We all need friends. Apparently, so do vegetables. Why else could someone write a book about companion planting. My plants have lots of friends- bees, birds, chickens, me- but they also seem to need other plants that are, you know, ... friendly. I have given this considerable thought over the years. I know you think that it is because I have way too much time on my hands, but the truth is I am an intensive gardener. Nay! Make that extreme gardener.
The idea of intensive gardening was developed for people with big needs and small space. It requires deep soil, lots of fertilizer and water, layering of roots and planning for light and air needs of plants. Essentially, you look at your space and plant things together so that different layers of root space use the whole bed without tangling up with each other. And the plants are tied up, staked, or balanced for different heights so that shade loving plants are under taller ones. You need to place the bed in such a way to insure lots of air circulation and water from ground level so that leaves don't get wet and encourage mold. Since you can't get in between the plants to weed and fertilize, you have to fertilize in the watering system and weed as plants are retired. It is the Science of Gardening for the excessive/compulsive personality.
With so many plants in one little space, I suppose they should be friendly with each other, so as to get along well. So, how can you tell if they are making friends and enjoying each other's companionship? It is not like they invite me to the party. I don't even think they notice me at all. It would seem to me that most of my plants get along out of sheer necessity. I have four eight foot by four foot beds that are one foot deep, that is one foot of rich top soil. Each bed has a mass of plants- beans, corn, celery, fennel, ginger, garlic, parsley, tomato, potato, squash, pepper, cucumber, and cilantro. The only unhappy member of the party was the cilantro- which bolted as soon as possible but made wonderful coriander seeds. I am not even sure it was unhappy. It attracted bees, looked beautiful, and made great bunches of seeds.
Generally, I plant seasonal plants together. I don't pay any attention to rows and spacing. Some plants are comfortable when close to another and the others find a way by falling over or choking someone out. I always let a few last season plants go to seed. The flowers attract bees. And in the winter I refurbish the bed with compost, worm castings, and aeration. Winter here is about two weeks in December, so I work fast. During the growing seasons, I work an area where the plant has finished and install a new plant or seed in that space.
Really, when you think about it, the plants have to get along because they have no choice. It's put up or shut up. Lately, it has been very quiet out there.