Raised bed advice for good drainage, high productivity and low budget

I live in the rainy Basque Country of Spain. The climate here is a bit like the southwest of England but a bit sunnier and warmer, or maybe Seattle with the rainfall more even throughout the year.

My town has just started an allotment/community garden program. Each person gets a small plot for 4 years, then there is another lottery and you may end up on another plot or out of the program altogether. My plot is about 30 square meters (300 sq.ft.) in a irregular shape, it's on a gentle slope, and gets full sun all day. The parcels are on bare land that was graded about 3 or 4 years ago and mine is hard pan clay with plenty of rocks. There are a lot of restrictions about what you can do there: no greenhouses or cold frames, no permanent-ish structures of any kind, no irrigation systems, no trees, bushes are a bit iffy, they basically want you to grow annuals. And all organic of course.

My main objective is to feed two people's voracious green+vegetable juice habit as year-round as possible, and then as much of the rest of our veggies as I can, and of course save the world, make a paradise for pollinators and all that jazz. I also need to plan for neglect as we're usually gone elsewhere for 2-3 weeks every August (of all horrible months to be away from your garden) so I'm interested in trying to ward off total disaster while we're gone. Since the plot is small it needs to be super-productive.

I'm thinking of the following and would love to get experienced people's advice as this is my first ambitious veggie garden

--No time to cover and let anything sit/decompose, got to put it together and stick the plants in quickly to take advantage of this season (I only have 4 seasons total)
--No dig, a la Charles Dowding, and no (cardboard/newspaper) weed barrier, just smother the few weeds that have poked up through the hard pan with what goes on top
--Raised beds, 1.20m (4 feet) wide and 0.4m or 0.5m (16-20") tall, oriented north-south (deepish to allow for carrots etc. sprinkled here and there)
--Sides of beds will be recycled burlap coffee sacks, overlapping a bit and supported on stakes. Never seen it done before but seems like it should work for a while.
--Lasagna recipe: a bit of EM and aged manure on the undug hard pan, 10cm/4" of hay, 2cm/1" of manure, 20cm/8" of straw, 2cm/1" more manure, topped by 10cm/4" or more good urban compost
--Biochar: Just a touch sprinkled throughout the layers -- a handful here, a handful there (figure with all our rain I need to try to retain nutrients)
--EM-ed water generously throughout all layers, especially straw and hay
--Inoculate non-brassica plant roots and seeds with mycorrhizae (to help them survive August neglect)
--Beds for tall stuff: Along the northwest and northeast sides, where I don't have access to the back side, a 60cm/2-foot-wide bed for tall and trellised things, there they won't shade the other things
--Intersperse veggies/herbs/beneficials rather than planting say all the tomatoes in one place, would like to get a 2-storey deal going but don't quite know how. Anyone got a good guide?
--Since I'm interspersing randomly, not follow any particular crop rotation pattern
--Mulch maybe with pine needles, something that doesn't appeal too much to slugs, which are a problem here
--Maybe a more serious mulch while we're gone in August -- 20cm/8" of very wet straw or something


Stuff I'm worried about:

--Is my idea to use coffee sacks for the sides of the beds crazy? I figure they'll last maybe 2 years and then rot and have to be replaced.
--Any bright ideas to help the garden through the August neglect? Might be beastly hot and dry, might have torrential rains, who knows?
--What's a good mulch alternative where slugs are a problem? Are pine needles a good idea?
--The no digging and no weed barrier thing. Anyone care to give me reports from their own experience? Drainage is important here as it can rain a lot, and for weeks at a time.
--The layered approach to intensive gardening -- not sure where to learn to do it well
--Will it really be a disaster if I happen to randomly plant a tomato plant in the same spot three years in a row?
--Any ideas to make the "lasagna" layers break down and create a nice environment more quickly as I'm going to start planting right away. I know this year won't be too productive but would like to help it along as much as I can. Note: I have essentially unlimited access to OK-quality urban compost.

OK, sorry for the long post, very appreciative of any insights or suggestions you can offer!

Dave

Howdy Dave, welcome to permies!

Have you considered growing a few edible weeds in there too?

https://permies.com/t/38326/gardening-beginners/plant-vegetables-weeds-nutritious

I would be gnashing my teeth at the four-year rule, who on earth thought that one up! Not much room there for any long-term investment in soil health. OK so you should be inheriting a fairly clear plot in the next lottery, unlike the rubbish-infested ("this'll come in useful now where did I put it") tangle you can get in the traditional British system, but I suspect your neighbours may look even on your proposed system with a rather jaundiced eye, if their idea of the right way to look after a plot is dig dig dig, "weeds" out, fertiliser in. On the other hand you may be able to inspire them away from that.

