Today that 1/4 acre block has slipped to about 1/6 of an acre. This means after deducting about 240 square metres for the house and car it reduces the effective usable space from about 860m2 down to 500m2. But is this enough ground to be self sufficient and create garden beauty as well?
The short answer is yes.
To grow all the food you need the garden space required is only about 40-60m2, because the vegie garden alone needs only about 40m2 of space. Now that we have such important modern advances as dwarfing root stocks for citrus and other fruiting trees another 20m2 will be enough for 5-6 dwarf fruit trees.
Let's start by stating that a family of four can be largely self sufficient with only 40m2 of space (about 10 squares per person), which is about the size of a two car garage.
At Heronswood we have demonstrated for 30 years that we can feed two people with over 200 kilos of vegetables, from as many as thirty different crops, utilising four beds that are 5 metres long. This presumes three seasonal plantings for sowing in spring, in summer and in winter from May-August. When you consider the well known heirloom tomato, Tigerella, can produce 20kg of fruit in 1m2 or that we can grow 100 carrots, 100 beets or 100 onions in a single square metre, that's potentially 20kg per metre as well.
So we can provide all our food for the average family with only 8% of our available sunlight. Those that want a bigger fruit garden could add another 20m2 for the planting of dwarf apples, pears, citrus, as well as raspberries and strawberries which would be only 12% of available space i.e. 60m2.
Whilst we must have maximum sunshine to grow healthy plants it would be best to ensure at least 20% of that area provided shade and effective cooling of the garden on the hottest days which would provide a space of about 100m2 i.e. 10x10 metres total.
This area should be large enough to provide about four average sized trees, preferably good deciduous shade trees like our Desert Ash on the main lawn at Heronswood or native evergreens such as Ficus hillii, which are both lush and green in summer and about 10 degrees cooler than a eucalypt on a scorching 40°C day.
This amount is of course entirely optional but if I were required to live in a domestic sized block instead of 1.2 hectares (12,000m2) at Heronswood I would want a perennial flower garden of at least 50m2 and if I included shrub roses and a shrub border then at least 150m2 would provide visual separation to create solitude from neighbours and for reading a book.
Of course each gardeners needs are different but if you want to play cricket and footy on the back lawn then about 200m2 would be needed allowing dimensions of say 10x20 or 8x25 metres.
Don't forget that a well watered lawn has a cooling effect on the garden almost as cool as a good shade tree or a swimming pool which in our climate are always 15°C cooler than the air temperature on a 40°C day.
That gives the garden a sun-to-shade ratio of 80:20, which works in HZ 1-6 but in hotter drier areas the need for shade may be as great as 50:50 so that the lawn is taken over entirely by shade trees. If the lawn is not surviving the intense heat then it can be best to use this space to grow shade trees and create a cooling effect. Every gardener's needs are different so this is but a guide to help you get the proportions of garden areas right whilst our Plant Finder and vegetable books leave that selection entirely in your hands.
You may have wondered how it is that we make the claim that it takes just five hours gardening a week to create a garden as productive and as beautiful as either St Erth or Heronswood. Well, our Heronswood garden is about the equivalent of 24 x1/6 acre blocks or about 500m2 of gardens. Our garden utilises the help of three gardeners at 115 hours each week so for a 1/6 acre block the figure is 4.79 hours per week. Doesn't sound much effort considering the pleasure, the health lifestyle and the happiness that this work brings.
