I'd agree, the issues are more watering and sun requirements, growth rate, and harvest time. For example I plant my peas in April, harvest them in late June when it starts to get hot, which is the time I plant green beans. I'll plant garlic in September, then next April slip in fava beans to grow up a trellis behind them, they seem to decline about the time the garlic is ready to pull.

Companion planting is one way of planting that time has indicated aids in the growth of plants, some are the result of growing conditions. Peas, generally, grow in cooler weather than onions although there is some evidence that alliums (onions) have an allelopathic (growth suppressing) tendency with legumes. Some companion planting involves what may attract insects, both beneficial and pest types.

http://www.companionplanting.net/ListofCompanionPlants.html

kimmq is kimmsr

I plant stuff wherever. Never had an issue with various plant families not getting along with their neighbors. I just make sure that plants don't shade or crowd out each other.

Rodney

Many people do and have and without realizing they have created problems that could easily have been avoided with just a little study.

Research has shown there is validity to the concept as this article from Cornell indicates.

http://www.gardening.cornell.edu/factsheets/ecogardening/complant.html

When I plant sweet peppers crowded in with fava beans, the peppers grow big and they do it quickly. People say there's no reason for this, but it does work. At least it works here. I don't know the real reason for this, but am happy to call it "companion planting".

Have you tried the favas with other crops? Or have you tried the peppers with other companions? Do you have any evidence that some mechanism is at work between the two plants? The fact that they do well together doesn't show anything other that they do well together. Correlation is not causation.

It seems logical that peppers would do well planted among favas. Fava beans are a legume. It is a fact that legumes add nitrogen to the soil. It is also a fact that peppers are heavy feeders. Given those two facts, is it not reasonable to conclude anecdotally that Grubby's peppers do well planted with beans because the beans are making nitrogen available to the peppers? Aren't Grubby's good results anecdotal evidence of cause and effect? Do we organic gardeners require the causes for our successes to be scientifically provable? During the 15 years I've been gardening organically, I've been under the impression that what we "know" as organic gardeners is based largely on anecdotal observations of the results of the techniques we use. I thought it was the synthetic chemical gardeners who require scientifically provable facts to support their techniques.

Whilst the leguminous crop is growing it is, of course, fixing nitrogen. However the N stays in the root nodules of the legume and is used by the legume itself. It is not available to surrounding plants until the legume roots decompose in the soil i.e. after the favas or whatever have been harvested. That is why you cut off legume crops leaving the roots in the soil after harvest rather than pulling them out.

While the favas are growing the nitrogen they are fixing is not usable by the peppers. Most of it is used by the favas themselves. So, no, it is not "reasonable to conclude anecdotally that Grubby's peppers do well planted with beans because the beans are making nitrogen available to the peppers" That would be an entirely false conclusion. Legumes and Nitrogen

Good results are not evidence of cause and effect. As I said above correlation is not causation. Serious organic gardeners do indeed need scientific evidence to back up their methods. Research is far more persuasive than anecdote when putting the case for their methods.

I agree nearly entirely, but you can't dismiss anecdotal evidence as worthless. I disagree that anyone needs only scientific research for anything so organically higgly piggly as gardening. You play around. You wing it. You try stuff and when something clicks, you go with it.

I plant pretty much "intensively", to use that catchword. I have peppers that are in thickets of other plants but not swarmed by favas and they do not do as well. I also understand that people do falsely expect legumes to bless the whole garden with free N fertilizer, and that nitrogen fixing plants are very stingy with their N and don't give it up except under pain of death. But it does work. For me. In this climate. Anecdotally!

I don't eat favas. Hannibal Lecter ruined any chance of me ever trying them. They're a manure plant and the ones growing now will never set seed because of the heat (the Autumn ones will).

Also, I've been waiting for years to use "higgly piggly".

Fava beans are pretty good. I eat them raw, outstanding in the garden.

Absolutely - I grow them only to eat. The nitrogen is a byproduct for me.

One of the best companion plants is radishes with young onions.

In 30 days the radishes will be gone & the onions can grow to fill the space the radishes were in. Square Foot Gardening use this kind of space saving companion planting.

I just finished companion-planting peas, favas, onions, and leeks.

There's a lot of confusion over the terminology here. Merely planting one crop next to another isn't companion planting. Intercropping isn't the same as companion planting. Nor is successional sowing. Nor is catch cropping. jolj's example would count as catch cropping. The plants do not have an effect, real or imagined, on each other. intercropping, catch cropping and companion planting

david52- If you believe the companion planting stuff then you shouldn't have planted legumes next to alliums. They supposedly don't get along with each other. :)

Rodney

I think that was david52's point.

And that's why I put the smiley at the end of my comment.

I do not know that you are right, My onions are doing good & I am eating radishes larger then golf ball that are still hot & hard.

If it is not the onion radishes mix then why am I getting large radishes, when all my friends radishes are bolting?

The forgottenone - ha, ha - it's hard to get humour in print, isn't it? Bit of a duh moment for me.

jolj - think of all the other variables before you give credit to the onions. Maybe you're just a better gardener? Correlation does not imply causation. Margarine causes divorce