Raspberry rhizome barrier

Hey so I'm dreaming about a raspberry patch
(see here for my dreams of combining it with mushrooms on stumps: https://permies.com/t/162229/rid-elms-grow-mushrooms#1271765. I'll happily accept advice on this plan as well!)
Because we're on an urban spot with limited good sun, and because the spot I'm thinking about is going to be right next to the lush annual veg beds, I know I'll need some kind of barrier to keep these puppies from taking over.
Anyone have experience with rhizome barriers for raspberries? I know there are several products on the market. Are they any good? Any cheaper diy versions that work?
Or alternatively, any varieties that spread less agressively? (I'm zone 4, so needs to be winter hardy).

I need some inspiration on this too! I'm in a similar constrained space and am wanting to establish some new raspberry beds and section them to keep the different varieties apart from each other as well as contained. A good rhizome barrier is definitely important with raspberries! My current ones have traveled three feet under a wood chip path and then pushed up through a foot of raised bed for a fun surprise.

For a free and simple temporary solution to keep my current patch from invading the neighboring strawberries (and vice versa), I buried a corrugated plastic yard sign (think the type used for political campaigns) a couple of feet into the ground. It has worked pretty well, but I imagine it would be hard to turn it into an impenetrable barrier around the whole perimeter of the bed.

My other piece of advice is to plan for a T-trellis or some other containment method. Some of the fruiting canes get real long and if not contained will happily flop over onto your veggies, or onto you as you try to harvest the veggies.

"The Borg won't stay on Deck 16."    -Picard

Kidding, I love my raspberries. But they are rambunctious. My solution is to put them far, far away from anything and let them spread, chopping as needed. This is their natural behaviour as they look for nutrients. But I have acres of space to play with.

Some gardeners dig a trench at least 12" deep and chop the runners, but a trench takes space and must be maintained. A heavy plastic barrier (think 8 mil) would probably be effective.

For those who prefer to avoid plastic in the garden, I wonder if overlapping 12" ceramic tiles would be deep enough. I've read that the runners tend to be shallower than the roots of the mature plant. Tile can be had very cheap/free if you know where to look.

I tend to just mow anything that is outside the area I want my raspberries or blackberries. I get shoots, but it is not a big deal.

I wonder if a raised bed would help? Would the rhizome hit the edge and not know to go down first? That is just a though. I have never done raspberries in a raised bed.

Helpful thoughts, all -- keep 'em coming.
While we're at it, anyone have any favorite cohorts for raspberry? Or are they too aggressive to be buddies and they just need their own space?

One of my raspberry beds has asparagus growing in it. They seem to tolerate each other. I don't know enough about asparagus to say if it's thriving or not.

Douglas Alpenstock wrote:For those who prefer to avoid plastic in the garden, I wonder if overlapping 12" ceramic tiles would be deep enough. I've read that the runners tend to be shallower than the roots of the mature plant. Tile can be had very cheap/free if you know where to look.

I bet this would work well - maybe not 100% effective but well enough to keep it low-maintenance. I don't know where to look, though. Where should I look?!

Bethany Ringdal wrote:While we're at it, anyone have any favorite cohorts for raspberry? Or are they too aggressive to be buddies and they just need their own space?

I believe I read somewhere that Eric Toensmeier was growing hog peanuts with raspberries. Not so much to harvest the hog peanuts, but because they were nitrogen fixers and seemed happy living in the undergrowth of the canes. I haven't been able to get my hands on any hog peanuts, so I haven't tried it out.

What about the roll up plastic sleds?(kids,  wild game and chore versions)  They come in 3 ft to 6 ft lengths and widths from 2 ft to 3 ft.  At the end of the season I saw 2 packs of them for $10.  If you split them down the middle that would have given 15" barrier in 5 foot sections so ignoring the needed over lap 20 feet of barrier for $10.  Buried the sun shouldn't get to anything but the edge and a board laid on top with a few nails thru it to keep it in places should keep the sun off that edge.

As for the tiles suggestion above good idea.  If you added a layer of heavy poly to help hide the joints and maybe a layer of the long life weed blocker fabric.  Or maybe 2 layers of tile with the joints staggered and a layer of poly between them.  Maybe used greenhouse plastic as the poly?

Ooh, the sleds are a great idea. I love finding things to repurpose that minimize cost and labor!

When we were in Papua New Guinea we had a tyre garden and a raspberry self seeded.  A tyre kept it well contained.  A friend of ours grew  trail and cane berries in raised (hilled) beds.  when the new growth came up outside of the bed, they used a straight edge spade to cut the roots about 150 mm (6") in from the border and then pulled them out and replanted back in the bed to reinvigorate and expand the beds. In the wild the trail berries grow out from the centre and form a bramble that can be walked around to harvest the berries. The berries need to be contained manually, no matter the barrier used.  Large brambles can be used as hedgerows and trimmed annually but if left uncontrolled can take over native bush land or pastures.  

What would you all think about aluminum flashing? And does anyone know more about building materials than I do? What kind of flashing would be best for this?
There's something called "aluminum roll valley" at hardware stores that's pretty cheap for a 50 foot roll, 20 inches thick:
https://www.menards.com/main/building-materials/roofing/roof-flashing/50-aluminum-roll-valley/999-50-20/p-1444424180106.htm
They say it's .011 inches thick.
Do you think this would do it? Or do I need something thicker?

Here's someone's advice on how to install it...
https://gardening.stackexchange.com/questions/51191/root-barrier-suitable-for-organic-vegetable-garden
I'm not totally clear on what they're doing with the spikes though...

I think aluminum flashing would work very well, although there's  a lot of embodied energy. Galvanized steel would be less desireable (unless you get a bunch for free) as some have raised concerns about the zinc left behind.

