Homemade Plant Fertilisers

Nettle Fertiliser

Ideal for heavy-feeding crops such the brassica family.

Taken from www.nettles.org.uk

nettleNettle leaves can be used to make an easy to use, if somewhat smelly, plant food. Best of all it's free!

To make your nettle fertiliser you will need only four things:

  • Nettles! - obviously.
  • A watertight container - a large bucket is adequate.
  • Water, and
  • A wait, sorry a weight. Not essential but makes the process easier as I will explain.


  • First take your nettles. These are best as young stems but can be taken at any time. Quicker results are obtained if the nettle stems and leaves are bruised.
  • Then crush them. This can be done by scrunching the stems in gloved hands or by placing the stems on a freshly mown lawn and using your mower to chop and collect the nettles at the same time. The addition of a few grass clippings that results from using this method does not affect the quality of the finished product.
  • Immerse in water. Stuff the crushed stems into your bucket. Place your weight on top of the stems. You may have to use a little ingenuity here - I have used a broken paving slab in the past. A brick and a piece of wire mesh cut to suit the cointainer serves equally well. Fill the container with water sufficient to cover the nettles and...
  • Leave to brew. This is where the original wait comes in. You may also consider placing the bucket away from the areas in the garden that you use most as the soup tends to get rather smelly.
  • Dilute to taste. After around three or four weeks the liquid should be ready for use. The mixture should be diluted until it is tea coloured - usually around 1 part liquid to 10 parts water. Water liberally around or on the plants and see the benefits.
  • Repeat until winter. Continue to top up your container with more leaves and water through the year. As autumn sets in put the remainder of the feed and the sludge in your compost heap. Give your container a rinse and store for next year!

Nettles make a nitrogen-rich fertiliser (promoting stem and leaf growth), so you need to know which of your crops will benefit most from it. Below is a list of crops and their nitrogen requirements (from www.allotment-garden.org).

Very High Nitrogen

  • Brussels Sprouts
  • Cabbages
  • Rhubarb

High Nitrogen

  • Beetroot
  • Celery
  • Leeks
  • Spinach

Medium Nitrogen

  • Broccoli
  • Calabrese
  • Cauliflower
  • Lettuce

Low Nitrogen

  • Asparagus
  • Runner Beans
  • Parsnip
  • Swede
  • Onion

Very Low Nitrogen

  • Carrots
  • Radish
  • Peas
  • Broad Beans

You can see the crops in the top row are the the ones to use the nettle fertiliser on. Do not use on onions, beans and peas.

You can also use the same fertiliser recipe for grass clipping fertiliser - just leave for a few days.


Coffee Grounds Fertiliser

Taken from frugalliving.about.com

You will need:

  • Used coffee grounds
  • Baking tray
  • Newspaper


  • Line a baking tray with newspaper.
  • Spread your used coffee grounds out on the sheet, and allow them to dry completely.
  • Sprinkle the grounds around the base of your acid-loving plants. Azaleas, roses, rhododendrons and blueberries are just some of the plants that will benefit from this treatment.
  • Be careful not to over do it with the grounds. Even acid-loving plants can get too much acid.

Grounds from a drip coffeemaker are better than than the boiled grounds from a percolator. The drip grounds are richer in nitrogen. Throw any spare grounds not being used for fertiliser on the compost heap.

Coffee grounds are also great for tomato plants.

Coffee grounds make superb fertilizer for growing carrots - just mix the dried grounds with your seeds before sowing. Radishes are good plant-buddies to carrots: radishes planted in the same rows as carrots break the soil for delicate carrot seedlings and are natural preventers of overcrowding. And, when the radishes are harvested before the young carrots are taken out of the ground, the carrots will grow into the space vacated by the radishes (http://www.localharvest.org).


Comfrey Fertiliser

Comfrey is high in potash - great for flower and fruit production, perfect for tomatoes.

Taken from www.gardenersworld.com

You will need:

  • Comfrey leaves
  • A large bucket or tub trug
  • Stone or flag, to weight the leaves down
  • Plastic bottles, such as old milk bottles
  • Watering can

Do it: May-September


  • Harvest comfrey leaves from the base of established plants. The hairy leaves can irritate the skin, so wear gloves if necessary.
  • Remove flowers and tough stems, then chop up the leaves and pack them tightly into a water-tight container. If possible, choose a container with a lid, as the solution can smell as the leaves break down. Use a brick to weigh down the leaves.
  • Check on the progress every few weeks. The leaves will break down gradually, releasing a smelly brown liquid. Top up with fresh leaves and collect any liquid, storing it in a cool, dark place.
  • Dilute the collected liquid at a rate of one part comfrey to 10 parts water - the darker it is, the more you'll need to dilute it. Use the solution as a potassium-rich liquid fertiliser to encourage flowers and fruit set.

You can also make a liquid feed using the leaves of bracken, clover, groundsel, nettles, borage, chicory and strawberries