Fertiliser Guide

Young seedlings

Plants naturally obtain their nutrients from the soil. When a plant dies or sheds its flowers and leaves at the end of the season, insects and bacteria break down the organic matter which deposit nutrients in the soil. Many gardeners however clear their garden, vegetable patch and greenhouse at the end of the summer and remove all of this organic matter which would become future plant food. Over time this depletes the soil of nutrients which reduces the chances of growing strong, healthy plants and a good crop of fruit or vegetables.

If however the material removed is composted into organic matter this is perfect for putting back onto the garden around the plants. The nutrients in the organic matter are returned to the soil to feed the plants.

If you can trench your spent foliage from fruit and vegetable plants at the end of the season and follow a crop rotation system you will greatly reduce the buildup of pests and diseases in the soil and some crops such as legumes naturally fix extra nitrogen in the soil.

If you wish to feed your plants with a fertiliser you have two choices, natural or artificial.

Natural Fertilisers are made from animal or plant material and in our opinion the most natural choice and the one we use. Unlike artificial fertilisers You will not know what the levels of NPK are (N = Nitrogen, P = Phosphorous, K = Potassium).

These include:

  • Composted material from your compost heap.
  • Comfrey - leaves can be used in the same way as nettles or you can cut the leaves and place around the base of plants for them to compost and feed the plants.
  • The diluted juice and compost from your wormery.
  • A liquid seaweed feed. We have bought some Maxi crop (organic seaweed feed) this year to see how it compares with our home made nettle feed. We will let you know at the end of the year.
  • Ash from a wood burner or bonfire. Ash contains water-soluble potassium, if mixed with water you can use as a foliar feed on chillies, tomatoes and flowers etc. Or you can sprinkle it directly on the soil around the plant to be washed into the ground when it rains or you water your crops.
  • Animal manure. Needs to be stored for 6 months before placing on or around crops. This should also destroy any weed seeds bought in with the manure. You can use it fresh if you are going to double dig into the beds in the Autumn/Winter when the ground has been cleared as it is too rich in nitrates and will scorch plants if applied fresh. 

We have used nettles as a foliar feed for our chillies along with our well-rotted pony manure for the chillies and sweet peppers, tomatoes, aubergines etc. grown in the ground in the tunnels. We dig the pony manure into the beds at the end of the winter. We also sprinkle potash from our wood burner around the plants.


Artificial Fertilisers are manufactured chemically. They are always sold showing the amounts of NPK. The amounts of each can vary depending on which crop you wish to feed. The disadvantage of artificial fertilisers is that they can create an imbalance in the environment and cause excess nutrients to leach into the water table or nearby streams and rivers.

Artificial fertilisers such as miracle grow will encourage plenty of soft sappy growth which makes gardeners think their plants are big and healthy however this soft sappy growth is extremely attractive to aphids. Therefore you are putting your plants at a higher risk of attack from pests at a time when they are still young therefore more vulnerable and less likely to recover. Fertilisers with a high concentration of nitrogen encourages the plants to put on plenty of green growth at the expense of flowers and fruits.

Chillies prefer Potassium and do not like too much Nitrogen.

We believe that it is far better to adopt a natural balanced approach and feed your plants using a natural fertiliser which is better for the environment and gives your plants the best start at the beginning of the season without encouraging unwanted pests. This will also help them develop into strong healthy plants naturally at their own pace which are more likely to survive the occasional pest attack without forcing excessive green growth at the expense of fruit.

If you are unable to make your own natural fertiliser and want to use an artificial fertiliser we recommend using a seaweed plant extract or an organic tomato feed.

Good fertiliser makes great chillies!
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