I was thinking of artichokes because they are perennial but not "bushes" so in year four you could be raising from seed ready for the move. Strawberries similarly (runners). Rhubarb? Fennel comes well from seed and is good for pollinators.

My approach to rotation is to rotate, but rotate guilds and overlap crops. So instead of a row of onions and a row of carrots, I am hoping for widely spaced onions with carrots sprinkled between, plus occasional poppies and calendula where they choose to come up, and the brassicas for the coming winter growing on hidden in there as well. In autumn, the broad beans will be sown and be covering the soil under the brassicas by spring. This is still a work in progress.

How can you rotate effectively though, if in year four you are going to be dumped on someone else's abandoned system?

I think you need to break up the hard pan. I don't like digging, but sometimes you have to do something cataclysmic to rectify neglect and get the system healthy again.

Dave Forrest wrote:
--Intersperse veggies/herbs/beneficials rather than planting say all the tomatoes in one place, would like to get a 2-storey deal going but don't quite know how. Anyone got a good guide?

This is a link to Toby Hemmenways food forest course. One of the free modules has something about interspersing annuals. About minute 7:50 is where you will find what is relevant to your question but the whole thing is worth watching IMO.

http://organiclifeguru.com/course/food-forest-design-care-for-cites-and-suburbs/

I don't think you'd have any problems not rotating stuff over 4 years if you are doing mixed beds, but I'm no expert.

Miles: Thanks for the welcome! I am indeed thinking of cultivating some edible weeds. A couple of amaranths (is that really pigweed?!), mustards, claytonia, purslane, and of course comfrey (though not edible that I know of). Enjoyed the discussion on that thread. I like a spicy salad, but I mostly want mild yet super-nutritious greens for juicing, especially through the green-hostile months of November through May. So diverse varieties of kale, spinach, chard, leaf beet, parsley for a bit of spice, and I'll probably try a bunch of Asian greens I've never heard of and see how they taste and how they juice up. I'll just suppose that if they're dark green, they're very nutritious for lack of any particular nutrition data. Anyone who's ever juiced Asian greens I'd love to hear from you!

I have a question about this plant called "plantain" -- in my world that is a big tropical frying banana and I have no hope of growing it. Which I'm sure it is, but I'm equally sure that on that thread they were talking about something else! If it's nutritious and it tastes good, I'll put some in! Any info?

Hester: Thanks so much for your post! There was indeed, wailing, gnashing of teeth, rending of garments and the whole lot when I read the regulations and the (expletive deleted) four-year rule. Four years is not a proper timeframe to think of stewardship of the land (I'm sure I won't find too many to disagree with me on this site!). But it's what I have, and otherwise my rural tendencies would be relegated to the balcony.

I really chuckled at your description of the jaundiced neighbours, eyeing my "weird" project. You must live in a small town too! Yes indeed. I hope they are more open than that as I've been told the "association" of plot-holders will have to approve my radical plans at our first meeting next Thursday! Yes, everyone is being encouraged to just dig, turn and transplant, fairly much as their (great-)grandparents did, and if they're really ambitious, put in a shovelful of compost around each tomato plant, and I'm sure that's what most people will do. However that prospect bores me to tears.

I will definitely have a couple of varieties of fennel, and I may try an artichoke bush too as you say. Perennials do make like easier, don't they? Rhubarb, maybe (childhood traumas to keep in mind). Strawberries are something I'm really interested in and know little to nothing about, except that slugs, endemic here, love them! But you mention "runners" and I wonder if there might not be some that it's possible to trellis? That would be a dream come true but I won't get too excited just yet.

Have you got a good introduction to planting in guilds that you like? I can't really do the top tree layer, but hopefully I could manage the rest. I'm eager to learn, hopefully before I plant everything for summer! I like your idea of integrating flowers and plan to do that too!

Regarding the hard pan soil: Hmmm.... do you know Charles Dowding at all? (dot co dot uk) I'm so naturally lazy and his approach seems so simple, and he has a fabulous looking garden. He doesn't really speak about breaking down degraded, hard pan soil specifically, but I so desperately want to believe in his system, partly of course to save my back, but it also goes with the Ruth Stout spirit in me. Maybe it's possible to smother and melt the hard pan over time, and pierce it with the taproots of ambitious plants, rather than going in like a human tractor. I would love to know if a video or two of his moves you at all. Of course, if I'm just deluding myself, better to know now and avoid catastrophe.

