What plants are complementary to these plants in a crop rotation?

Question

I would like to know what vegetables would work well in a garden with the following history:

• Season 1: Tomatoes (various varieties, (vv)), eggplants, peppers (vv), basil, marigold, asparagus (did not survive)
• Season 2: Corn, squash (buttercup and sunburst), pole beans, morning glory
• Planned Season 3: Unsure what to plant here, thinking of root vegetables: potatoes, radishes, carrots, and more beans and marigold

I am also open to suggestions for variations on seasons 1 and 2 as I have other vegetable patches at various states in the above cycle. Suggestions for a rotation of longer than 3 seasons are also welcome.

Answer 1

Root vegetables are a good choice following the squash; root veg (except for potatoes) have a hard time competing with weeds, and squash tends to help keep down weeds in the following season. Squash are heavy feeders, and you generally don't want to fertilize much ahead of roots like carrots, so they do ok on the leftovers from whatever you fed the previous squash crop. (I.e. manure in the fall before you plant squash, then don't manure the following fall and plant carrots in the spring.)

If you wanted to make a longer rotation, you could put more years between having tomatoes and potatoes in the same place.

You haven't mentioned any salad crops: lettuce, chard, spinach, kale, beetroot (to eat leaves and/or roots). As @winwaed mentions, you could also consider broccoli and cabbages, as well as brussels sprouts. If you wanted to insert a year of cole crops, they would be a good fit between the tomatoes and the corn/beans.

An excellent resource for these kind of rotation considerations is Elliot Coleman's "The New Organic Grower". That book targets a larger scale: market gardeners / small farmers, but it's packed with good advice.

Answer 2

I would definitely keep with the beans (and any other legumes you might find). These will help to add nitrogen to the soil. Corn/etc will tend to take nitrogen from the soil (they're often grown together in modern horticultural or pre-European agricultural settings, because of this).

You're in Ontario so more of a temperate climate: You've probably found this already, but you want the cooler tomato and pepper varieties.

How about some broccoli, cabbages, lettuces, spinach?