Is allowing plants to self-seed and crop rotation compatible?

Letting vegetables self seed so that i don't have to do it is an attractive idea. However, I can't understand how it would be compatible with crop rotation. If i leave the same few plants in the same bed, year after year to self seed, wont that cause disease problems?

If I have a diverse polyculture of stuff in those beds, am i still going to have problems with diseases?

How about everything competing with each other? Would the fast growing plants shade out the slow growing plants the way they do with weeds? For instance: if i have mixed lettuces and garlic in the same bed, will the lettuce spring out of the ground and deny the garlic seedlings access to the sun? Would this mean that i need to plant stuff with similar maturity dates and heights? Can i reasonably expect to be able to selectively thin the beds so that the slower growing stuff will access to the sun?

Part of your "problem" is taken care of by the seasonality of the plants themselves. Garlic competes for the sun very well in mid-winter, sending up thin green spikes that punch through everything else that is having slow-going. By the time it is warm enough for the lettuce to start spreading out, the garlic is well above it. In the wild, self-seeding is the ultimate crop rotation as everything competes for both space and time.

Some plants change their shape as the season progresses. We think of lettuce and cabbages as low plants with the profile of a bowling ball, but when it warms up and it's time to flower, they turn into tall, spiky things. It's their way of out-competing the weeds. And when the tall seed stalk dries out, the seeds that they dropped may lay dormant for a few months while something else is having its turn.

I'm still searching for the best mix of different maturity dates and heights to plant so that I can have a constant harvest, thinning out the beds by harvesting what is ready. In fact, I better get out and pull some turnips (fast growers) so that the celeriac (slow grower) can get some more sun.

You never fail to give a simple, direct answer when i can't find it from Google searches. Thanks for taking the time to write all the responses you have written to my posts.

I have garlic, radishes and green onions together now. Perhaps not very wise to plant two root crops together but they have very different maturity times and the garlic, like you said, pops up above the radishes so it isn't having the shading problems that the weeds are (muhahaha). Plants the discourage spider mites are MANDATORY in Taiwan unless you are using heavy pesticides and garlic is the only one i have been able to grow successfully (coriander just doesn't want to cooperate with me). The onions were the roots from the bottom of some store bought stuff my wife got.

I went ahead and tossed a mixture of: carrot, green onion, some big, white radish (maybe daikon, I have no clue what "daikon radish" is in Chinese), two kinds of leafy greens, both of which i think are called "pak choi" in English speaking countries, and some coriander. I tried to do some deep rooting (carrot and radishes) with some fast growing and shallow rooting vegtables (the greens). The corriander and onions are there to discourage pests. I tossed this on the "experiment" side of my little bed. I will be gone in three months so I dont think i would get any benefit from adding any nitrogen accumulators. I hope that a few of these will thrive and a few wont. Hopefully the ones that don't thrive will have some easily diagnosed problems so that I can learn from it and take that experience to Washington.

On that note, what kind of mixes are you having success with? What are you not having success with? I know your "still searching" but I think many of us would appreciate hearing about your progress and adding your experience to our own knowledge.

Let it happen and see what you get then adjust as you go. For example: I have
learned to avoid salad mixes with arugula in them. I like a little of it and ...I get a lot.
It out competes the various lettuces. I still find the odd plant popping up. Just enough.

There are different schools of thought on crop rotation. There is also the transplanting option,
to consider as you have grown free plants that can be easily moved.

Strict adherence to crop rotation is something that developed out of and is far more important in monoculture systems. Those systems tend to deplete key nutrients and to invite pestilence and disease. A polyculture will have many deep rooted perennials which bring up nutrients, annuals and a variety of weeds. When we look to nature, the rotation or succession turnover is not an annual thing. The park that is beside my job site has been a Gary Oak meadow for hundreds of years and is likely to continue for hundreds more.