The spikes they installed were to prevent frost heave, which tends to cause buried objects to move upward over time. Frankly, I think it's overkill for an application like this. Bury it a bit deeper right away and I think it's unlikely to be a problem IMO.

Aluminium is highly reactive and is not a good thing to use in the garden.  There are suggested links to aluminium with dementia. https://scitechdaily.com/alzheimers-disease-linked-to-exposure-to-aluminum/ It reacts to salt and is easily corroded by acidic soil. There are manufactured boarders using recycled plastics.  I have just completed a 160 M driveway using a recycled plastic called geohex.  Using recycled products keeps it out of land fill.  It is a way that we can help the environment after others have already used new plastic products.  The other thing to use is hardwood sidings (the first side cut from milled timber.  Depending on the tiles, the glazes may have aluminium and other metals mixed in with the silica.  Easiest way to grow canes and trailing berries is to just manage the rootstock that attempts to escape.

I can't speak to the issue of aluminum in acidic soils. It's worth looking into.

In my soil, which tends toward basic (alkaline) I have found pieces of aluminum flashing that I suspect were buried for 10 years of more with no degradation at all. They did have a natural oxide coating from weathering in the air.

Aluminium has an affinity with oxygen so the surface of aluminium is coated with aluminium oxide.  Aluminium oxide is reactive to both acids and bases that break it down into aluminium salts and bases such as sulphate and hydroxide compounds.  Aluminium has a huge number of uses in industry and life in general, so is good for a lot of things.  For me, the question is: "do I want it in my diet?" As for uses, many a partner would love a huge chunk of  aluminium oxide in a ring on their finger.  Rubies and sapphires are aluminium oxide  (Al203) but in a lesser quality is corundum which is used to make sand paper.    Finding aluminium is the ground is probably due to the fact that is persistent in soil for 200  - 500 years according to research where as iron/ steel takes about 50 years to become iron compounds and bound up in ground water as iron oxides and sulphates. But to the question at hand - I would not use metal, particularly aluminium or copper, to edge a garden that I was going to eat any produce from.

Matt McSpadden wrote:

I wonder if a raised bed would help? Would the rhizome hit the edge and not know to go down first? That is just a though. I have never done raspberries in a raised bed.

In my experience this really does work.  I have a sloping area which was my fruit garden.  It started off neatly terraced.  I had a couple beds planted with raspberries, all neatly set up with posts to train wires to (never used btw!)  One of the beds had raised edges on three sides: a short stone wall one one long side, and scaff boards on two other sides.  The other bed was just gently sloping with no edging.  The raspberries in the unedged bed have spread quite freely and I now refer to the whole area as a fruit jungle now!  The raspberries in the edged bed have spread from the unedged side, but not two of the edged sides.  They have spread from one long side which had a shallower step.  I think it does need to be a sharp edge, as raspberries would move down a slope quite happily.

It's a bit difficult now to tell which raspberries are which and it may be different in different soil climate conditions.  But a step of 15inches or so I believe  is worth a try.  A barrier to that sort of depth, whether wood or another durable material should also be effective since they do tend to be quite shallow rooted.

My neighbors had a very high raised bed (probably 3 feet at least?) with a stone wall, with raspberries planted at the foot of it - and raspberries came up INSIDE the bed! That means those rhizomes traveled through several feet of dirt - remarkable. They only had to travel up though - I have my doubts if they could make a similar journey down and then up again.

I count on my raspberries spreading, its one if the things I like most about them.
But I do have one in a 55 gallon barrel,  which it seems to suit it very well, as its producing fruit after a single winter in the ground.
55 gallon plastic barrels are cheap and long lasting.
I have water reservoirs in the bottom of mine, but there's a great thread on using chunks of wood instead.

Has anyone tried to bind in the Raspberry with:

Comfrey Bocking 14 - 4 - 7
Garlic / Garlic chives **
Rhubarb **
Plantain
Rhubarb
Iris
Mint
Burdock
Sorrel
Turkish Rocket
Yarrow
Vetiver Grass
Muscari Bulbs
Periwinkle
Vinca Minor
Oxalis (South)
Oca
Mashua (vining nasturtiums)
Maximilian Sunflower
Goldenrod
Sweet Cicely,
Giant Perennial Sunflower (Helianthus Giganteus) animal feed
Jerusalem Artichokes
Elderberry
Horseradish
?

Any luck?

Douglas Alpenstock wrote:For those who prefer to avoid plastic in the garden, I wonder if overlapping 12" ceramic tiles would be deep enough. I've read that the runners tend to be shallower than the roots of the mature plant. Tile can be had very cheap/free if you know where to look.

Douglas, this comment stuck in my head because ceramic tiles seemed to have the ideal properties for this sort of application, plus I love taking stuff out of the waste stream. It took me a little while to find a suitable quantity, but eventually I nabbed two different sets of leftover tile being given away, one of 12x12 and one of 12x24 tiles (even better).

I dug a trench about 8" deep around the border of the new raspberry bed so the tiles would stick up a little bit—I want this bed to be slightly raised but keep most of the tile under the ground for stability and rhizome protection. I laid the tiles in a simple running bond, and tamped down the soil around them to try to keep them in place. It took a little bit of fussing to get all the tiles straight, level, and tight against each other, but it wasn't a terribly hard installation. My greatest concern was that the bed would suffer from frost heave, that would introduce gaps between the two layers of tiles, and then rhizomes would sneak out the gaps. The bed is on its third winter now and is still looking great, so hopefully it's going to stay like this. I'll probably give it another year or two before I declare success on rhizome containment, but we had some established plants this past summer and nothing got out!