In today’s tutorial, you’ll learn how to make your own potting soil, how to feed your plants, and how to maintain healthy soil during the growing season.

Potting soil

If you ever buy potting soil, the one thing you need to remember is never to buy soil that contains peat. Destruction of the peat bogs in this country is harmful not just to the local environment, but also, by releasing stored carbon into the atmosphere, to the global climate. If you want to know more about why compost containing peat is so damaging, visit Garden Organic’s I Don’t Dig Peat campaign page.

What’s more, you can make your own potting soil for a fraction of the price that you’ll have to pay at your local garden centre.

Making potting soil

For a good basic potting soil that you sow seeds in, pot on seedlings, and used for mature plants, you will need a mix that is two thirds well-rotted compost or leaf mould, and a third sharp sand.

Filter the compost or leafmould through a fine riddle so that it does not have large chunks in it and to introduce a fine, airy structure. Then mix in the sand. You can also finely shred comfrey leaves and mix these into the compost. The leaves will gradually decompose, releasing food into the soil for your plants.

If you are growing tomatoes, you can add milk powder and crushed eggshells to the soil mix as these feed your tomatoes and add calcium to the soil as well, which helps prevent blossom end rot.

Stop buying compost from a garden centre. Make a vow not to use peat in your garden at all, and start making your own potting soil.

Maintaing soil fertility throughout the growing season

Most of the tasks so far in this challenge have focused on creating a fertile soil which is ready to plant crops and plants in. But what about once you’ve planted the bed up? Don’t lose your focus on maintaining nutrient levels.

To ensure that your plants continue to receive adequate nutrients throughout the growing season, you should mulch around them regularly using an organic material. We’ve already covered a list of the best mulches that you can use in this post. Place large wodges of comfrey leaves under a heavier mulch as well, to feed the soil.

Organic plant feeds

Some plants, especially fruiting vegetables, need feeding regularly as well as well-prepared soil and mulches. Here are some of the best feeds that you can make at home

Nettle tea

Harvest bunches of young nettles early in the season, before they flower. Use a pair of thick gloves to do this, then chop them roughly with some shears, and leave in a bucket to soak for three weeks. By this time you will have produced an evil-smelling brew that can be diluted one part nettle tea to nine parts water and fed to your plants once a week. Nettle tea is high in nitrogen.

Seaweed fertiliser

You can gather seaweed that has been washed up on beaches and slipways, although do check your local bye-laws just in case there are restrictions on this in your area. Gather enough seaweed to half fill a bucket, and fill with water. Leave for three months. Use one part seaweed fertiliser to nine parts water when feeding your plants.

Comfrey tea

Fill a bucket with shredded comfrey leaves and leave to rot. Do not add water: the comfrey will rot down to produce a dark brown liquid that smells terrible. Dilute one part comfrey to six parts water.

Manure tea

Half fill a bucket with fresh poultry, horse or cow manure, and fill the rest with water. Leave for four weeks before diluting one part manure tea to four parts water.

Spent hops

Fill a bucket three quarters full of spent hops from a local brewery, and leave to soak for a month. Then pour the lot, including the spent hops, around the base of your plants.

Find a good local supply of any of the ingredients above and make an overwinter feed so that you are ready to feed plants in the spring. Plan to set up another bucket of homemade fertiliser in the spring.

The vital nutrients your plants need

Nitrogen: Promotes leafy growth

Potassium: Promotes fruiting. It is also necessary for photosynthesis to take place, and for plants to be able to take on the correct amount of water.

Phosphorus: Promotes root and shoot growth.

Magnesium: Promotes leaf growth and is necessary for photosynthesis.

Manganese: Necessary for photosynthesis.

Iron: Necessary for photosynthesis.

Molybendum: Encourages growth.

Boron: Needed for plant cell formation.