatoes, will come to fruition without season extending structures.

Even here in the UK tomatoes are a gamble in the open garden. They often do better in a grow bag against a warm wall. Peppers are even harder outside. They tend to be runty and suffer badly in overcast summers. I grow mine exclusively in the greenhouse. Melons - no chance without glass. The easiest squash here is courgettes/zucchini. For butternut you need a southern aspect and a good summer. i start all tomatoes, peppers and squash indoors ie in my green house. You can do it on a windowsill and you do not have to have lights. They are seldom used in the UK although in the US they seem to be standard practice.

You might look at seed catalogues from the UK with cultivars suited to N. Scotland.

This post was edited by florauk on Fri, Jul 26, 13 at 13:05

You would absolutely need to have a tunnel (low or high) at the minimum to grow any kind of warm-weather crop. Even those would fail if cloudy, drizzly weather is the norm. A greenhouse with heat that kicks on during cloudy days and at night would be your best bet. You should aim to have a minimum daytime temp. of 20 C and minimum nighttime temp. of 10 C. The higher, the better.
Among the veggies you listed, cucumbers and summer squash are the most cold-tolerant, but definitely not frost-tolerant.

BTW, don't you have vast reserves of geothermal heat in Iceland? Can you set up a geothermally heated greenhouse? Setup would be pricy, but operation and maintenance would be very cheap.

This post was edited by Slimy_Okra on Fri, Jul 26, 13 at 15:19

Flora, I never use grow-lights either and I seem to do ok. My farmer friend starts everything except the early toms without lights as well.

error - posted to the wrong thread

This post was edited by albert_135 on Fri, Jul 26, 13 at 15:44

OK. As suggested you need some sheltered place , like greenhouse. If I were you I would utilize two free heat sources:
1- SOLAR. Accumulate certain rocks(or other materials that will absorb and store heat to be released when it get cold) inside the greenhouse.(insulate the floor that they are sitting on.

2- GEOTHERMAL: Use the free heat in the ground. In most places ground temperature is over 60 F(=16 C). Circulate air in a duct buried in the ground (very low speed). Depending on the depth and the length of the duct you can draw a lot of free heat energy from the ground, to keep your greenhouse warmer. All you spend is some electricity to run an air circulator. This is not going to be a boom but it will keep the place over , say 40F(= 4.5C).

Another source of heat could be a wood burning stove , if you have cheap fire wood.

"Another source of heat could be a wood burning stove , if you have cheap fire wood."

Seysonn, I guess you haven't read much about Iceland. I believe there are few if any trees - maybe because of the climate described in the OP? Actually, most places at the latitude of Iceland the average ground temp is not close to 60F, but Iceland as noted has a lot of geothermal going on so heating a greenhouse that way might be very feasible.

@pnbrown,
I was just doing a brainstorming thing. lol.
I sure don't know much about Iceland.

>The best advice will likely come from others in Iceland

Yes.

You might try Roma tomatoes. They were the only ones that did well for me when we had an unusually cool and cloudy summer. But not that cool.

If tomatoes are still green when the cold comes you can pick them (before they freeze) and bring them indoors. They will eventually ripen -- some soon, and some months later. Also green tomatoes are a pretty tasty veg.

Hi everyone,

I want to grow outside, not in a greenhouse (everyone does that). And I will grow with a plastic cover, fleece or hoop house, unheated. That's the challenge I want.

Zucchini I can grow outdoors, and it can crop even without protection, but I am looking for better varieties, I just use a conventional one.

I am just looking for varieties, but the conditions of growing, because that I already know. Its varieties, varieties, varieties...

In UK/ Scotland: which varieties of tomatoes, butternut, have you tried?

What about tomato varieties in maritime states of the US, or inland but with cold summers?

And Pumpkins? Any variety to grow under a cold cloudy summer?

Wow, i'm amazed that zucchini will produce in the conditions you describe, without glass or plastic. Average high temperature of closer to 50F than 60F with average low of 45F? Really I can hardly believe it. I think those averages must be incorrect.

Johnnys Selected Seeds sells seeds for cold northern climates with short growing seasons. (Try saying that 10 times, lol) They are in Maine. Their catalog is wonderful. Their seeds are great, too.

I was in Iceland in summer. What a wonderful country! The only vegetables I had there were cucumbers and slightly underripe tomatoes grown in greenhouses. But I saw that people had veggie gardens in their yards with all kinds of cold weather crops that were huge and beautiful. Good luck and have fun.

I agree with trev, who is stating an obvious: warm-weather crops will not produce without that namesake - warm weather.

