For those who like doing things for themselves, one way of feeding the plants is to make your own liquid fertiliser. You can do this quite simply by using deep rooted plants like comfrey and nettles. These not only are high in potassium and nitrogen but also concentrate trace minerals from the subsoil.
It’s really quite easy. You can buy one or more of those 50/75 litre waterbutts they have in B&Q or Homebase plus a tap for them.
Stand it on some blocks or a convenient ledge (one advantage of the nursery is that we have plenty of these.) Fill it up with freshly cut roughly chopped comfrey and nettles (we sometimes put thistles in ours too) and then fill it up with water. Leave for 3-6 weeks and then you will be able to drain the stuff out into a handy containers (you can see why I told you to put it on blocks). You can then water it on the plants at a dilution of 10 to1 – beware – it stinks to high heaven so don’t spill it on your best clothes.
We of course suck it up into the irrigation system via the trusty dositron. The plants seem to like it.
Some people just fill the bucket up and weigh it down to ooze. You’ll get a stronger liquid which you may need to dilute up to 20-1
One problem to avoid is to stop the tap clogging up – you can either do it with a purpose designed item like this or just improvise with some broken module trays to keep the bottom of the vegetation significantly above the tap.
There’s even some evidence that if you have a high proportion of nettles in the mix it has some insecticide properties.
Above all – don’t drink it!