I've debated this ever since growing in small boxes. However, I feel that small amounts of interplanted varieties should not be as problematic as the planting of large amounts of the same or similar varieties in the same location repeatedly. In other words, I doubt that 3 tomatoes planted after 3 broccoli that was in the space before, would be affected by a similar disease problem. I have watched the local commercial strawberry growers use the same plots every year to grow their berries. After harvesting in late summer, the fields are covered with a clear plastic to solarize the field, then it is replanted with the same monocrop. I plant snap peas, followed by pole beans in the same location - on the north side of my planter boxes - with stakes to grow on - and it doesn't seem to be detrimental to either the peas or beans. Both, do however, produce their own nitrogen to some extent, which may be a factor. The areas planted are usually pre-treated with fresh home-made compost before planting - and it is constantly being refreshed in these planters. Just my 2 c's. Bejay

This is the organic Gardening thread! Some interesting points have been expressed in the thread. One of the key organic principles is replenishment; of course referring to nutrients and organic matter. The use of cover crops, rotations, intercropping, green manures, recycling refuse and manure to name a few, fill the replenishment options. That certainly does not preclude the organic amendments for deficient nutrients or adjustment of pH. The OP specifically poised the rotation topic. It compels me to ask of those who plant the same plants in the same location, "What do you proclaim to be the cause of pests and disease?" If a plant(s) succumbs to a pest or disease in that location from year to year, do you not think that the origin might be the soil? Rotation is primarily directed at avoidance of direct exposure to pests and disease that exist in the soil. While there is also truth in healthy soil reducing the impact of pests and diseases, moving the host plant to a fresh location reduces the incidence. The continuos presence of the host (as mentioned by Peter) continues the cyles of pests and disease without interruption. By rotating crops you insert a non-host species or one that is antagonistic to that pest or disease (i.e. - marigolds for nematodes). Diversity of planting is also an enhancement, especially for pests and disease. The availability of nutrients is also a factor in the growth rate of the plants; a plant growing too fast or slow suffers stresses which are invitation to pests and diseases. Being in a zone 5 and growing many long season heirlooms I am compelled to start most for transplanting. Timing the starts attempts to have a strong plant able to adapt easily when placed within the suitable growing conditions. Transplants also permit me to properly prepare the beds. For me rotation means having a growing plant or crop in the soil 70-80% of the year. A fall green manure and/or cover crop is part of the plan. Timing of fall sowing may require inter-seeding to permit suitable germination and growth before first frost. Turning under the spring growth prior to transplanting adds nutrients and organic matter which must be given 2-3 weeks for initial decomposition; so not to starve the transplants of nitrogen. Rotation does have a part in the small and medium scale. For my two distance-separated plots totalling nearly 10,000 square feet it is simple to rotate plantings by simply leapfrogging beds. My five year rotation plan shifts each wide (3 feet) bed about 21 feet (including the paths). For nutrient replentishment I strictly limit amendments to compost, composted manure (cattle/horse) and green manure. My soil is tested every three years for comparison. My nutrient management plan is based on improvement versus maintenance. My primary plot is sand which has produced for nearly 40 years. A new plot of silt-loam on a beef farm has been in production for me over five years. My only bad year was 2009 due to very brief summer weather and only about 30% sunny days. I'm sticking to my rotation plan.

are you running a single zone system or valves for multiple zones. in either case I would recommend a pressure regulator for each zone set for about 40 to 45 psi. any higher pressure tends to crack the caps on pop-up heads over time.

Stephynb, In all reality, as blocks come open, you'll do like everyone else... you'll pick up your seed packets and see what "fits" in that spot best. Will carrots or radishes grow quickly, or do you need a square of beans to make up for the ones that aren't producing yet? Oh, or would lettuce be better there because the tomatoes are getting big and the lettuce likes the shade better than the beans like it. You can plan your crop rotation and everything else to your heart's content, but your garden will tell you when it's ready for something else...and that something else may not fit the "plan" you have drawn. I rotate the heavy hitters from year to year. I planted my maters in a different bed this year than last year. I used what I learned last year about the sun patterns on my beds to lay out this year's garden.