Although we had developed and maintained gardens in the past our purchase of a small commercial chestnut, cherry and berry orchard required a lot of learning about soils and fertilisers.

This article is a personal response to the bewildering array of advice and types of fertilisers available. Most of the specific advice is summarised from L Glowinski "The Complete Book of Fruit Growing in Australia" Lothian, and P Baxter "Growing Fruit in Australia" Macmillan. These books are available through New Leaf Bookshop in Manjimup, and are essential for anyone serious about fruit growing in the backyard or on small holdings.

It is also important to know the property’s fertiliser history, soil type, soil acidity (pH) and water quality. For example when we purchased our property it had some jarrah chip mulch, no composting, and the weed control was chemical. We have composted extensively, and grown field peas, clover, lupins and chick peas. We have also grown wheat and barley which is mown off occasionally for the chooks, bantams and guinea fowl which are our insect controllers. Heavy cropping removes significant quantities of minerals from the soil, and these need to be replaced by inorganic fertilisers, or large quantities of manures and compost, or a mixture of these. A problem with manures and compost is that they may be deficient in a particular trace element and have variable levels of N (nitrogen) or P(phosphorus) or K (potassium).

Soil testing is advisable to see what is available for plants. Soil acidity can be inappropriate for some plants, causing them to be unable to extract the minerals which are present in the soil. Also clays have a lot of potassium in them but plants on clay soils may become potassium deficient because they are unable to extract the potassium away from the attraction of the surrounding minerals. What soil testing does not test therefore is whether the plants concerned can actually take up those minerals. Leaf testing however shows what the plants are successfully extracting. This service is available through rural merchants.

Assuming that what is applied is used annually, we use four fertiliser mixes, or six if Sue’s roses are included. The details and a spreadsheet to calculate your needs are on our web page.