Crop Rotations

“Crop rotation” is a basic agricultural practice where each crop is planted in a different location from year to year. Its purpose is to lessen pest and disease buildup and to give each crop fresh ground to grow on each year where a crop in that family has not grown for several years. Depending upon the amount of each crop grown, each block in the rotation is made up of either a single crop or a group of biologically related crops, or in some instances those crops which are managed similarly and are not otherwise related.

One of the difficulties we faced was that our gardens are of all different sizes, and as a result it took some time to develop a rotation plan with roughly equal plots.

Another problem is that for each of the crops we grow the amount is not static from year to year. We are constantly discovering that we should be growing more of one veggie, or less of another. Any change in the amount of space we allot for a veggie needs to be able to fit into one of our rotations. Additionally, for the past 15 years, we have been adding new fields into the mix. We now have eight plots of roughly 17,000 sq.ft. on the old side of the farm, some of the plots made up of several separate gardens. The new side of the farm has four half-acre plots.

These rotation plans involve the abstracted placement of the crops, without any direct connection to what field they will actually be planted in for any particular year. Considerations for developing the rotation successions include what kind of management will we give the crop in Year 1 and how that will affect management of the Year 2 crop, and so forth for each year. For example, tomatoes are mulched heavily and are followed by garlic and onions which are also mulched heavily. This results in a high organic matter soil and low weed population field in Year 3, which is very beneficial for small seeded drops like the Roots & Leaves. Since Roots & Leaves may leave the field weedy, we grow a PVO cover crop in Year 4, which leaves a high organic matter relatively weed free plot for Year 1. So our tomato rotation is very effective at eliminating weeds.

Another trick we use is to move around our two four-year rotation groupings among our eight fields. For example, since the first two years of the tomato rotation is very effective at combating weeds, if we notice one of our fields is getting too weedy, we’ll start the tomato rotation in that field.

Assumptions include that each rotation block is roughly equal in size to every other, because they will eventually have to be assigned to an actual field plot. This has to be reconciled with how much of each crop we want to grow and have a market for.

Notes:

Because of the great diversity of our crops, we have three separate field rotation groups. The Squash rotation is on the new side of the farm, which has four half-acre plots.
Since all the the blocks within each rotation need to be approximately the same size, we often group several similar minor crops together to match the space taken by the major crops.
Sometimes whole rotation blocks are rotated with other rotation blocks of the same size, such as when a field is moved from the Roots & Leaves Rotation into the Tomato Rotation.
We include notes in the rotation blocks below to indicate some of the important considerations determining why that crop is in that position in the rotation.
“Roots & Leaves” is a catch-all grouping for any or all of: Chard, Kale, Celery, Celeriac, Beet Greens, Spinach, Lettuce, Basil, Spicy Greens, Carrots, Parsnips, Bok Choi, Napa, Broccoli, Cabbage. Many of these crops appear in more than one rotation group.
In the Roots & Leaves rotation, we groups several crops together because they are full-season crops; they get planted from late April to late May, and remain in place the entire season: celery*, celeriac*, Brussels sprouts*, parsnips, rutabagas, chard, kale and lupines. Those crops with a * are mulched with young hay.
All of the greenhouse crops are preceded by carrots, lettuce, spicy greens, spinach, radishes, beet greens or summer turnips, which are planted during the winter months.
The greenhouse rotation is somewhat skewed toward the tomato/pepper family since there are so few veggies we have to choose from that benefit from
early and/or late season extension in a greenhouse. We have tried pole beans and bush beans, but were disappointed with their yield potential.
All of our crops, except the perennials, are in a rotation plan. Short-lived perennials, such as the woody culinary herbs, are also rotated as a block every four to five years into a field that was formerly annuals. This helps to deal with the perennials weeds that invade perennial plots over time.
Certain crops come out early and are followed by another crop. Successions within a single rotation year are indicated like this: FirstCrop⇒SecondCrop (that is, FirstCrop is followed by SecondCrop).

ROTATIONS
Name	Year 1	Year 2	Year 3	Year 4
Tomato Rotation ¼ acre ea.	Tomatoes mulched	Garlic (planted late in Year 1), Onions, Shallots all mulched Garlic⇒Broccoli	Roots & Leaves small seeded crops poor competitors	Cukes & Summer Squash vigorous transplants good competitors
Squash Rotation ½ acre ea.	Winter Squash mulched	Potatoes like old Squash mulch	Beans & Peas legumes Peas⇒Spinach	PVO Peas, Vetch, Oats mix
Roots & Leaves ¼ acre ea.	Roots & Leaves succession crops Beet Greens, Lettuce, Spicy Greens, Basil, Dill, Cilantro, Carrots, Scallions	Roots & Leaves full season crops Leeks, Chard, Kale, Parsley, Parsnips, Lupine, Celery, Celeriac	Roots & Leaves succession crops	Cover Crop PVO or Oats⇒BW⇒BW⇒Oats
Greenhouse Crops 2,000 sq. ft. ea.	Carrots⇒Tomatoes	Lettuce, Spicy Greens, Turnips⇒Cucumbers⇒Chard	Beet Greens⇒Cherry Tomatoes	Spinach, Radishes⇒Peppers