There is no such thing as a cold-weather cultivar of warm-weather crops, just as there is no human with gills. There are humans who might live a little longer in cold water, not one that can thrive in it.

Hi Trev and everyone,

thanks for your suggestions of varieties.

I am not against greenhouses; I just want to try to push the limits of these vegetables. Instead of containers I raised the beds and cover black soil with clear plastic. Around that, I shield the crops with windbreaks and fleece.

My climate resembles more that of north Scotland and that of northern Canada and northern Alaska. Maine is significantly warmer than we are, and so is Anchorage.

From the four species of cucurbita, I have tried c.maxima (the plants stalls the growth due to cold nights), c.moschata (same), but c.pepo (zucchini) works. I grow it first indoors until it starts flowering, then I move the plants outdoors to a sheltered and sunny spot. They grow very slowly but they crop. This year they have yet to produce the first fruit (summer has been very cold), but last summer I had an average 2-3 fruits per plant. Yes, the average temperatures are correct.

Zucchini and siberian tomatoes can crop some fruits, so this is a promise that with some optimization for soil and air temperature, I can grow more sucessfully.

There are a lot of varieties out there to try, of Russian tomatoes, bush beans, and some varieties of corn and squash. Obviously I am not going to try peppers or eggplants, but the other warm loving crops should be possible to give some harvest, even if tiny.

If you grow it indoors (a greenhouse or solarium?) until flowering, why not leave it in? If a squash plant has reached the flowering stage and you move it to the cool circumstances you describe, there will be very little additional growth. I would think there would be considerably more growth leaving it where ground temp is warmer.

The reason is simple: I have only a conservatory window, so I can grow seed trays and containers, but as tomatoes and squash grow big, then need a larger container, need more watering (and that also brings mosquitos into the house), and they all get white fly and spider mites and eventually suffer damage and die. Also the conservatory gets too hot because of the permanent daylight shining on it. Plants grow more healthy outdoors. If I would have a large greenhouse I would plant them in the ground, but this is not the case. I rent the place so I cannot change it.

These are the reasons for growing outdoors, and I also want the challenge :) So it all comes down in how to create warmer conditions outdoors by use of low tunnels and other ideas, and also by use of special varieties.

Tomatoes and zucchini and even bush beans have already shown me a promise that I can have a crop from them. So I only need to optimize the two things: a plastic frame and the best varieties.

The siberian tomatoes seem to be the best choice, but I still think there could varieties especially adapted not to frost tolerance but to cool and wet summers. I heard that the bush beans provider, can crop in Nunavut, so I will try it. And on the cucurbits, if I can crop some zucchini I believe that perhaps I could do some summer or winter squash as well. This being said, I am left with corn; and I have experimented with the painted mountain variety which indeed survives freezes, but still grows slowly in our summer. Do you understand why I am a believer? ;)

I want to echo an earlier comment re: Johnny's Seeds in Maine. I live just a block or two from the back arm of Morro Bay on the Central Coast of California. The climate is VERY maritime and we live in a stubborn fog pocket as well. My summer daytime temps are generally in the high 60's F, lucky if we move into the low 70's. I grow tomatoes, squash, cucumber, melons in the open, and eggplant, peppers and basil in a PVC framework cube covered with floating row material.

In my experience variety choice is critical as well as a very early start (e.g. I am starting tomato seeds in mid to late January and have them in the ground by the end of March).

There's a lot of trial and error involved and some years are better than others., but that part is true for anywhere.

A few things I've learned:

1. "Big" vegetables are generally not going to ripen. Choose smaller tomatoes, Asian eggplants, single serve melons, small sugar pie type pumpkins, smaller butternut hybrids (Johnny's offers a few), etc.

2. Choose cucumbers that don't need pollination and/or bush varieties that can stay close to the ground where it's warmer. Trellising cukes here just does not work. They get too chilled.

3. Use black landscape fabric for all of the above heat-lovers.

4. Don't give up.

When you get to permanent location that you own, then i would strongly suggest making dug-out solar bunkers. Ideally you'll have a south-facing slope, but if it is flat ground you can dig a pit and use the fill to make a wall on the north side - thicker the better. Insulate the back of the wall with rigid foam board or even hay. The advantage to making them small in footprint is then the glazing can be hinged or removable for hot days and accessing plants, the disadvantage is they heat and cool off faster. A large structure needs operating panels to be usable in the summer - even in iceland I would reckon.

