Cover crop/Nitrogen fixers advice for Raised Hugelkulture

[SQWIB]

Last year I built a few Hugelkulture beds and in the fall planted some oregano and thyme for a perennial cover crop. I will be building another 20' wide bed. I was planning on doing the same thing

Existing beds are, bottom to top: Logs, Twigs, Hedge trimmings, Existing top soil, Wood mulch, composted Manure, top soil, Shredded wood mulch.

New beds will be, bottom to top" Logs, Twigs, leaves, Existing top soil, Garden compost, Wood mulch, composted Manure, top soil, Shredded wood mulch.
These beds will be for Eggplant, peppers, tomatoes, lettuces and herbs.

I have a few questions I was hoping you guys could help out with.

Should I also plant some kind of Nitrogen Fixers like Hairy Vetch in the fall along with the perennial cover crops? Do I even need them?
Can I plant some in the spring? And if so can I plant my regular veggies alongside the nitrogen fixers?


Here is the first bed.





Fall


Here is the 2nd bed.




Fall


I planted a mish-mosh of veggies that done fairly well, I was a but surprised being their first year, July 15th

[applestar]

Very nice! I'm impressed by how decorative you made them. Looks like they did very well for you, too.

Yep. I would grow nitrogen fixers. Vetch for winter hardiness -- but they can reseed if you miss cutting/turning them in, or fava beans and peas in early spring.

Nasturtiums in one and luffahs, okra and eggplants in another grew fantastically this past summer in mine -- I think my thread is in raised beds forum -- first year were tomatoes and sunflowers with pole beans climbing the sunflowers, with some peppers and basils.

[SQWIB]

Very nice! I'm impressed by how decorative you made them. Looks like they did very well for you, too.

Yep. I would grow nitrogen fixers. Vetch for winter hardiness -- but they can reseed if you miss cutting/turning them in, or fava beans and peas in early spring.

Nasturtiums in one and luffahs, okra and eggplants in another grew fantastically this past summer in mine -- I think my thread is in raised beds forum -- first year were tomatoes and sunflowers with pole beans climbing the sunflowers, with some peppers and basils.

Is it too late for the vetch, I'm in zone 7A?
I also have a legume mix of seeds I use for sprouts, could I use those in spring? Do I leave the spring Nitrogen Fixers keep growing when I plant the Peppers, Eggplants and Tomatoes?

I'll order some vetch and Fava beans.

I'll have to find your post and checkout your garden
Thanks

[imafan26]

Some legumes are better than others for nitrogen fixing. It is also better to inoculate the legume first to increase nodulation especially if you don't know what kind of soil microbes you have present.

As far as organic gardening goes, it is not once and done. You will have to supplement with compost every year as the materials in your bed decomposes. Compost is not fertilizer but it would be best to get a soil test and ask for organic recommendations for fertilizer. Cowpeas and vetch are the usual ones recommended for green manure. I don't use vetch, but I do use cowpea. It is ready to till in at first flowering or about 6 weeks old. Buckwheat adds biomass and is ready to till in at six weeks. In a cooler zone you could use winter rye. Other choices for organic nitrogen would be blood meal, organic lawn food, cottonseed meal, feather meal, or composted manure.

[rainbowgardener]

Perennial and cover crop are mutually exclusive. A cover plant is something quick growing that you plant seeds of at or near the end of the season. Let it grow for awhile and then in late winter/early spring turn it under, into the soil. Then the nutrients in the plant are released into the soil as the plant breaks down. You are not going to turn perennials under.

Your beds seem very heavy on the woody/ high carbon stuff and light on any nitrogen sources. I think you are going to need to keep adding lots of nitrogen sources, not only a nitrogen fixing cover crop, but lots more through the season - compost, blood meal, feather meal, worm castings, fish emulsion, etc.

[SQWIB]

Perennial and cover crop are mutually exclusive. A cover plant is something quick growing that you plant seeds of at or near the end of the season. Let it grow for awhile and then in late winter/early spring turn it under, into the soil. Then the nutrients in the plant are released into the soil as the plant breaks down. You are not going to turn perennials under.

Your beds seem very heavy on the woody/ high carbon stuff and light on any nitrogen sources. I think you are going to need to keep adding lots of nitrogen sources, not only a nitrogen fixing cover crop, but lots more through the season - compost, blood meal, feather meal, worm castings, fish emulsion, etc.

Yes they are mostly browns/carbon, I add composted manure each season and some 10-10-10 in the beginning of the season and middle of the season. This will be my first year adding my own compost and will also be adding compost from https://www.phila.gov/ParksandRecreation ... enter.aspx

I planted the perennial cover crops after reading an article by DR. Elaine Ingham, not sure if it's bioremediation https://www.soilfoodweb.com/FAQ.html
Article sections,
(Should I Use Annual Cover Crops When Growing A Rotation of Tomatoes, Garlic, and Brassicas?)
and
(What Cover Crops Should I Use Instead Of Annual Cover Crops? Do I Still Need To Till?)

