OK, so you're wanting to grow yourself some vegetables, but you haven't got a vegetable patch? Here are some pointers for various methods of setting up a vege garden - from the quick and easy to the more dedicated, long-term approaches.
CHOOSING A SPOT
There are two very important points to consider when choosing a good spot for a veggie garden. These are sunlight and shelter. Other aspects like drainage, accessibility and soil type are also important but these are more easily overcome.
Ideally, you want a site that gets plenty of sunlight and is as sheltered as possible from wind. In Dunedin, the prevailing winds are from the South-West and the North-East, but we can get strong windy days from pretty much any direction through the year. For sunlight, you want your area to be open to the North.
In the end you need to make do with what you've got. There aren't many spots that are 100% ideal but as long as your patch isn't in the coldest, boggiest, shadiest corner of the section or subject to constant strong winds, you'll be able to grow something at least.
Now, take a good look at what is currently growing in the area you want to use. You will need to be clearing whatever weeds, shrubs or trees are occupying the spot or shading it out. Sometimes a decision has to be made between a wylie old rose bush or a lush productive veggie garden. If you're renting, it pays to check with your landlord before making any drastic changes. Most landlords will understand that a veggie garden is a good thing and will likely add value to the property.
CLEARING THE PATCH AND BUILDING THE SOIL
There are a few different options that you have for clearing the patch. The main goal is to rid the site of weeds, especially the particularly stubborn / invasive varieties like couch grass, dock, creeping clover, etc. It pays to invest time now getting them out as it will be easier than trying to get rid of them when your veggies are growing there. A grubber (looks a bit like an ice pick but the front edge is flattened and horzontal) is a good tool to use to get the weeds out by the roots.
If you're wanting to start a veggie patch on a lawn, one option that you have is to simply remove the layer of grass using whatever tools you have. Gardening gloves help prevent blisters from hours of continual hoeing. Cold beer is usually also a requirement. The 'sod' (the stuff you've hoed off) can be put into a pile somewhere upside down and may be useable in the future as soil again. After you've turfed off the area you want to use, one option is to build a border around the area that can then be filled with soil building materials. Bricks or planks of wood serve as good bordering materials, but you can use your imagination on that one. In fact one of the most important parts of gardening in general is using your imagination.
Fill your borders with any organic materials you can get your hands on...compost, soil, manure, seaweed, leaves, grass clippings, etc. You need to try to balance out gluggier ingredients like grass clippings and seaweed with lighter ingredients like straw, hay, compost, etc. A sprinkling of garden lime on top of fresh materials always helps in balancing the pH and helping things break down faster.
If you're in a hurry to get things growing you may find it easier to begin your garden with an initial application of outsourced compost / soil. Making a bed from more raw ingredients like straw and seaweed will take a few weeks at least to break down and be ready for planting.
Smother those weeds with a no-dig approach
One option is to smother out the weeds using layers of cardboard, newspaper, mulches, compost etc. For an area with tall growth of weeds / grasses, it can pay to weed whack it down first, to make the ground more level and to aid in the smothering process. Leave the clippings on the ground and cover with a thick layer of cardboard or newspaper. It still pays to try to grub out the worst of the perennial weeds before doing this as you would be amazed how easily they can burst through even the thickest cardboard layer.
Once you've applied your 'smother layer' you can add other ingredients on top, like straw, seaweed, manure, soil etc. The idea is that over the lifetime of the garden you just keep layering on alternating materials, which gradually break down and earthworms transport the goodness throughout the soil layer. Because the top layer is quite loose, any weeds that do emerge should be easy to pull out. It is important if using this method, or any method, to try to not compress / compact your soil. As such it is a good idea to make paths / designated foot placing areas. You can make these from wood planks, bricks, stones, etc. or just a naturally formed path in the dirt.
Gardening on top of concrete
Even if you don't have an already established 'garden' area to convert to veggie patch, do not panic. Everything's gonna be okay. I'm sure that almost any dwelling will have somewhere that can be made into a veggie patch. You can even garden on top of concrete. Simply make a border out of bricks or other materials, and fill it with soil, compost and whatever other good ingredients you may have at hand. Over time you can mulch with various things as per the no dig garden approach, and you will gradually build up a really great layer of soil for growing vegetables.
Double dug beds are a method of creating a deep soil layer by breaking up the topsoil and sometimes clay layers.
The first step is to remove the turf (grass) to a depth of 2 or 3 centimetres. You don't want the grass mixed back in with your soil as it will grow very invasively. After this, the soil is dug out of a bed to one spade depth (about 30cm), heaping the soil next to the trench. You can then add in extra goodies like compost, manure, seaweed, lime, gypsum, etc. and give it all a good mix around as you load the soil back into the trench.
Ingredients such as lime and gypsum assist in breaking down clay soils into smaller pieces, and make the soil more alkaline. Adding organic matter increases the nutrient content of the soil and improves its structure. The mounded nature of a freshly made double dug bed will settle down over the first few weeks.
Double dug beds can be planted with veggies after a week or so of having some time to settle, or beds created in autumn can also be planted in green manure crops if you prefer, to continue building the soil over winter ready for the spring planting. These green manure crops can include mustard, lupins and oats among others. See the green manures page for more detail.
The 'Hugelbeet': Long lasting garden mounds
Another option for making a garden is to construct yourself a 'hugelbeet', which is a form of mounded garden that contains lots of organic matter and will just keep churning out those crops for a few years without too much extra nutrient application. You can be creative with the specific ingredients used, based on whats available. The basic idea is coarser longer lasting stuff in the core, moving out through sod, leaves, seaweed, and topped off with a layer of compost/soil. Cool stuff!