Fertilisers

Different types of fertilisers

There are different types of fertilisers which are used for different purposes. General-purpose fertilisers have an N-P-K (the chemical symbols of nitrogen, phosphorus and potassium) rating to indicate the percentage weight of each nutrient, such as 5-10-5. Pay attention to these when shopping to buy fertiliser.

Organic fertilisers Derived from natural sources such as plants, animals, or minerals, organic fertilisers can be made using a variety of matter, including animal manure, bone meal and fish emulsion. There are plant-based organic fertilisers too, made from seaweed, nettles and digestate – a great choice for environmentally conscious gardeners.

Chemical fertilisers Also known as synthetic fertilisers, this type of fertiliser is manufactured and usually has a higher concentration of nutrients. Chemical fertilisers will often work quickly and can make a great last-ditch attempt at saving a plant.

Plant feed Although technically still a fertiliser, targets the plant specifically, whereas other fertilisers tackle the soil and, in turn, the plant. It's often used for house plants and short-term feeding.

FAQs about fertiliser for plants

How can I tell if my plants need fertiliser?

The signs will be there: yellowing leaves, slow growth and wilting or brown leaves. Remember, though, other issues can cause the same symptoms, so eliminate basic plant care (such as over-watering) and then start slowly with fertiliser and see how the plant responds.

How do I choose the right fertiliser?

A plant will benefit from a different fertiliser at different points in its development. Nitrogen (N) helps the growth of green leaves. Phosphorus (P) aids the development of roots and shoots. Potassium (K) promotes the development of flowers and fruit.

A plant in its early development would benefit from an N-P-K ratio of 5-10-5. However, a plant that's flowering may need a 5-10-10 fertiliser.

We recommend considering your garden's ecosystem, what ingredients you prefer to use and the plant's age when looking to buy a fertiliser.

How often should I fertilise my plants?

This will depend on many factors, such as the type of plant and what fertiliser you are using. A rule of thumb is to fertilise in spring, around April, when growth is resuming after winter. However, some plants, such as vegetables and lawn grass, will require more frequent application.

Can I use fertiliser on indoor plants?

Yes, indoor plants need some love, too. Liquid fertiliser and slow-release granules are great for house plants. However, be careful not to over-fertilise house plants. They'll need less fertiliser because of the limited space in their pot.

Have another question? Contact us here.

Why buy fertiliser from Marshalls Garden?

• Backed by gardeners: We're trusted by plant lovers all over the country. Thousands of you have given us 5-star ratings on Trustpilot.
• Specialist helpline: Have a question about your order? Not sure which product you need? Don't worry! Our expert team can assist you.
• Experience and knowledge: We've been making your gardens beautiful for over 75 years. From city gardens to allotments, if there's anything you need
  to create your sanctuary, you can find it at Marshalls Garden.

Express delivery: You can get fertiliser delivered to your door, sealed securely and packaged in eco-friendly materials.