Why you absolutely do need to fertilise your garden
If you are fertilising your plants and thinking, “Do I really need to do this?” then read on.
The main reason for fertilising your garden plants is to replace lost nutrients. The second reason is because plants that come from soil with different nutritional content to your garden soil will need fertilising in order to grow. A third reason to fertilise is because over time an established plant will use up all of the nutrition from the soil around it. Need a fourth reason? Some plants that have been bred to be “producers” – think vegetable plants, your lawn, or roses – and need more of the good stuff in order to keep going.
Rather than thinking of fertiliser as food for plants, think of it more as something that helps your plants reach their full potential.
So what are the major elements that plants need to grow?
- Nitrogen – most important for leaf growth.
- Phosphorus – this encourages development of roots, seedlings, flowers, fruits and seeds.
- Potassium – helps give the plant strength, protect it from disease, encourage water uptake, and gives better quality flowers, fruits and seeds.
What types of fertilisers are there?
Organic fertilisers
- Animal Manures – While you do need a lot to make an impact (as their nutritional value is quite low), these are good for improving the structure of soil.
- Chicken and Sheep Manure Pellets – As the manure has been compressed and dried it will release the nutrients slowly over time.
- Blood and Bone – A great fertiliser that releases nutrients very gently. Made from the waste products abattoirs. Please note it doesn’t contain potassium.
- Green Manure Crops – A plant from the pea family (such as peas, beans, clover or alfalfa) is grown specifically as it can trap atmospheric nitrogen. It is then dug into the soil after it flowers.
Non-organic fertilisers
- Powdered and granular NPK fertilisers are available in various formulations depending on the plants you are fertilising (for instance lawns or camelias). They need plenty of water to help the soluble nitrogen dissolve and avoid root issues.
- Water soluble and liquid fertilisers will quickly dissolve when added to the watering can and then applied directly to the plant.
- Controlled release fertilisers are a revolutionary new way to fertilise and have become popular in nurseries. The fertiliser is covered with a protective coating, which means the nutrients are released slowly. It is also affected by temperature, which means more nutrients are released when the plant is growing and needs it.