The greatest growth rate was in the Hugelbed with topsoil addition. The hugelbed was embedded 1 foot in clay 8 feet wide, filled with poplar strips and covered with the clay reserved from the trench. Grass clippings, and topsoil (peat moss and sand) were added and a light mulch finished the bed.
Growth rates in the hugelbed with no topsoil addition were similar to the rates seen in swale beds. Probably about ten percent less growth than the Hugelbed with topsoil addition.
Growth rates for seedlings heavily mulched in baresoil showed about one third less growth than the top performers in the hugelbeds.
The controls planted in bare soil with no mulch showed 50% less growth than the best performers.
This experimentation seems to confirm that, in my situation at least, Hugelbeds have significant growth benefits.
I also tried adding some fish scraps (ie heads and guts) to some of the mini swale beds and while growth was extreme, it was leggy and susceptible to the wind.
In the future I will probably add fish guts to my hugelbeds on top or under the wood, so that plants can access it slowly over time. Despite being in bear country and seeing bears on my property, it seems that after two years of observation, the bears are not interested at all in digging up the fish guts. My dogs, on the other hand, just love to roll in them. Yuck!!!
I have a lot of work ahead of me, but I will follow up with pictures and more results as we get them. Hopefully, this is of some use to you guys.
Hugelkultur bed average growth: 2013 growth - 22.0 cm Total two year growth average - 45.3 cm
Non Hugelkultur beds av growth: 2013 growth 10.8 cm Total two year growth average - 31.6 cm
Average growth in the following (2013/two year (in cm)):
Hugel w/ Top Soil - 24.5 / 45.6
Hugel w/out Top Soil - 17.6 / 44.7
Disturbed clay - 11.8 / 36.5
Heavy mulch - 13.5 / 42.5 * experienced 30% plant loss
Bare Earth (control) - 9.9 / 27.4
None of this should a surprise to any of us. To be clear, no water was applied to the site other than regular rainfall. This year (2013) we had over a month of no rain at all (and a heavy forest fire season as a result.)
The growth rate was not what I had hoped and another conclusion I have made through this experiment is that it is more financially efficient to buy three year old nursery stock in pots than it is to buy bare root stock seedlings. I will miss out on the three or four years of revenue that I could be amassing already. Things like this could make or break a bigger operation. At the moment we have invested close to $20,000 (mostly earthworks and nursery stock), and haven't seen any revenue come in yet and likely won't see much for a few more years. As we add stock to our orchard, we will rely more on potted plants that have sufficient energy momentum to get them fully established and fruiting the following year. Each situation is different eh?
Our potted stock (Haskap, currants, gooseberries, and a few saskatoons) looks as though it will be fruiting heavily next year. Finally we will be able to eat the fruits of our labours.
Thanks for posting this and I look forward to your pictures.
What you did here is super valuable - you quantified results in different circumstances in a challenging climate zone. I live in a challenging (yet opposite of yours) climate zone as well (9b - hot desert). Planting in swales works great, planting on hugels/raised anything - dries out and heats up too fast. Again - just the opposite of you! But it makes sense, climatically.
Also - just wanted to say my hat (if I was wearing one) is off to you for experimenting and succeeding in Zone 1. That's really inspirational! Keep it up.
Miles Flansburg wrote:Thanks for the info Jeff !
Is it only saskatoons planted in the hugel?
I am hoping to build one in the next summer or two and saskatoons are on my list, as well as raspberries,apples, all sorts of veggies and wild locals.
No I only measured the saskatoons because they are the most numerous on site. I have interplanted them with sea buckthorn, goji, plum, rhubarb, haskap, currants, chives, nanking cherry, hardy apples, and elderberry... i would like to use some more nitrogen fixers... perhaps siberian pea shrub.
I have alfalfa, clover buckwheat and daikon in the beds as well
Congratulations on your project! I enjoyed your Zone 1 humor.
Which elderberry did you plant? Also which apple variety?
I'm interested in how the goji produces for you...I have some in zone 3...grows and flowers well but have only harvested maybe 6 or 7 fruits.
All the best
Wonderful,another Gandhi enthusiast....I've learned so much from him/ his life...still learning.