The cover crops are not meant to be turned in, they are to be left alone and the veggie plants will be planted in them, if that makes sense.
I purchased some Milorganite for nitrogen that I wanted to add to the beds during the winter but after reading about the Milorganite, I may just use it for my tree and shrubs.

[applestar]

Not strictly according to definition of covercrops and not the best method for full advantage, but what I do is grow vetch more or less naturally -- they easily self seed --seed pods pop and scatter seeds when dry. They germinate and re-grow in cold/cool temp -- I would just scatter the seeds now where you want them and they'll come up when weather is suitable. Maybe lightly cover so birds and critters don't discover the seeds and think you are feeding them. I find they pull out easily -- dry hard soil and they break off leaving roots and lower stem which will grow back later but thats ok -- use the vines as mulch or compost, let seeds develop if you want or yank again before. When soil is soft, roots will come up and you will see the rhizobium nodules -- inspect to see how well inoculated they are.

I like sowing early maturing 55 days or so short/dwarf <28" peas where I will grow tomatoes, peppers, eggplants. Leave some room to plant tomatoes -- staggered in double row or gaps within the row, one side of wide row, etc. -- support the peas as necessary -- sometimes just bunch up with string to get out if way of transplants.

Taller peas and fava supported with string trellis work well in an alternating rows with deeper rooted crops like corn. But they are later maturing, so take into account when succession planting the next crop.

Typically peas are still continuing to grow and mature when corn then tomatoes then eggplants and peppers are planted so you want to plant in such a way -- distance/height that thriving vines are not shading or taking nutrients. But as soon as peas are done/start to dry up, you can cut them off at soil level. Use the vines as pea vine "straw" --more like hay as green-- mulch.

I also grow bush beans under (in front of) tall trellised indeterminate and cherry tomatoes. Last year I tried adzuki (actually grew up to 24 inches) and was very happy with results. I tried edamame one year but they didn't grow well. I read later that edamame needs more fertile soil so maybe couldn't compete.


If you haven't grown legumes last season, be sure to use appropriate inoculants.

For summer covercrop, I really like buckwheat. Very easy to knock over and crimp as mulch.

[SQWIB]

Just wanted to update this, the beds have been doing well without the addition (STORE BOUGHT) fertilizer and black kow, since the initial startup of each bed.
IIRC, Last seasons end 2017, added rabbit manure, old potting mix, compost from the recycle center, coffee grounds and planted some crimson clover and oats. Then in the late winter/early spring, I mulched with Bio-char (charged with urea), leaves and shredded mulch.
This season 2018, I started my crops by under planted with chia and crimson clover and during the growing season, chop and drop, trench composting, add coffee grounds and rabbit manure /bedding when it becomes available, then in late summer/early fall I added some old potting mix, planted Crimson Clover, Oats and a mix of legumes as a cover crop.
The late winter/early spring when everything is dead and decomposing, I will top lightly with Bio-Char (charged), potash (wood ash), leaves, my compost and may add some compost from the recycle center.

[imafan26]

Sounds like a winning recipe. I would have planted a legume as a first crop on a new bed especially with so much carbon in the bed. Did you supplement the first crop with anything like fish emulsion, blood meal or manure tea to give it extra nitrogen during the growing season?

[SQWIB]

Sounds like a winning recipe. I would have planted a legume as a first crop on a new bed especially with so much carbon in the bed. Did you supplement the first crop with anything like fish emulsion, blood meal or manure tea to give it extra nitrogen during the growing season?

Not that I recall, maybe urea.
I'm gonna check my notes again.

[rainbowgardener]

I'd love to see an update on how these beds did!

In the meantime, I am starting a (sort of ) hugelkulture bed myself for the first time.

I have been in the process of building a 20 ft diameter circular raised bed out of interlocking concrete blocks, which is in four quarters with paths in between. I have had the first two quarters built, and now am (finally!) working on the third one. (In the meantime we painted the whole outside of our house, built a picket fence around all the rectangular veggie beds, and refinished our 400 sq feet of deck.)

So for the third bed, I am laying down a bottom layer of old rotting boards and then covering them with sod I dug out of the area.
Here's how it is looking so far:

The chicken is standing on top of some of the boards. If you click to enlarge it, the boards show up better. (Added bonus, if you look closely in the background are most of the rest of our chickens, standing next to the fence that encloses their coop. )
Once the bed is built, I will fill it with more dirt (digging out the paths around the other two quarters, which have gotten weedy in the meantime), some fall leaves and used straw bedding mulch, some manure, and some premium topsoil from my bulk supplier. (These guys are 3 miles from me and provide high quality topsoil, mulch, graded gravel, etc https://www.windwoodbulk.com/ )

Comments?

Just for reference, here's a photo of the first two quarters

[SQWIB]

Rainbow, the beds are doing great.
I have been covercropping late summer and topping with whatever I can get my hands on when everything dies back.


