PLANTING SYSTEMS: SUCCESSION PLANTING, CROP ROTATION, INTERPLANTING & COMPANION PLANTING
All of these systems mimic natural ecology in the garden environment. An abundant year-round harvest of healthy food, the building of vital soil and natural management of plant pests and diseases should be the result. Each system serves a different function, so they compliment well in one garden. Intercropping is recommended for smaller spaces, especially urban situations, whereas Crop Rotation is more suitable for larger garden areas, and especially in the growing of staple crops.
Succession Planting is sowing or planting a crop a little at a time to ensure a continuous supply of vegetables throughout the harvesting season, avoiding both lean and glut times.
Tips:
* Maturity Dates – the shorter the maturity time, the faster the turn around time, so such varieties are best for succession planting eg lettuces can be planted out fortnightly.
* Nutrient Requirements – don’t plant members of the same family in succession. See notes on Crop Rotation, the same principles and crop sequences apply.
* Harvesting Dates – decide which crop cut/plucked before the others and note timing left for following crop to mature in, to check there’s adequate time before going ahead with planting.
* Frost Danger – check when frost times typically happen at either end of the growing season, so as to avoid planting tender crops outside the frost free period.
Non Frost Tolerant Varieties: beans, corn, lettuce, beetroot, summer spinach, melons, cucumber, squash, tomatoes, peppers, eggplant, okra.
Frost Tolerant Varieties: brussel sprouts, kale turnip, sprouting broccili, potatoes, carrots, shallots, parsnips, asparagus, chives, garlic, onions, rhubarb, celery, winter spinach.
Interplanting or Intercropping is the practice of planting more than one crop together either in blocks, rows or spaces. It uses all of the available space in the garden at all times.
Tips:
* Stack in Space - grow the most plants possible in the smallest space available. Those plants that don’t like strong sunlight grow in the shade of their taller neighbours, the plants whose roots mine for the deeper minerals, grow happily next to shallow rooting ones which only need to range near the soil surface.
* Stack in Time – grow plants in succession, when one comes out, another goes in. To be a good ‘intercropper’ its essential to observe the time it takes for each species to mature, and growth stages. Then you can prepare to have other crops ready to take advantage of the niches created. See ‘Succession Cropping’ above.
*Create a Garden Ecosystem – encourage plant diversity. Mix tall, short, perennial, annual, deep & shallow rooted, different flowering times, various colours. Each provides a different habitat and food source for creatures – share your garden with birds, bees, butterflies and other insects! See Companion Planting handout.
* Feed the Soil Well – this is essential with such a quick turnover in vegetables. Compost well at beginning of growing season, mulch each crop that goes in, use natural foliar feed/liquid manure tea fortnightly to nourish crops.
* Trial Various Guilds - find ones most suitable to your conditions, then repeat them. The following are examples of vegetables which work really well with an interplanting approach, as each has its unique properties and occupies a different niche, mutually supporting the others in the guild. Try them out and let them teach you.
- Aztec Triad/Three Sisters: corn, bean, squash/pumpkin (plant corn first)
- cucumbers, sunflowers, okra (plant sunflowers first)
- tomatoes, lettuce, beans
- brassica, leeks, shallots
- silverbeet, celery, parsley
- radishes & carrots in same row, beetroot & kohlrabi in same row.
Catchcropping is a small, quick maturing crop among or alongside main crops which take longer to develop. It is an aspect of interplanting.
Some vegetables most effective for catch-cropping are: lettuce, dwarf bean, cress, mustard, chives, celeriac, radish, turnip, corn salad, early carrots.
Companion Planting is a particular application of interplanting. The companion assists the main crop in several ways eg opening up the soil, supporting growth, improving flavour, protecting it from being attacked by pests because of its fragrance or a substance it exudes.
Is done to:
(a) attract or repel insects (see handout on pest management)
(b) enhance the growth, health and flavour of neighbouring plants eg tomatoes, cabbages, beetroot, carrots, parsley. Some plants release oils and minerals into the soil (eg marigolds, beans, peas, lupins) which enhance the growth of some plants and inhibit others eg potatoes and tomatoes as neighbours inhibit each others growth, sunflowers inhibit most competitors, but are fine with beans growing up them!
Many herbs and flowers make good vegetable companions. See separate chart for these, as well as the column on Companion Planting in the Vegetable Planting Chart.
Crop Rotation is a traditional method used to cleanse, protect and replenish the soil. It is a cycle of growing different crops in the same area.
Do it for:
(a) Soil fertility & nutrient replacement - as the nutrients in the soil are slowly released, each plant uses them at a different rate, and with more demanding plants or ‘heavy feeders’ (eg corn) in a crop rotation, the soil has time to build up its nutrient store again. This prevents ‘soil exhaustion’, otherwise resulting in ‘crop starvation’, reduced yield and as poor food value.
(b) Pest & disease management – disrupts disease life cycles and the build-up of insect populations. These generally depend upon a specific host plant family to live on and reproduce eg cabbage maggot, carrot wireworm, brassica club-root, potato root eelworm/nematode
(c) Weed control – different species germinate at different times of the year, and the variation in crop depth and surface area covered, as well as bed treatments, can prevent weeds from getting a hold.
Tips:
* The longer the time before a crop is reintroduced to the same bed, the better.
* Plant crops with similar nutritional and mineral needs together.
* Do not immediately succeed members of the same plant family with one another (check Vegetable Planting Chart column: Plant Family).
* Include legumes in the cycle to increase nitrogen in the soil.
* Do a minimum rotation of 3 years, maximum 8, usual and recommended: 4.
Typical Cycle within a Year
Spring Autumn Winter Summer
Leaf Root Flower cover crop Fruit
eg cabbage eg beetroot eg lupin eg cucumbers
A Recommended 4-Year Crop Rotation
Plot A Plot B Plot C Plot D
Year 1 Root Crops Potatoes Legumes Leafy Veges *
Year 2 Potatoes Legumes Leafy* Root Crops
Year 3 Legumes Leafy* Root Crops Potatoes
Year 4 Leafy* Root Crops Potatoes Legumes
NB: * Tomatoes, corn, and ‘trailing crops’ - the cucurbit family (eg pumpkins, cucumbers), can also be included with or replace leafy vegetables (eg brassicas) in rotation. Leeks and celery can also be grown in place of potatoes, as they are also ‘earthed up crops’. Quick growing plants (eg lettuces), can be fitted in any gaps.
Organic Additives: to prepare for the next new crop, treat the soil in the following way (and keep rotating this pattern year by year):
Yr 1; Plot (A): Deep dig and lightly feed with compost (no nitrogen)
(B): Very heavily fed (manure but no lime)
(C): Moderate feeding eg compost (no nitrogen)
(D): Lime and feed heavily (manure/compost and blood & bone)
‘Grow It!’ series: Planting Systems
Victory Community Centre, Nelson