Last spring I had an opportunity to build a hugel bed on a small island in the Baltic Sea. Climate is relatively mild there in comparison to mainland Estonia(zone 5-6). The islands belong to hardiness zone 6-8 and in some areas even 8 hence we can consider us lucky as we can grow some species that won´t thrive or might not even grow at all on the mainland. The though rarely temperature can still drop below -20°C for a short period of time.
I was super enthusiastic when I started to prepare and gather the materials for a hugel bed. My brother mentioned the topic some years ago and recommended that from now on we can just leave all the logs alone, which are not suitable for firewood, and let them rot. In past we usually burnt them during solstice celebrations. Now we just have to make smaller fires 🙂
The main reason to start such a big project was to create more arable land. The soil is very sandy here and summer, lately also in spring season it can be very dry for too long. We have some about 70 year-old alder trees nearby which have increased organic matter levels compared to some other parts of island where only conifers grow and one has to import decent soil to their garden in order to grow something different than rododendrons and junipers.
There are loads of recommendations how to make a hugel bed and it is not all that difficult if you follow some basic “rules” like avoid using softwood (pine, spruce) and wood that will decompose very slowly (redcedar). That last one we don´t have growing on the island. Also it is important that the bed gets maximum amount of sun in the course of the day. There is plenty of information out there.
As the plot is just 700 m from the sea the soil is relatively sandy and therefor quite easy to dig. My brother collected all the rotting wood from the plot and I did the rest (almost). It was a good workout and took me 5 days but I was happy plus my hands got stronger.
I dag a 50 cm deep trench and pushed the largest logs in there. The bottom ones were almost falling apart but some of the larger branches, which I added to the top weren´t and that was a mistake. I know that raw wood robs too much nitrogen while decomposing. After that I added the layer of decaying chipped wood, leaves, hay and bark. On top of that seaweed, mostly bladderwrack (Fucus vesiculosus) and I couldn´t bother washing it before as Baltic Sea’s salinity(ca. 0.8%) is much lower than that of ocean water. And on the very top I scooped compost and soil.
At the beginning the dimentions of the mound were 2 m x 80 cm x 8 m but it sags down day by day. Jumping on the mound slightly accelerated the process. Growing surface became too narrow (u 40 cm) I´m continuously adding more soil and seaweed to the sides.
I know that I shoud´ve started small and could´ve rent a small mechanical digger for building such a big mound but I couldn´t resist as I had so much materials in hand. If anyone decides to go for it I strongly recommend to make a small scale one first.
I´ve read that moles and muskrats might think that a mound like this is a perfect place to live. We don´t have any moles on the island and haven´t seen any signs of muskrats either. Though in spring my brother saw a non-poisonous grass snake crawling on top of the mound to catch the sun. According to locals seeing one is rather sign of fortune. Most probably because they keep some pests under control. I like those snakes with yellow cheeks. Also some wood ants(Formica) moved in but it is not sure yet if they are going to stayh. I´ve always loved antshwere kids we used to spend hours feeding them fruits and sugat and watching them running around. They also keep pests away, especially ticks.
Spring was extremely dry and as we hadn´t managed to cover the bed with enough soil and mulch only runner beans, basil, mangold and zucchini happily grew there. I must say they needed quite a lot of watering at the beginning but later less than other plants in lower beds. Mostly rain watered them and we didn´t have to worry.
Here is a video by Philip Forrer of making smaller scale hugel bed. The forest and climate are very similar to our conditions on the island.
We have continually added soil, green mulch and seaweed to the sides to make the mound a bit flatter to have more growing surfice. I hope that the 2nd season will be more productive and less labour intensive.