Is hugelkultur in Scandinavia a good idea?

Hugelkultur is not something that is familiar to most people in Scandinavia, but that does not mean it isn’t a good idea, quite the opposite actually in my opinion.

The climate in Scandinavia is, at least near the coast, warmer than one would expect due to the Gulf Stream, but there are a huge variations, so first step would be to identify what one can grow in our hugelkultur.

USDA Hardiness Zone system

The USDA Hardiness Zone Map separates the USA into 11 different planting zones. We need a way to compare the climate where you live with the climate where a plant is known to grow well. That’s why climate zone maps were created. Zone maps are guidelines that show where various permanent landscape plants can most likely succeed growing as intended. , The plant must withstand the all year climate in your area, including lowest and highest temperatures and the amount and distribution of rainfall. Climate change and natural extreme conditions and very local conditions should be taken into account so that your annuals, perennials, and trees can survive and grow year after year

Many resources online refers to the US hardiness zones, but what are the hardiness zone that you live in can be difficult to find as these zones are not universally adopted. Many have their own different zones and they can be very useful to be aware of when you go to a nursery for examples, but for looking at online resources I find knowing about the US hardiness zones is more important for planning and learning purposes.

This site contains a lot of maps and information on quite a few places outside the US and an ranking of zones. It marked my place as 7b

https://www.plantmaps.com

Raised hugelkultur bed heat up quick in spring

A huge advantage of a raised bed is that since it’s elevated it doesn’t take that long for the ground frost to let go and the decomposition will add extra heat from within. This will especially be so if you have added manure to the hugelkultur as you build it.

Some plants thrive extra when their roots are warm, like beans, corn, cucumbers, tomatoes, and squash. Personally I have had little success with corn so far, but will attempt it again, as I love and eat so much corn it just makes sense. Grow what you love to eat if you can.

Hugelkultur as moisture control

I had never thought I would need to water much where I live as rain is our default weather, but the summer of 2018 opened my and other’s eyes. I have never watered our fruit trees after the first year of planting them, but this previous summer I did it every day for weeks. It paid off, our trees gave us so much fruit. This work I hope to avoid in the future, so I will construct hugelkultur near or around them all.

Feeding the soil, not the plants

In parts of Scandinavia the soil is quite poor or a very thin layer of good soil, this is also the case many other places in the world. One could transport good soil from other places, but then those places will not have soil, so instead we should try to create good soil by relying on the processes that creates good soil.

Natural and healthy soil contains a universe of minute creatures eating and excreting. Bacteria,  fungi, nematodes and worms all feed on each other and all of them pee and poop. Inside our hugelkultur these are the processes we are relying on and rooting for.

Mycorrhiza

The part of them that are not consumed can become a vault of nutrients for plants, either directly or indirectly. Roots actually excrete substances that attract bacteria and fungus to gather where they are, so that they can take advantage of this game, too. Most plants have symbiotic relationship like this and Wikipedia describes it like this:

“A mycorrhiza is the symbiotic association between a green plant and a fungus. The plant captures the energy coming from the sun by means of its chlorophyll and supplies it to the fungus, and the fungus supplies water and mineral nutrients taken from the soil to the plant. Mycorrhizas are located in the roots of the plant.”

Source: https://en.wikipedia.org/wiki/Mycorrhiza

Since some bacteria and fungus can directly feed plants in exchange for treats the plant provides we should work with the system and not fight it. Some plants even have fungus that can extend its roots, expanding the reach of the plant to find more water and nutrients.
If we don’t make sure the local ecosystem in our soil is taken care of, by use of chemical fertilizers and poisons, the soil will not have the proper natural tools to make that happen and then our soil and hugelkultur will not get the aid of our army of critters in the soil. Having a hugelkultur can help speed up these processes and especially in a colder climate, like in Scandinavia, as the hugelkultur can provide more heat due to the composting processes in it.

Safe…ish plants to grow in a Scandinavian hugelkultur

Some warn that the first year one might as well just let it rest, but in my view, unless you do it very late in the season, I don’t think this is a must. The yield will probably be higher the second season, but if you have access to some good soil and add that around the plants you most likely should get some growth at least. We planted broccoli and that is one thing I’ve seen a lot of people warn against as a first season crop, but boy was that a huge success. Never had such a success with them before, and they produced well into after the first few days of frost and snow.

Since Scandinavia covers a lot of different climatic zones it is important that you do a bit of research and perhaps keep track of your progress in a journal, like this one.

Fruit trees

Apples, pear, plum and cherry trees are very common to plant and have in gardens in Scandinavia. These and other fruit trees one might find suitable can benefit from the environment hugelkultur beds will provide.
If one has a very large hugelkultur bed most people with experience with permaculture would most likely warn about planting trees in the middle of such a mound. Trees should be planted at the edge of hugelkultur beds to benefit from collected moisture and nutrients. The trees may also benefit from the wind breaking aspect the mounds might prove. This is something you won’t get if you attempt to plant trees on the top of the raised beds.

Edible bushes and shrubs

We also have berry bushes such as blueberry bushes, raspberry bushes, currant shrubs, black currant bushes and gooseberry bushes.

