Crop rotationWritten by GavinHair-tearing fun – make it as simple or as complex as you wish; but do rotate your crops. Whether you use a spreadsheet, or paper and pencil, work out a workable plan for your plot. Why?Unlike most gardens, an allotment usually has relatively large "blocks" of crops – which can cause two problems. Growing the same vegetable in the same place, year after year, creates an ideal environment in which
Put the two together, and you have a recipe for epidemics striking down ever more sickly plants! At its simplest, all you need to do is keep the crops moving. Leave at least a year, or better a 2/3 years gap, before a crop returns to the same bed. Working it outBeing a bit more systematic, you can manipulate your crops so that they help each other out. As most vegetables in a single botanical family are vulnerable to similar pests, you need to plan using plant families, not individual crops; start with the families, and green manures should fit in fairly easily too. An allotment rotation will probably include the SolanumsPotatoes, tomatoes, peppers, and aubergines must be rotated, as they are highly susceptible to soil-borne infections and pests damage; they should not return to the same bed for three years, better still four or five. BrassicaBroccoli and calabrese, brussels sprouts, cabbage, cauliflower, kale, kohl rabi, swede, turnips, and rocket; also includes mustard and radishes – as crops or green manures must be rotated, as for the solanums. Umbelliferscarrots, parsnip, celery and a number of herbs are keen on rotation, as carrot fly overwinters in the soil. AlliumsChives, garlic, leeks, onions, and shallots are also keen on rotation to avoid encouraging white rot on your plot; if you already have white rot, the family must rotate, with a gap of 8 years. LegumesBroad beans, French beans, runner beans and peas; also includes green manure crops such as alfalfa, field beans, clovers, fenugreek, lupins, tares, trefoil are generally not that fussy; worth humouring with rotation more to keep things easy! Many an older gardener grows his runner beans in a permanent, very rich bed. The second group of crops, bless their cotton socks, are just eager to please and they can go anywhere in your plot, at any time in your rotation plan. BeetBeetroot, leaf beet, spinach, perpetual spinach) Asters (the daisy family)Lettuce, salsify and scorzonera CucurbitsCucumber, marrow and courgette, pumpkin and squash OthersSweetcorn; also green manures such as buckwheat, phacelia, rye and ryegrass. If you are planning a new plot, you will need to allow space for a third group, “permanent” beds (actually beds with very long rotation needs) – strawberries (2-3 years), rhubarb (4-5 years), raspberries (10 years), asparagus (15-20 years), and then the herbs, comfrey, and fruit bushes. Next step? - Which family helps which?
Fit the permutations together, and you’ll get a 5 year sequence like this – each year, a bed “takes one step to the right”. Include “winter treatments”
Reality time – tain’t a strait-jacket!
A few examples I’ve used, or seen friends use – adaptations to fit space available (and what you want to eat!). "Traditional" three year rotation – but you don’t want potatoes 1.Brassicas Four-year rotation I’ve used in the past 1.Potatoes Four year rotation on a plot with white rot (making onions difficult) 1.Potatoes followed by leeks Four year rotation, where you can let some land lie fallow every fourth year 1.Potatoes Gavin has kindly allowed Downsizer.net to publish this article; he has a range of other very handy guides on all aspects of vegetable growing on his allotment diary site at http://www.keirg.freeserve.co.uk/diary/indextec.htm If you'd like to ask any questions do visit the Grow Your Own forum |