Companion Planting

vegetable garden planning companion planting

A monoculture is susceptible to disease and pests.

Companion planting is a system of planting a number of different plants together, so that they benefit by from their close association.  Sometimes in agriculture we may see monoculture, an areas where there is a single crop or plant species.  Whether its a plantation, a field or a garden bed or even a row this makes it easier for disease to spread and pests to invade.

In nature its much more common to see a diversity of plants intermingled and growing together.  The plants thrive more from their association with other plants in a number of possible ways.  Companion planting grows a variety of plants together for some mutual benefit.

Unfortunately there is a lot of myth and misunderstanding about companion planting. Companion planting is often portrayed like a Hollywood romance, an instant attraction followed by happily ever after. A helpful rule to remember is that companion planting will help solve a problem ONLY if that problem exists.  The problems that need solving are dependent upon the local conditions, and so the effectiveness of companion planting will vary as much as the relevant local conditions vary.  The problems of Europe may be no-existent in the US., the pests of North America may be absent from Australia. The soil conditions of one neighbourhood may be completely different to those of the next village. The conditions of shade, competition and previous use may be completely different in one back yard to that next door.

Occasionally plants that benefit each other in one situation may have the opposite effect in another.

Companion Planting and Nutrition

vegetable garden planning companion planting

Companion Planting involves a diversity of plants in one bed

One way that some plants can support others is by providing some nutritional element that is needed.  Most commonly nitrogen fixing plants provide support for root crops and heavy feeders.  Deep rooted plants can absorb a variety of nutrients from deep down in the soil, and make them available to other plants when leaves die back or are added to compost.

Companion Planting and Pests

If a disease or pest is present in the local environment, whether that is country, region or garden bed companion planting may help.  Pests find their target plants in a number of ways the action of the companion plants needs is related to this process.

Pests and diseases in the soil will be affected by plants that releasing a chemical into the soil that kills or repel that pest.  Feeding insects may identify their host plants by scent, in which case a plant that produces a masking odour would be a good solution.  Other insects identify their food by sight, so disguising their shape with plants of a totally different silhouette will confuse the miniature munchers.

Attracting predators that eat your garden pests is another way that companion planting can benefit your veggie patch.  Alternatively luring pest away from your vegetables to an alternative planted as a “trap crop” can be a solution.  I have heard of weeds being used in orchards and vineyards for this purpose.

Companion Planting for other reasons

Other reasons for companion plating are to attract pollinators, create a micro-climate, or even just the convenience of having plants with similar water and nutritional requirements together.  Sometimes plating some crops together can even improve the flavour of crops on your plate.

Allopathy or Competition Between Plants

Some plants actually inhibit the growth of other plants by competing for the same resources, or by creating an incompatible environment such as a growth inhibitor or making the soil too rich for a particular plant.  Inhibiting the invasion of your vegetable plot by weeds and grass is advantageous, but inhibiting the growth of one vegetable by another is something you will want to avoid.

Companion Planting in Practice

Overall multiple plants grown together in the same garden bed can improve yields and crop quality.  Best results are obtained by developing your understanding of companion planting in your plot as your gardening experience grows.  Experimentation and record keeping will build knowledge, and that is one of the roles of this website.

A first step in garden planning

Vegetable Garden Planning

vegetable garden planning

Vegetable garden planning

The first step in any type of garden planning particularly when planning for a vegetable garden is to look at the existing situation and find the best spot for the garden.  There are a number of things to consider when assessing the yard and deciding on the design and location of your new vegetable garden.

  • interference with other backyard activities
  • sunlight and shade
  • water
  • competition from tree roots
  • windbreak
  • protection from pets and wildlife
  • ease of access from the kitchen
  • climate and micro-climates
  • slope
  • vertical space
  • sufficient depth of soil (15 to 30 cm / 6 to 12 inches)
  • how much you want to grow

As a generalisation vegetables need at least 6 hours of sun each day, sunlight is particularly important in cool and temperature climates. Without sun, the fruits will not ripen and the plants will be stressed. There are a some crops that can survive in light shade or less sun, such as lettuce and other greens, broccoli and cole crops (that is the cabbage family).  And in warmer climates plants don’t need quite as many hours of sunlight.

If you don’t have a spot of full sun then the range of vegetables will be greatly reduced. One option to consider is growing your veggies in pots that can be moved as the angle of the sun changes during the year. Even if you can’t grow a wide range of vegetables, some home grown salad leaves and herbs will still be a delight on the table.

My Backyard

The house block runs east-west, and slopes slightly to the north west, resulting in lots of sun and little shade in the backyard, with no problem trees.  Despite the fact that I live in an area of moderately steep hills, the back-yard is almost flat, so the slope will not make gardening difficult, but it does add slightly to the sun exposure.  Please don’t get confused if you live in the northern hemisphere, you will need a south facing slope.

I have chickens which produce eggs and manure (well there is only one now, but she will soon have some friends).  One of the problems I have had in the past is that the hens would find the veggie garden too tempting and would dig up my crops at the most inconvenient time.  Now many people will cage their chickens to allow their  vegetables to free-range in the yard.  But I have always found that its the hens that get bored, need exercise, and generally benefit from being free-range, where as vegetables don’t mind being in a cage at all.

vegetable garden planning

Vegetable garden planning - first assess the backyardVegetable garden planning

This garden has a conveniently fenced area that would be a perfect site for my new vegetable patch.  I envisage a row of raised vegetable garden beds along the inside of the fence.  The fence could be used to support some tall or climbing plants.   Perhaps also a passion fruit vine running along part of it.  One end does have a couple of bushes and a fence that shade that section of the yard, making it a less appropriate site for the vegetable beds.

The fenced area is also the best place for the chickens, so I am consdiering dividing the area so that the chickens can take advantage of the shade and protection of the bushes, whilst the veggies have the sunny end of the area.  Having both the vegetables and the chickens in the fenced off area leaves the other half of the yard for other activities like bar-be-ques, playing children and dogs.

vegetable garden planning

The concrete slab is in the prime spot for the vegetable garden

One obstacle of the fenced area is that it contains a large concrete slab, where there was once a garage.  The slab is turning out to be even larger than I first thought, but I am not deterred by that.  The slab itself can be used for plants in containers, some sort of greenhouse or a work table.  Even if I don’t use it for those purposes, a raised bed can work well on a slab as long as there is a system for drainage from the bottom.  After all a raised vegetable garden bed is no different to a plant pot with the bottom removed.

The Front Yard

vegetable garden planning

Shade is an important factor in locating the vegetable garden

Along the front of the house are some concrete raised beds, that already contain a few herbs and strawberries as a legacy of the previous gardener. There is even a grapevine which grow up the balustrade of the front steps.  Between the house and the trees these beds don’t get enough sun for vegetables, but the herbs are doing well. The grapes apparently have not produced decent fruit, so I will see if some t.l.c. will make any difference.

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