To fertilise or not to fertilise?

Crabapple flowers and leaves in spring
Crabapple flowers and leaves in spring

When your fruit trees start to flower, and produce leaves and then fruit in early spring, they’re using nutrients they stored away in their buds and bark back last autumn.

But it’s a pretty limited supply, and as soon as their roots are active, they’ll also start to draw nutrients up through their roots.

A young fruit tree with roots exposed
A young fruit tree with roots exposed

So, do you need to add fertiliser to the soil so they have enough nutrition available?

Well, no … but yes.

Sorry, confused? The organic way to grow fruit is called the Natural Fertility System. It’s the system that evolved millions of years ago without any human intervention, so it works with nature rather than against it.

A pile of woody compost with a pH kit
A pile of woody compost with a pH kit

Soil is one of our favourite topics, and we support home gardeners with a bunch of different short courses (we’d love to see fertilisers disappear off the shelves of garden shops!), but probably the best place to start the soil journey is Is My Soil Healthy?

Turns out that the addition of man-made, artificial fertilisers (which are soluble nutrients) – though they seem to give good results – actually works against this principle.

Hugh checking the temperature of the compost pile at Rodale Institute of organic research
Hugh checking the temperature of the compost pile at Rodale Institute of organic research

Rather than supporting the populations of microbes, artificial fertilisers kill microbes, upset the delicate balance in the soil and actually destroy the Natural Fertility System. And guess what? That means you become dependent on the fertilisers for nutrition for your crops

This explains how the great promise of the “green revolution” (when nitrogen fertilisers started to be mass produced) turned out to be a trap for farmers and gardeners all over the world. The ensuing collapse of the Natural Fertility is one of the root causes behind the devastation we’re now seeing in agricultural systems and ecosystems globally.

But staying away from fertilisers (and other chemicals) doesn’t mean we don’t add anything to the soil.

To keep our fruit trees happy and healthy, our job is to make sure that all the required nutrients need are present, and then to provide the right conditions to favour the populations of healthy soil microbes so they can do what they’re good at, which is converting nutrients into a plant-available form (and eating each other!).

Fruit trees mulched with straw in spring
Fruit trees mulched with straw in spring

So what to add?

Basically any organic matter, and from a variety of sources if possible. This might include:

  • compost
  • worm castings
  • wood ash
  • rock dust
  • wood chips
  • straw

Basically, if something used to be alive, it’s organic matter!

6 thoughts on “To fertilise or not to fertilise?”

  1. Love all your hints. I try to keep it all natural. Is Seasol useful or is that also an interference rather than an assistance?? It’s the only additive I have ever used, and probably only a couple of times a year.

    1. Hi Maureen, no Seasol is great – it’s what we call a “soil conditioner” rather than a fertiliser, because it’s acting as microbe food, rather than artificial fertiliser. Once a month during spring and summer isn’t too much, but it’s relatively expensive to buy of course, so we also favour free sources of organic matter if you can find them!

    1. Hi Catherine, we don’t recommend or endorse any particular products or companies as we’re much more in favour of low cost options (like having worm farms, including animals in the garden, making compost and sourcing the actual ingredients in this kind of product), but it is a certified organic product and should be fine to use.

  2. Hi Katie,
    I noticed you don’t include manure on your list – is that because it has too much nitrogen? I use a lot of chicken manure pellets but try to supplement it with compost etc.
    Thank you!

    1. Hi Marian, no manure is fine, but it does need to be aged first, and used in moderation – because yes, it has a lot of nitrogen in it and you don’t want to put on too much at once. The rule of thumb is the larger the animal, the more and fresher you can use.

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