Staple polyculture idea

I've got this idea for a two-year crop rotation polyculture-based way to grow potatoes, buckwheat and amaranth, along with some other, minor crops. The species I'd like in there are as follows:
-Potato (Solanum tuberosum)
-Buckwheat (Fagopyrum esculentum)
-Grain amaranth (Amaranthus spp)
-Creeping bellflower (Campanula rapunculoides)
-Marsh woundwort (Stachys palustris)
-Aardaker (Lathyrus tuberosus)
Plus maybe an additional nitrogen fixer, like white clover (Trifolium repens).

The core of the system would be potato, buckwheat, amaranth and creeping bellflower. Every patch of the polyculture would alternate between "root years" and "grain years".

The root year starts with planting potatoes into a bed with an established population of creeping bellflower (and possibly other wild-type perennial root vegetables). Mulching is used to suppress the bellflower closest to each potato plant. In the autumn of the root year, the potatoes and the bellflower roots are harvested. Some bellflower roots will remain in the ground as it is nearly impossible to kill creeping bellflower. The ground is lightly mulched.

The grain year starts with pushing aside remaining mulch and sowing buckwheat and amaranth in the soil disturbed by last year's root harvest. Creeping bellflower plants will start popping up. Their leaves are harvested for food so that they don't shade out the buckwheat and amaranth seedlings. Once the buckwheat and amaranth are tall enough to manage, the harvest of bellflower leaves stops, and the bellflower forms a groundcover under the taller grain crops. In the autumn, the grain crops are harvested, and the ground mulched. Repeat.

So, what do you all think? Possible? A terrible idea? Modifications needed? I'm planning to build a couple of small beds for trying it out this summer.

The first experiment has been made: co-growing potatoes with creeping bellflower. The results are decidedly promising. They seem to play nice. In the end I didn't even bother to suppress the bellflower around the potatoes, since the potato plants got up above the main level of the bellflower leaves quite quickly. The harvest of the two potato plants in the tiny test bed didn't seem worse than the average harvest per plant in the rest of the potato beds. There was also a smaller, but tasty, harvest of creeping bellflower roots, even though I replanted the biggest, best-looking roots for next year.

Since it's the first year, the results are somewhat uncertain. For instance, in the event that the bellflower would turn out to be allelopathic, the substances responsible for it might take some time to build up enough in the soil to harm the potatoes. Also, the relative quality of the soil in the test bed compared to the main potato beds is uncertain, and both will hopefully keep improving in coming years. Still, it is a very good start.

I'll call Root Year 1 a success. Next year we'll see how well the bellflower grows with buckwheat. Possibly also quinoa, which will replace amaranth in the plan, since we've tried amaranth for three years now, and it hasn't done much of anything. Quinoa, on the other hand, looks a bit promising. I plan to keep the creeping bellflower confined to the test bed for two more years, in case it plans to start wreaking havoc, before allowing it in any part of the main beds. To be continued...

Looks promising Eino!

Hmm, I like the sound of those bellflower roots - edible and tending to invasive in Scandinavia? They look a fair size. How do they taste? I have some bellflower, but I can't remember which sort, in a rather shady area. The top parts seem to do pretty well and I nibbled a few leaves for salad this year and they were OK. Maybe I'll try transplanting some to a sunnier spot!

Is it worth trying a grain like rye, oats or bere barley? I find I get a reasonable crop of these from a spring sowing. They might shade out other plants though (bere grows in a polyculture happily with silverweed I'm finding!)

I love any plan that involves purposely growing creeping bellflower which seems to be the plant people around me are most crazy about vilifying. I've eaten young leaves and flowers but not roots from it.

This is such a lovely idea.  I bet the results when blooming were very pretty.

That is a great harvest.

The creeping bellflower thing made me laugh, it's one of those plants people dedicate whole summers to eradicating. Curious whether the root harvest ends up being worth it as more than just a bonus to the potato yield.

Nancy Reading wrote:Looks promising Eino!

Hmm, I like the sound of those bellflower roots - edible and tending to invasive in Scandinavia? They look a fair size. How do they taste? I have some bellflower, but I can't remember which sort, in a rather shady area. The top parts seem to do pretty well and I nibbled a few leaves for salad this year and they were OK. Maybe I'll try transplanting some to a sunnier spot!

Is it worth trying a grain like rye, oats or bere barley? I find I get a reasonable crop of these from a spring sowing. They might shade out other plants though (bere grows in a polyculture happily with silverweed I'm finding!)

Yes, the size is good, these aren't the biggest I've seen either. Me and a friend harvested some that were about the size of small-to-average carrots. The taste is a bit bitter, but in a pleasant way, and a bit nutty. The consistency is also really nice, smooth and soft. This harvest was a bit more bitter than last time I ate them, might depend on precise timing of harvest and/or mode of cooking - I think last time they were harvested later in the autumn and boiled longer. My girlfiend says part of the taste reminds her of sunroots, which makes sense since creeping bellflower also stores inulin. That's actually the only downside of it as a crop, people sensitive to inulin might have issues with it. I never got much flatulence from it though, and I do get some from sunroots, so maybe it's a bit milder somehow? Or maybe I never ate enough of it in one go.
One nice thing with the roots is that they are really easy to clean. Just put them in water and rub with your fingers, and all the dirt and small roots come off, leaving a smooth white surface. No brushing required.

That's definitely a thought, growing it with grains! I imagine you might have to sow the grain a bit thinner than usual, though. Creeping bellflower does handle some shade, but I'm not sure it'd like a full-density grain field.

Christopher Weeks wrote:
I love any plan that involves purposely growing creeping bellflower which seems to be the plant people around me are most crazy about vilifying. I've eaten young leaves and flowers but not roots from it.

Yeah, people seem to love to hate it. I don't really understand why. Just because it doesn't require human intervention to thrive? I've never seen any large area completely taken over by it, the way some "weeds" can do, and it's just so useful... I guess some people dislike the idea of something they can't manage to fully control.

Anne Miller wrote:This is such a lovely idea.  I bet the results when blooming were very pretty.

That is a great harvest.

It probably will be beautiful when blooming, but for now I removed (and ate) the flowering stalks before it got to that point. I'd like to be sure it's not going to kill off the other things I want to grow before it starts self-seeding all over the place. But yes, I imagine combined with flowering buckwheat and aardaker, and maybe parsnips and a few more things, it might pass for a flower bed!

I've been trying to find some nutritional information about creeping bellflower roots and finding little. It may be that the starch is mostly inulin as you say - most comments on the flavour say it is sweet like an artichoke. As to invasiveness... I think I was put off trying it because the Ferns say they had trouble growing it in Cornwall due to slugs eating it....Without slugs though...


picture from garden variety life blog

It is growing along cracks in the pavement, which would make it hard to get rid of (or dig up to eat)
Pretty though, and the leaves and flowers also edible as you say.

How do you get on with the Aardaker? I'm finding it a little less than vigorous, although I think I have some survivors. It looks a little too like other small vetch plants to be sure what I've got!

Then our experiences with aardaker are quite similar. Less than vigorous is a good description. I just always assumed it was because my plants grow in a less than perfect place, with somewhat less than good soil... I keep meaning to transplant some to a better place, probably a bed on Garden Hill, but haven't got around to it yet. They have yet to flower (which might be because they don't get full sun such a large part of the day), and never grow very tall. They do seem to survive quite well, though. They've been in the same spot for I think three years, and don't seem like they're about to die out.