First year with this Hugelkultur bed
Mid July 2016





First year with this Hugelkultur bed
Late July 2017



Cover crop Mid October 2017




August 2018



October 2018 cover crop


November 2018 cover crop




August 2019






Cove Crops Mid September 2019


October 23rd, 2019


November 21st, 2018




I think the in situ composting in the winter, has really helped the beds out.

Composting when beds are still growing cover crops








Composting late winter





The last few years I added a lot of Charged Coarse Bio-char and went real heavy on organic matter.

[SQWIB]

I'd love to see an update on how these beds did!

In the meantime, I am starting a (sort of ) hugelkulture bed myself for the first time.

I have been in the process of building a 20 ft diameter circular raised bed out of interlocking concrete blocks, which is in four quarters with paths in between. I have had the first two quarters built, and now am (finally!) working on the third one. (In the meantime we painted the whole outside of our house, built a picket fence around all the rectangular veggie beds, and refinished our 400 sq feet of deck.)

So for the third bed, I am laying down a bottom layer of old rotting boards and then covering them with sod I dug out of the area.
Here's how it is looking so far:

hugulkultur bed.jpg

The chicken is standing on top of some of the boards. If you click to enlarge it, the boards show up better. (Added bonus, if you look closely in the background are most of the rest of our chickens, standing next to the fence that encloses their coop. )
Once the bed is built, I will fill it with more dirt (digging out the paths around the other two quarters, which have gotten weedy in the meantime), some fall leaves and used straw bedding mulch, some manure, and some premium topsoil from my bulk supplier. (These guys are 3 miles from me and provide high quality topsoil, mulch, graded gravel, etc https://www.windwoodbulk.com/ )

Comments?

Just for reference, here's a photo of the first two quarters

IMG_1787.JPG

I have a few comments,
So far everything is looking good

Layer everything making sure to use as much native soil as you can.

Top soil is IMHO is not worth the cost, time and effort

[imafan26]

I have done trench composting and this is my first time actually trying hugelkultur in one of the beds. We don't have the same tree species that is used in colder climates. I did get the "logs" actually mostly smaller limbs and branches from trees that were cut about 2-4 years ago and have been slowly left to do its thing. The termites have not bothered them so that is why I chose these pieces. The trees were mostly china dolls and some of the fruit trees from the orchard and probably some monkey pod which is why it takes so long to break down. Partially decomposed compost that is made on site has been placed on top of it. It is now covered and will take another 6 months before it can be planted.

That is mainly because that is how long it normally takes for a trench composted bed to be ready to plant. Although, I do add ammonium sulfate to the bed as a nitrogen source when it is ready before I plant. It is not organic, but we have tested the bed and the pH 7.8 is high, the bed is very high in phosphorus and high in potassium and other tested elements are within the normal range. Nitrogen, based on the size of the plants that grow in the compost without the addition of nitrogen, is moderate to low. It is enough to get a healthy crop but they are 1/3 the size they are expected to be. The soil test does not measure nitrogen directly, tissue samples were adequate. I just like bigger crops, so I use the most efficient nitrogen available and it does contain sulfur to help acidify the ph as well. There is a lot of carbon in the compost and I don't like to supplement every week. Nitrogen is essentially only given once for a short crop of lettuce, chard, and arrowroot (perennial).

The problem is that the second crop is usually much smaller, despite adding additional compost. I end up having to make another trench compost bed which takes another 5-6 months before it can be planted. In the tropics with a 365 day growing season, it is a waste of valuable space, especially since space is usually a premium. I usually don't add more nitrogen, for second crops, but I have to for the trench composted bed.

I am interested to hear how you are able to keep up productivity in your beds as they get older. Do older beds produce as well or do you have to redo them after awhile to renew them?

I do cover crops, but even my cover crops need to be given nitrogen or they don't do well either. My soil is fungal dominant and it I have to inoculate legumes every time or nodulation is poor 0-4 without inoculation 8-12 nodules with inoculation. Cover crops that do the best for me are cow peas and buckwheat. I have used sunhemp, but it is very hard to get the roots out. They are tilled under at flowering, but I will keep some cowpeas for seeds for another crop. Someone actually does like to eat them.
The bees like the buckwheat flowers and it feeds beneficial insects but it becomes a weed if it is allowed to reseed.

[SQWIB]

The first year I added 10-10-10 because I was worried about Nitrogen Tie Up, this year I added a minimal amount of 10-10-10 and some ash to the beds, I usually only fertilize my air pots and planters.

I'm under the impression (from all of my research) that the Hugelkultur beds get better each year and expect good results at 3-5 years with the first year being the worst and improving slightly the 2nd year, however, the beds seem to be fine every year including the initial build year, but I really can't say if its been better or worse, this year was really bad for my peppers and eggplants in the bed but I believe that was my fault, the tomato plants took off!
Water retention has definitely gotten better.

[imafan26]

Thanks. I actually am using the branches and limbs as a drainage layer. During the rainy season when rain can last for a week, the beds can flood also for a week or more. I am hoping the logs will help as a drain layer to keep the beds higher and drier. It will be interesting to see if the productivity also improves over time.