All flowers, plants and trees get the majority of the nutrients that keep them alive and in bloom from the soil in which they are planted. In this guide we’ll take you through some of the most effective ways to improve and balance the mineral content of your soil, ensuring that your garden is the perfect environment for flowers and plants to flourish.
Starting a compost heap at home is a great way to produce quality plant food for free whilst also greatly reducing the amount of waste you send to landfill, but sometimes even good compost can't provide enough nutrients to sustain your hungry plant life. Where this is the case there is a wide range of fertilisers, supplements and other products that can help to balance and replenish the content of your soil.
There are 6 primary food groups that plants need in order to thrive. Carbon, hydrogen and oxygen are abundant in our atmosphere and freely available anywhere you’re likely to see a plant. The other 3; nitrogen, phosphorous and potassium, however; can be more difficult for plants to obtain in their natural environment and will need to be topped up regularly in order to provide a balanced sustenance for your plants.
The PH balance of your soil refers to how acidic or alkali your soil is. Different plants favour different conditions, in most cases though you’ll want to maintain a neutral rating somewhere between 6.5 and 7. Certain plant types or supplements can end up throwing this balance off and creating a more difficult environment for your plants to grow. Using a PH tester you can easily measure the acidity of your soil and take action if needed. If the PH is too high you can use an acidic substance like sulphur to neutralise it, if it falls too low wood ash or lime will bring it back up.
The NPK number, found on the label of most fertiliser bags, signifies the percentages of Nitrogen (N), Phosphorous (P) and Potassium (K) that the fertiliser contains; for example if the number reads 10-15-20 that fertiliser contains 10% nitrogen, 15% phosphorous and 20% potassium. The other 65% is usually clay, limestone or another inert material designed to ensure even distribution and prevent chemical burn.
Fertiliser usually comes in two forms, liquid or granulated. Both have advantages and disadvantages, so pick the one that best suits your needs. Liquid fertiliser usually comes in the form of a concentrate that can be added to water, either in a watering can or with a hosepipe attachment. This type of fertiliser is fast acting and will need to be reapplied every few weeks.
Granular fertilisers are applied dry and watered into the soil, these can be easier to use because you can see exactly how much you are using and where it has landed. Granular fertilisers also will not need to be reapplied as often, quick release formulas will last for around 4 weeks and specially coated slow release formula can keep your soil enriched for up to 12 weeks.
Different plant types have different requirements; the way you feed your plants can also influence whether they choose to flower heavily or produce lots of fruit. Universal fertilisers are available and can bring good results in areas where you have a lot of different species close together; however, you might want to consider a fertiliser mix which is specifically tailored to the needs of your plant.
Certain fertilisers can give a real boost to your fruit and vegetable crops. Specially tailored fertilisers exist for most common species like tomatoes and potatoes, designed to give your plants exactly what they need for maximum production. Universal fruit and vegetables can also be a great help in allowing you to fertilise multiple crops and containers all at once.
Many larger plants will benefit from some extra nutrition in early spring, to ensure a full blossom. For fruiting trees it’s also a good idea to use a tailored fertiliser again later in the season to help the fruit grow healthily.
There is a whole range of products available to cater for the health of your houseplants; in most cases it’s best to use a liquid feed that you can mix in with your watering can.
Different plants favour different conditions, the best way to find the right fertiliser for your plants is to find out which nutrients they need most in order to thrive, and which may be deficient in your soil, then pick a fertiliser with an NPK balance that reflects this. This doesn’t mean that universal fertilisers are useless; they can provide all that you need, particularly if you know your species and plant intelligently to avoid competition over one substance.
A well balanced fertiliser can give a real boost to plant’s growth, health and quality, most are easy to use; but it still takes some knowledge and effort to create and maintain your perfect garden. Fertilisers and other tools need to be used properly in order to get the best results:
Some fertilisers are formulated to work in a particular way, in certain conditions or at a particular time of year, and may be damaging if these instructions are not followed correctly. Always check the ingredients as well and know exactly what you are applying to your garden.
Water is the most important nutrient for any plant, there is no type of fertiliser that can reverse the effects of dehydration. See our guide for some tips on watering effectively.
Fertilisers should always be applied at the base of a plant, allowing the root system to soak it up and strengthen the plant from the bottom up. For hard to reach areas a liquid feed might be easier to apply.
Getting the timing right can greatly affect your fertilisers performance; remember that liquid feeds will be absorbed faster than granules, that granules can be purchased with a range of release feeds and that periods of heavy rain will cause the fertiliser to dissipate more quickly.