Organic liquid feeds - how to make your own

Liquid plant feeds are an invaluable way of ensuring your plants don’t run out of steam - particularly those growing in pots. By providing nutrients in a soluble form, liquid feeds provide an instant ‘hit’ that the plant can take up quickly.
You can water with them, or spray direct onto the leaves.
Here's how to make your own - it’s simple, sustainable and free!
1. Plant-based liquid feeds
The two best plants to use are comfrey and nettle.
  • Comfrey Russian comfrey (Symphytum x uplandicum) makes a brilliant liquid feed.  It contains almost exactly the right balance of the key minerals used in any commercial plant fertiliser – nitrogen, potassium and phosphate. These will help with growth, as well as flowering and fruiting. You can use the comfrey brew anywhere, but particularly on your tomatoes, beans, container plants and flowering clematis.
  • Nettle Nettles also make a good plant feed – they have more nitrogen and less potassium than comfrey, so they are best for feeding leafy greens such as salad leaves and brassicas.  Select younger leaves, as they contain more nitrogen and less tough cellulose and lignin, so they break down quickly in water.
Making the feed
The joy of a home brew is that you can choose your quantities.  From a small bucket to a large barrel – all you need to do is steep the leaves in water. Or you can use a compression method to make a more concentrated extract. The latter is a little more effort but far less smelly!
Steeping: Fill a container half to three quarters full with leaves, top up with water, then cover. It’s as simple as that.  Wait 3 – 4 weeks, then strain the solution off.  There’s no exact science to this, but you can dilute the mix with water to get the colour of weak tea, just before it is used. Make sure you have a tight fitting lid as it can get quite smelly!
Compression: For the compression method, find a container with a hole in the bottom and fill it with leaves. An upturned 2 litre plastic lemonade or milk bottle with the bottom cut off works well. Place a weight on top of the leaves to compress them and a vessel underneath your container to catch the concentrated brown liquid. The liquid will be ready in a few weeks, and should be diluted with approx 10 parts water prior to using, again aiming to achieve the colour of weak tea.
2. Compost tea
Brewing a 'tea' from your homemade compost is a good way of extracting the nutrients into a form that the plants can take up rapidly. The simplest method is to one-third fill a bucket with mature compost, then add water up to the top. Leave to brew for 1 week, then strain the resulting liquid. Suspending the compost in a permeable sack, like a large teabag in the water, will give a better extraction. This should be diluted with 10 parts water prior to using.
3. Weed tea
Soaking your weeds and their roots can create a mineral rich feed.  Many perennial weeds, such as bindweed, ground elder and dock should never have their roots added to the compost heap.  They won't break down, and will subsequently spread the weed when you later apply the compost to your beds. Instead, 'drown' them in water. The technique is similar making to nettle liquid: pack a sack, bucket or dustbin with roots and foliage and leave to soak for a month at least.  Strain, and use the liquid feed as you would nettle or comfrey tea, to feed the soil. If the roots are completely mushy, then it is safe to add them to your compost heap.
4. Horsetail tonic
Owners of horsetail-infested growing areas needn't despair.  Soaking this pernicious weed will create a 'tonic' for other plants, as it is rich in minerals, particularly silica. Either proceed as for nettle or comfrey liquid, or - for smaller quantities - fill a large saucepan with washed horsetail stems. Add sufficient water to cover, bring to boil and simmer for 1 minute. Allow to cool. Dilute in equal parts with water. Spraying with this solution regularly creates an environment on the leaf surface which is unsuitable for fungal spores, such as potato blight, to germinate on.The spray needs renewing quickly after rain.
Go on – give your plants a brew!
See here  for more information on comfrey - how to grow, and how to use this wonderful plant.