I have one that I use from November through early May when it gets too hot. At latitude 43deg it allows plants to grow slightly even in january without any artificial heat. So in your latitude it would probably move your zone to allow some decent growth for hot weather crops in the summer.

I like the solar bunker idea. I would also suggest lining the insulation layers with black plastic on the inside, for additional heat gain during the day. Those cucurbits and tomatoes will tolerate cool nights if the daytime temps. are sufficiently warm.

Since you already have an idea of what types of plants that you can grow. I would suggest that you look at Denali. http://www.denaliseed.com/ https://bestcoolseeds.com/catalog/vegetables/tomato There have been a series of vegetables especially tomatoes developed in Canada and Alaska. Sub Artic, Early Tanana, Polar Star etc. They are not the best tasting but tolerate close to freezing temps and have short growing seasons. The only winter squash that they recommend is Gold Nugget. I have grown that one and it is a small 2 lb C. maxima type with a bush habit and short DTM.
Johnny's is an excellent company that vends a lot of European seeds. Thier main commercial market is California tho so they do not specifically cater to northern growers, but Denali does.
Of bush beans, Provider #34 has the shortest DTM followed the ever popular Contender.
Of course you should be having a ball with cool season crops.

My advice: do give up. The limit of these vegetables is Minnesota, about 70-75F for sustained periods in the summer. No one grows them farther north. The photoperiod has nothing to do with the exponential dependence of photochemical reactions with temperature and will not help much. And frankly, the vegetables that you can grow at your temperatures (the various leafy greens, the potatoes, beets, carrots and turnips) are both more nutritious and more productive than those you are trying to grow.

Agreed with Glib.

The cool-weather crops will produce abundantly without protection so any efforts with warm-weather ones cannot compete.

It is the same everywhere: poorly-adapted crops cannot compete with well-adapted ones, even with huge efforts in the former case and little in the latter.

I'm gardening in Canada, a little north of the 52nd parallel. Our season is short, but we do get heat for a little while in June and July. This year has been colder than usual and far too wet in the spring.

I've grown the Provider bush beans and have actually found that Improved Tendergreen produces earlier here. You might want to try Scarlet runner beans and a pole bean called Emerite, too. Given a head start indoors, they usually begin producing about the same time as my earliest bush beans.

Racer pumpkins (hybrid maxima) have matured and cured for me by August (planted in late May). That's with more heat than you have, though. I think they would be worth a try, though. They will mature and cure indoors as long as they've at least started turning orange on the vine.

Jackson Classic has been the best pickling cuke for us. They don't seem to succumb under damp, cool conditions like other varieties I've tried, though they prefer at least some heat.

Extra Early Super Sweet is the corn my mother-in-law has grown dependably in this area for decades. It's my first year growing it this year and my plants are shorter than hers for some reason. We'll see how it goes. Fleet has done well for me before, but I always like trying new things.

Glib, I'm somewhat surprised by your statement above... "My advice: do give up. The limit of these vegetables is Minnesota, about 70-75F for sustained periods in the summer. No one grows them farther north." I'm a ways north of Minnesota and grow all the things mentioned here quite well, thanks, with the exception of eggplant and watermelons (and that only because I don't set up tunnels). I have relatives who can grow wonderful, huge, sweet watermelons in Manitoba... still north of Minnesota.

Grow on, segurelha. :)

I grow eggplant without tunnels in Saskatchewan, although they first spend two months growing in a greenhouse before being planted outside for the remaining 3 months.
However, segurelha's summers are downright cold compared to ours...comparable to early May or late September in SK, but with even less sunshine. I suppose there is no harm in experimenting for the fun of it, but a heated greenhouse is absolutely essential to get a decent crop up there.

The impression I get from the OP is that he (or she) is just wanting to push and experiment, so that was the spirit of my reply. :) To be honest, I've only tried growing eggplant once because I don't really like it. *ducksrottentomatoes*

I do not have much to add.. but since My state Maine was mentioned I wanted to give a shout out =)...

Maine isnt the greatest place to grow anything but cool weather crops (even then it still a timing issue, hoping you can plant early enough before the warm humid weather hits in june and july , because it can sizzle things)

Ive had june frosts and late august frosts, but for the most part we get 3 1/2 months give or take roughly of frost free weather, Ive had years though with late august frosts take my toms before they were ripe, and had to ripen them up inside, not ideal.

But I give you kudos for trying! Anybody who would want ot live north and colder then I am , is nuts, sometimes in the middle of the ice and snow i think Im nuts for living here (over 100 inches 9 out of the last ten years here) is nuts lol!

