What is fertiliser?
What exactly is fertiliser?
Fertiliser is a natural or synthetic substance that is added to the soil to promote plant growth. It contains nutrients that help to keep your plants happy and healthy. Fertilisers can be organic or inorganic.
The basic plant nutrients are nitrogen, potassium, phosphate and magnesium. These are often referred to as NPK for short (nitrogen-phosphorus-potassium). The first number always represents nitrogen, the second phosphorus and the third potassium.
Why do plants need fertiliser?
There are all sorts of nutrients that your plants need, and in a good compost there will be plenty of them already. But depending on what you grow, or how you manage your soil, sometimes your plants need extra help. Nutrients can be washed out of the soil, for example, or taken up by strong-growing plants and not replaced.
When to fertilise
Adding fertiliser to your soil is a great way to encourage plants to grow healthy and strong, but it’s important not to add too much or you could risk burning the delicate seedlings. This can happen if you use too much fertiliser in one go, or if you keep adding fertiliser when it’s not needed.
However, a little bit of added nutrients can help your plant thrive. Here are the best times to use fertiliser:
- When your seeds have germinated and are starting their active growth stage (also known as ‘vegetative growth’)
- When your plants have stopped growing but have started flowering
- When your plants have finished flowering and are now producing fruit or vegetables
How to apply fertiliser
If you want to fertilise your seedlings, make sure you get the right type of fertiliser: a liquid feed is best. It’s very easy to use and is readily available from most garden centres. All you need to do is mix it with water in the recommended amounts and then pour it into the soil around each plant.
Some gardeners like to fertilise as soon as their young plants are potted on. However, I don’t find this necessary if there’s plenty of organic matter such as compost or well-rotted manure in the soil mixture. In fact, I wait until my plants are about four weeks old before feeding them for the first time. If your seedlings have outgrown their seed tray, now’s the time to re-pot them into a larger container or pot – and that’s when you need to give them some feed too.
Fertilising is an important part of you plant’s care.
Fertilising will help to give your plants a boost and keep them healthy by providing nutrients that are essential for strong and vigorous growth.
Fertilisers are like plant food, they provide the essential nutrients that all plants need to grow.
There are 3 key nutrients that plants need to be healthy: nitrogen (N), phosphorus (P) and potassium (K). These elements make up the first numbers (which should be bigger than the last two) on any fertiliser bag.