4-Step Crop Rotation Plan

The simplest system is a four-succession plan.  It is easy to remember and very practical.  Just memorize the short mantra Leaf-Fruit-Root-Legume. 

Gardeners who use this system are following the advice of market gardener Cynthia Hizer, whose article on the subject was published in Kitchen Gardener Magazine, December 1996 issue.

Her original system plans for starting with a major application of manure, compost, and mineral amendments, after which the garden is divided into four equal sections.  This is followed by a four year planting succession that takes into account the major nutrient needs of each group; the major nutrients being nitrogen, phosphorus, and potassium (N-P-K).  Basically, the groups are planted in order of their nitrogen use.

 – Leafy vegetables have a high requirement for nitrogen (N).  They use it to form their stems and leaves, which are the parts of these vegetables that we eat.  Nitrogen is also the most soluble of the major nutrients.  Any excess nitrogen not used by the plants will be washed out of the soil and into the watershed.

Fruit – If the portion of the plant we will eat is the result of a flower being pollinated, it is considered a “fruit”.  They have a higher requirement of phosphorus (P).  Phosphorous helps the plant set blooms and then develop the fruits.  In fact, if these plants receive too much nitrogen, they will produce excess leafy growth at the expense of bloom and fruit production.  This is a common problem with tomatoes if they are over fertilized with high nitrogen fertilizers.

Root – Root crops use even less nitrogen than fruit crops and are heavy users of potassium (K). The original Leaf-Fruit-Root-Legume rotation strategy plans for them to fall into the line of succession when the majority of the nitrogen has been used first by the leafy vegetables and then by the fruit producers.  Potassium also takes a little longer to become available in the soil, so the timing should work out in theory.

Legume – Legumes are the nitrogen fixers.  They are capable of pulling available nitrogen from the air and storing it (fixing) in nodules on their roots.  When the plants roots decay, they release the stored nitrogen into the soil where it will be available for the next crop – the leafy vegetables again.

Our observations & suggestions

Anyone who takes a little time to think about this rotation succession will pick up on one weakness.  The entire garden plot is heavily manured (high nitrogen source) to begin with, but each of the four sections is planted with a different group, each of which has differing nitrogen needs.  It’s not like the fruit, root and legume crops can just ignore the nitrogen in the soil that first year.

The original plan does take this issue into account at the end of the fourth year.  By this time Cynthia knows which plot will get the nitrogen hungry leafy vegetables at the start of the fifth year, and only that plot, one quarter of the garden, will be heavily manured.

Why not take this into account from the start?  The soil in the entire garden could be prepared with a heavy application of compost and an adequate application of balanced, slow release, organic fertilizer.  Once the garden was divided into its four plots, each plot could be additionally amended with the required amount of specific major nutrient.   The ‘leaf’ plot would get more frequent applications of nitrogen fertilizer if indicated by plant growth, the ‘fruit’ plot would get an additional dose of phosphorous, the ‘root’ plot some additional potassium, and the ‘legume’ plot would be left to do its job of fixing additional nitrogen as it produced its crop of peas or beans.

This might be overkill.  I am sure that the original plan works just fine.  But there is another factor that Gulf Coast gardeners need to take into account.  We don’t have the luxury, or the restriction, of a garden plot or row that will produce only one crop each year.  We might have two, three, even four rotations in the same year.

We can make this simple four-part rotation system work for us; we just have to adjust for our year-round growing schedule.

As long as you remember that Fruit will follow Leaf, Root will follow Fruit, Legume will follow Root, and Leaf will followLegume, you can grow all year long and never have to worry that any one group will occupy the same space within that year.  You will keep your need for supplemental fertilizer to a minimum, you will prevent depletion of nutrients, you will starve out pathogens and confuse pests, and you will grow your soil with the addition of compost between crops.  This meets all of the goals of crop rotation.

Finessing the Plan

If you want to take this system one small step further, you could add three more options.  They don’t have to be used in succession, you can just drop them in as suits your fancy.  Those extra options are Cover Crop, Flowers, and Fallow.

Cover cropping is a soil building technique used by many vegetable gardeners, even on a market scale.  It is usually done at the end of the season, but it can be done any time the season is right for the chosen cover crop.

Flowers can be a hugely beneficial part of your succession.  They provide beauty, attract pollinators and beneficial insects, and can truly break the pest and pathogen cycle.

Allowing a plot or row to lay fallow just means that you will give it a season of complete rest.  If you want a plot or row to lay fallow, harvest the last crop, apply 2” of compost, water it deeply, then apply 2” – 3” of organic mulch.  Tree leaves are a good option.  They will cover and protect the soil and encourage earthworms and beneficial microbes.  The soil will rest and heal.  When you are ready to plant it again, amend it appropriately for the crop it will carry.  You can leave or remove the mulch, depending on what you want to plant.