Rus: Hey thanks! I followed the link and it is indeed a great video, especially for a newbie like me, but it goes only up to minute 6:58! So I am wondering what is the secret contained in minute 7:50?! Or maybe the link was wrong?

In other news, someone told me a trick for August: Take a big (1.5 liter/quart) plastic water bottle (I will try not to shudder at the prospect of plastic in my garden), loosen the cap a bit, and prick the bottom with a pin. Set by a plant that needs water while you're gone. Seems brilliant to me! Any other good ideas appreciated.

Would still love to know about pine needle mulch (or other mulches) and slugs, and also ways to break down the straw and hay layers of my beds quickly into nutrients for my lovely plants.

Thanks and nice to meet you all!

Dave

As far as slugs not liking pine needles goes... the paths on my allotment are made mostly of chipped Christmas trees. I suspect the slugs have no problems at all crossing them, judging by the speed at which they found and destroyed the brussels sprout plants I put out last weekend! I have recently discovered a slug repellent which is like clay granules, it is REALLY sticky when it gets wet, this seems to have worked with the seedlings at home so I'm hopeful...

If there are loads of rocks, can you use those to edge your beds?

I think if you are trying to convince people of something new, you have to do it a bit at a time. If I was on that site, I might start by doing things more or less how the others are, but gradually introduce new concepts. I know you are thinking like you only have four years to get a permaculture plot, but then you are going to have to give it up to someone else and start anew anyway. The person who gets your plot, they are maybe going to think "hey, this system looks like it might be useful" and they MIGHT carry on with it, and the idea might spread, but it is going to be slow. And then the next plot you get won't have that hard pan, hopefully, even if it's been dealt with by digging. I had visions of maybe breaking it up with a crowbar before you spread the mulch.

When I said strawberry runners, I meant the little plantlets that come off the main plant, on long stalks. These you can pot up and take with you to start your crop in the new plot.

I bought a horseradish plant today and thought of you... deep roots... though it wouldn't make very nice juice! Maybe you need to think not so much "what do I want to get from this plot" as "what does this plot want to give me?"

Dowding looks to have have a lot to say about growing salads all year round using his no dig methods (he's got at least one book on the subject) although he is dependent on a greenhouse. However, there may be some plants that you could overwinter using cloches if they're allowed.

In terms of slug control I assume that you won't be allowed to keep chickens or ducks or allowed to install a pond for frogs? One thing that appears to have worked for us for controlling our resident slug population was the use of nematode worms - you buy them, dissolve them in your watering can and just water your plants/soil with the solution.

The sacking may work to make your raised beds I guess although I'd probably choose to have no borders on my beds - less work, less habitat for slugs - unless your plot is sloped in which case some form of soil retention might be necessary. If you do want to use the sacks, do you have enough stones to fill them? Just a though.

Hi Sam, sorry, I missed your reply earlier!

I would love to hear more about your slug-eating nematodes... Where can i get some of those?!

Re the sacking for the sides, yes my plot has a bit of a slope to it and I'm planning on raising my beds about 18", so I think I'll need something. I'm not planning to fill them though at the moment, just use the flattened double thickness of the two sides of the sack as my border and some sturdy bamboo stakes, driven 30cm/12" into the ground, perhaps 3 to a meter/one per foot to hold it all up. I hope this should get me through a couple of years of winter storms with the odd bit of torrential rain.

Oh yes, and you're right... No chickens, ducks or ponds.

Please, please, please, tell me more about the nematodes! I've been worried about straw mulch making an overly happy home for slugs, but if I water the mulch with slug-busting nematodes... Then I'm home free. Maybe.

So you are making a silt fence with coffee bags as a border, that should be awesome for two years but may start to collapse by year three and four. Seems about perfect considering. I don't know how high they can go, 18" is pushing it. I don't think you want to move enough soil to fill them all that full, anyway. You are talking truckloads. Literally a ton per meter of bed. I would be selective in where my beds were that deep.

Dave Forrest wrote:Hi Sam, sorry, I missed your reply earlier!

I would love to hear more about your slug-eating nematodes... Where can i get some of those?!

The product that we've bought on the past is called 'Nemaslug' if I remember correctly. It seemed quite expensive at the time I recall but it could well have done the job. There's not much more I can say really!!

Dave,
I know what I would do. Just buy a huge round bale of old hay delivered. Then unroll it on your plot. Your done. ready to plant. I generally prefer a weed barrier, but I have done it both ways.

When it comes to amendments like compost, just amend the holes your place you transplants in.