When the leaves on your plants start turning mottled colours or they begin to wilt and drop off without any explanation it may be a clue that your soil is having a few issues. It could be too alkaline or acidic, it may be missing some essential nutrients for the type of plants that you’re growing or it may even be that there is just not enough organic matter to give your soil the structure it needs.
The biggest areas of trouble that most people have with their plants are (1) pests, (2) virus strains and moulds, and (3) their soil. If you get the soil right you may have inadvertently fixed the other two because healthier plants can usually ward off, or at last handle, an attack from pests and diseases.
So how do you know whether the problem is with the plant or with the soil?
The more experience you have as a gardener will help you to answer this question. You can probably tell instantly that the leaf discolouration you’re shrub is experiencing is from a lack of manganese, or the stunted growth your plant’s suffering is due to a lack of magnesium. While this is great when you’re experienced you have to start somewhere and learn the basics.
The best way to begin learning about your soil is by analysing it with a soil testing kit. These are usually available from your local nursery or hardware store and can vary in price and the things they analyse.
What to expect in your soil testing kit
The very least you should expect from any testing kit is an analysis tool that can test your soil for it’s pH levels. This test will show whether your garden is becoming too acidic or alkaline or possibly if it’s neutral. None of these conditions are bad in them self but they could be if your plants are requiring a specific soil type. For instance, if you have a garden bed filled with camellia’s, gardenia’s and azaleas you would want your soil to be fairly acidic (approx 5.0 – 6.0 pH). Alkaline loving plants prefer a soil of 7.8 to 8.5 pH.
The test kit should also be able to measure the amount of nitrogen (N), phosphorous (P) and potassium (K) in your soil. These readings can help you find out the cause of some of the problems with your plants. If there is too much nitrogen the leaves of your plants will burn.
How to remedy your soil after you have tested it
If your soil is becoming too alkaline you may want to change the brand of fertiliser you’re using because it may be made up of too much salts. Try mulching with compost or adding blood and bone to the soil plus other composted manures rich in nitrogen.
If the soil is becoming too acidic, lay off composting as a mulch and add some lime to the soil.