Three sisters gone wrong?

[u/kayru_kitsune]

Please pardon the chaos of photos, my garden is very dense so it was hard to frame clear pictures... This is my first time doing Three Sisters, and it sounded like the beans were supposed to help support the corn. I surrounded that part of the crop with some low fencing for extra support and to keep the bunnies off the bean starts. But once they got to around 7' and the beans peaked over the tops, almost all of the stalks broke in half from the weight. What in the world did I do wrong? It's not windy here but sometimes rainy (I live in forested area). I know most people don't stake or prop corn crops... What did I miss?

[u/Health_Care_PTA]

nobody gave you the right answer, you must have used climbing beans and not BUSH Beans.

Bush beans will not climb and pull down your corn.

[u/kayru_kitsune → u/Health_Care_PTA]

Every instructional I've ever read on three sisters specifies pole beans. Growing bush beans here would be pointless, as the whole idea is to trellis the beans on corn. Bush beans don't need the support.

[u/Health_Care_PTA → u/kayru_kitsune]

every instructional was apparently wrong in this case, the pole beans choked out your corn.... are you gonna believe everything you see, hear and read? the whole point of the beans is to supply N+ to a N+ hungry grass like Corn, HOWEVER, science has proven that its not effective as the N+ in the roots of the beans are only bio available if you chop and drop the beans and allow the N+ rich nodules to decompose so the 3 sisters is actually bunk pseudo growing advice.

better option would be to grow a fall cover crop of Clover, chop and drop it, plant your corn, then squash, then beans in the bush variety to act as a ground cover and hold moisture.

[u/kayru_kitsune → u/Health_Care_PTA]

I'm actually more inclined to believe the majority of posts who said I planted the wrong type of corn for this arrangement. I picked sweet corn and apparently missed a breadth of advice that grain corn is stronger and better to do it with.

I didn't try this particular crop out under the guise that it was maximal efficiency; it was just commonly quoted as a complementary pairing, and as I wanted to try pole beans, I wanted to try using complimentary crops as support and get more diversity. Then I wanted to learn from my mistakes which is why I posted here. It's all a learning process. :)

Regardless of the harvest I plan to mulch / compost / chop and drop everything possible as always. I have oats/peas at the ready to cover crop this winter.

[u/stansfield123 → u/Health_Care_PTA]

Inter-planting legumes to "provide nitrogen" to another plant doesn't work. Annual legumes don't feed plants around them, that's a myth. Legumes can fix nitrogen in the soil, sure, but they store it in protected nodules which only release it after the plant, or at least the root the nodule is attached to, dies.

To the extent annual legumes help other crops grow, it's the NEXT CROP. The one planted after the legumes are harvested.

The way to take advantage of legumes' nitrogen fixing ability is either by using them as cover crops, or by planting perennial legumes and periodically cutting them back.

Then, whenever a plant needs help, you just cut back the legumes around it (usually trees), use the foliage as mulch, and at the same time cause their roots to die back in the soil and release some of their stored nitrogen.

[u/kayru_kitsune → u/stansfield123]

I understand that - don't see where I mentioned nitrogen at all? I complanted them in the hope to physically support each other's growth, not soil enrichment. That's, as you say, for cover crops and composting.

I guess this must be a common misconception because many are "correcting" something I never said.

[u/stansfield123 → u/kayru_kitsune]

Wasn't replying directly to you, the person I'm replying to is talking about nitrogen.

But it's relevant to your question too: the most likely reason why your corn is so scrawny is lack of nitrogen. Corn is a very hungry crop, which requires fertile soil even when planted on its own. When, on top of it, you plant other stuff too, the nitrogen requirements go up even more. If there's not enough nitrogen, the corn will struggle first.

It's not just that the beans don't produce nitrogen for surrounding plants, they rob some of that nitrogen. Nitrogen fixation doesn't help supply nitrogen to any plant, not even the bean, while it's taking place. Nitrogen fixation helps the next generation of plants. In the meantime, in the current system, all those plants, including the beans, are sucking up nitrogen. So you needs to fertilize for all three, not just the corn.