Blueberry bushes

Blueberry bushes, the American variant, and not the wild local Bilberry, are easy to grow in Scandinavia. A lot of people seem to prefer the bilberry over Blueberry for taste, but they’re not always as accible as having a few blueberry bushes in ones own garden.

So far I’ve not planted blueberry in or near a hugelkultur myself, but I have this on my rather long todo-list. One of my blueberries have never done particular well, so I consider transplanting it.

Raspberry

Raspberries are easy to grow, so easy that they can spread like a weed from their roots, but if you have a raised hugelkultur bed with a solid outer frame they shouldn’t self-propagate outside of the area you’d want them to grow. Just make sure to remove any new shoots that might start growing outside your raised bed.

There are both summer and autumn-fruiting varieties. If you have a mix of them you’ll extend the harvesting season from midsummer until near winter. Raspberries thrive in moisture-retentive, but well-drained soil. They prefer fertile, slightly acidic soils, and weed free growing conditions, so they would seem to be perfect for a raised bed.

If you end up with more than what you can eat fresh, raspberries also freeze well. A good idea is to lay them out flat in a thin layer in your freezer on a tray and when they have frozen pour them into ziplock bags. This way it is very easy to handle them later on, if you want to decorate a cake during the winter or add a specific amount to your homemade cereal mix, as examples. They also make wonderful jams and sauces. They can easily be used frozen for these purposes, so no need to do all such work when you really should be harvesting and enjoying the summer or late fall.
Apart from what we eat fresh, we mainly use it as juice, either in a mix with other berries or fruit or as strawberry juice.

Currants & Gooseberry

Black & red currant and gooseberry are closely related so we’ll group them together here. One can easily seperate currants and gooseberries from eachother by looking at the canes and fruit. Gooseberry canes usually produce a spine at each leaf node and bear roughly thumb-sized berries singly or in groups of two or three. Currant canes does not have the spines and bear 8 to 30 pea-sized berries in clusters.

These fruits are excellent for the home gardener as they are relatively trouble-free and produce quite a large amount of highly nutritious fruit and why they are probably the most common berry to have in Norwegian gardens. Currants are divided into black, red and white types with many varieties to choose from. In general, blackcurrants tend to be cooked as they are quite tart raw, but red currants and white currants are more likely to be used fresh.

Currant bushes live easily 12 to 15 years, so one better make sure one give them the best conditions by making sure the soil is as ideal for them as possible. They require well-drained soil with lots of organic matter and this does sound like hugelkultur to me, but I wouldn’t put it on the top of one, since it lives for so long and the hugelkultur
Currants grow well in sun or partial shade, the more sun they get the larger the harvest will be, but they do not like it too warm. Plants may drop their leaves when temperatures exceed 29°C (85°F ) for an extended period of time. Some areas in Scandinavia this might be an issue.

Currants can be planted slightly deeper than they grew in their nursery container, this is quite the opposite of what one would do with a tree. Space them 4 to 5 feet apart. Water rigorously after planting and apply a good layer of mulch of organic origin around the plants.
Mulching, as one normally should and would do in an organic garden, helps keep the soil moist and cool, and prevents competition from weeds. As always one should add fresh mulch every year to bring it up to the proper depth. This is something one of the few tasks one should do with hugelkultur environments. As for watering, it depends on the state your hugelkultur is, but in the first year of the bush I would water it regularly, but from the second year on I would just leave it alone unless it’s an unusually dry and warm period.

Pruning currant shrubs in very early spring by removing the oldest wood is helpful for the plant as well in both maintaining its form and lead to a bigger, healthier harvest.

These plants may easily suffer from lack of nitrogen, so having some sort of nitrogen fixation plants, like legumes (beans and peas) or goumi berry will help. As usual; don’t overdo it.

Something quite new: Goumi berry

In my refrigerator, I have some Goumi berry (Elaeagnus multiflora) seeds for cold stratification. I will attempt to grow these and plant them in our garden and also at my in-laws cabin. That cabin is up in the mountain where the soil is very poor and the nitrogen fixing aspect of this plant will come in handy for the hugelkultur I plan to set up there.

Vegetables

More or all vegetables where one harvest above ground should work great in a hugelkultur bed. Some are generally recommended to avoid all toghether, like carrots, and others might work after a few years.

Potatos

Potatoes are quite often on lists of things to not plant, but there are others who disagree, but often under specific conditions. If you don’t mind a small harvest of potatoes, and mainly look on them as means to improve the soil and you just harvest what you can spot and just leave the potatoes that might have spouted inaccessable between roots and branches far below, then sure go ahead plant potatoes. This idea appeals to me.

Broccoli 

Another vegetable I’ve seen on “do not plant first year” lists is broccoli. My jaw dropped as we did this year, and I have never seen or tasted better broccoli than the ones we planted in our first year hugelkultur bed. The reason why our broccoli did so well the first year might be because we had access to some prime compost, that we generously poured into the mound.

Physalis

My daughter wanted to test physalis, and they grew really tall and impressive, but winter frost came before the berries were ripe, so they all died. That was a bit sad as I really had hoped for some ice cream decorated with them.

These are just a few examples, when I have more detailed information and experience with various vegetables in hugelkultur I will post more information.

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