(BTW living farther north doesnt mean colder.. places in alaska do not get colder then me!, neither does the maratimes northeast of me, they are more protected by the ocean more then I am, but still, plenty of places that do get colder, and people live there!)

I suppose the quickest setting toms are the best, so smaller the better probably, most of the beefsteaks take quite awhile to ripen up, I have a few dozen now that are big enough to start ripening, ALL I care about is ONE pefect yellow beefsteak to cut on a hamburger! HA lol.

Silverkelt

Macky,
Hehe, I don't blame you - a lot of the eggplant varieties taste like goat dung (especially the ones available in the grocery store). I only grow the miniature ones - they are very flavourful.

A lot of people here seems to believe that Russian cultivars are supposed to be cold tolerant. This is not exactly the case. Russia is a huge country and has very fertile soils and great growing climate in her southern regions where the main production of tomatoes is happening.
Many so called Russian cultivars are actually Ukranian, and soils and climate there is very very good for tomatoes.
Siberian tomatoes are not of commercial variates. As far as I know there are no tomato farms in Siberia. People grow tomatoes in their home gardens and not in the open ground but in greenhouses.
There are some pockets in Southern Siberia with a warmer microclimate where even apricots and melons can be grown but there are only couple of them.
Good luck in your experiments!

P.S. Born and raised in Southern Siberia

Farther North than MN is all tunnels, green house early starts, lots of fussing, not to mention expenses because a real GH costs $$. I speak as a gardener who wants the most nutrition for the least effort, I also want a crop every year. Direct seeding, no cover is least effort. I do have tunnels, but only in winter to protect standing greens - I have no choice if I want kale in January. I see no reason anymore to grow watermelons to eat in September, when apparently I desire them most in June. Granted I have a site with some shade and heavy soil, and that delays me compared with someone at my latitude, plus pH=9.2 city water, so I try to minimize irrigation, necessary in tunnels. Your site has a way to educate you about what you like. Further, I don't see tomatoes ripening in 50F temperatures anyway.

I understand the sentiment, Glib. I'm a low-input gardener myself. However... I speak as a gardener who is, at this very moment, growing short-season varieties of tomatoes, peppers, squash, cucumbers and corn out in the open, in our native soil - something you're saying is impossible. I don't own a greenhouse. I don't use row covers. I don't use high or low tunnels. The only things I have outside are some cold frames for transitioning starts in the spring. I have a handful of ordinary 4' fluorescents that I use to start a handful of things indoors, but most of my crops are still direct-sown. Just because you "don't see tomatoes ripening in 50F temperatures" doesn't mean it doesn't happen. It does. They do. The original poster knows exactly what they're doing asking about the best varieties for cold, northern climates. The varieties we grow *are* indeed different. You can't keep making such grand assumptions. You don't garden here.

That said, maybe I shouldn't have responded either, given that I don't garden in Iceland. (Slimy_Okra is right - our summers at least have *some* heat to them for a little while.) How many GardenWebers do, though? Which reminds me... thanks for chiming in, tigrikt. Good stuff to know!

I think florauk has great advice... "You might look at seed catalogues from the UK with cultivars suited to N. Scotland." Lots of life-long gardeners over in the UK if my extended family is anything to judge by. :) I'm sure their cold-hardy varieties would be better suited for you than even ours here in Canada. All the best!

segurelha your home page says you live in portugal.

Here some Siberian cultivars, several for open ground. Please remember that July and sometimes even August could be pretty warm there
http://translate.google.com/translate?sl=en?sl=en&tl=en&u=http%3A//vkusniogorod.blogspot.com/2013/01/sorta-pomidorov-dlya-sibiri-ya.html

To add to what macky said, there is a distinct west-east gradient in summer temperatures along the Canada-U.S border east of the Rockies. The hottest summers are in southern Manitoba and North Dakota. Further west, elevation increases and summers get progressively cooler, then warmer again once you're on the west side of the Rockies. Further east, the cooling effect of Lake Superior becomes an issue, with subtle effects in the entire region. Even though the lake is supposed to moderate night temperatures as well, it doesn't - at least not in the summer. The lake doesn't even begin to warm up until August, and even then only into the upper 40s or low 50s. July and August frosts are not uncommon in northern MN and even northern MI, but quite rare in Fargo or Winnipeg. This is despite all these regions being at generally the same latitude. As you proceed into fall and winter, the gradient disappears and then reverses.

This post was edited by Slimy_Okra on Thu, Aug 1, 13 at 21:41

Living on an island myself, I'd be willing to bet that the climate of Iceland cannot be usefully compared to any continental interior at any latitude.