To mulch or not to mulch?

Our fruit growing study tour of the USA got us thinking about mulch, as we saw a number of different approaches to it in our travels.

An apple tree mulched with woodchips at the Maine Heritage Orchard
An apple tree mulched with woodchips at the Maine Heritage Orchard

Of course it wasn’t hard to find orchards where the weeds have been completely sprayed out with herbicide, and mulch isn’t needed because there’s no plants left.

Yuk! Don’t do that!

The chemicals are bad for your health, the weeds grow back and need spraying again ($ straight from your pocket to the chemical companies), but worst of all – it’s really bad for the soil and kills the natural fertility system that trees need to get their nutrients (more $ straight from your pocket to the fertiliser company).

So what to do? Should you just let the weeds grow? Won’t they compete with the trees?

For young trees this is somewhat true – it’s definitely helpful to keep the weeds (or you could call them precious understory biodiversity plants) down while the tree’s roots are getting established, and we saw this in action at the Maine Heritage Orchard in Unity, Maine.

This orchard was planted not that many years ago on the site of a disused gravel pit, so major soil building and remediation has been the order of the day.

Hardwood chips have been extensively used, not only to mulch the trees when they were planted, but also to build paths, build soil more generally, and as an ongoing weed suppression tool even as the trees mature.

A tree in Michael Phillips' orchard which was mulched with woodchips when planted and has since been allowed to revert to natural understory
A tree in Michael Phillips’ orchard which was mulched with woodchips when planted and has since been allowed to revert to natural understory

We saw a different approach in Michael Phillips’ orchard in New Hampshire.

He also uses woodchips on young trees, but welcomes a wide diversity of understory plants as the trees grow, using mulch in a more ad hoc way.

There is widespread agreement that if you are going to mulch, hardwood woodchips are preferable.

This is because fruit trees prefer a fungally dominant soil, as we explain in our Soil Biology and the Soil Food Web short course.

Understanding the amazing world of soil microbes that are key to the Natural Fertility System will change the way you think about soil, fertiliser and mulch forever.

So, to mulch, or not to mulch?

After everything we’ve seen, we’re still in favour of mulching while the trees are young, and then transitioning to either a natural or cultivated understory – a “living mulch”!

Fancy a cup of compost tea?

Having our morning cuppa - of tea, not compost!
Having our morning cuppa – of tea, not compost!

We’re always banging on about soil being the foundation of your entire food growing system, and how important it is to be constantly improving it.

So one of the common questions we’re asked, is “how?”

There are lots of techniques available to help you improve soil, like adding aged chicken manure, and compost (and we’re big fans of them). However one of the most useful (though least understood) is brewing your own compost tea.

We brew it on a big scale (as you can see in the photo below), but it’s also easy to make on a home garden scale.

Our 1,000 L compost tea brewer set up for demonstration at a workshop
Our 1,000 L compost tea brewer set up for demonstration at a workshop

So, what is it? It’s probably easiest to start with what it’s NOT, which is compost extract.

Compost extract is made by putting compost in water and swishing it around or leaving it to soak. You can do a similar thing with weeds to make a weed tea or weed extract. They’re both fantastic things to do, but all they do is to put the nutrients and any microbes present into solution.

This method doesn’t increase the number of microbes in the brew, and that’s the point of compost tea.

Hugh showing off his bathtub full of rich worm castings, which will be used to make compost tea
Hugh showing off his bathtub full of rich worm castings, which will be used to make compost tea

To brew compost tea we start with a small amount of something that’s rich in microbes, e.g., good compost, worm castings, or leaf litter from under a mature gum tree are all perfect for this. Then we put the source material in water, agitate it to knock the microbes off, then add microbe food and oxygen for 24-48 hours and voila! The microbes breed like…well, like microbes (that is, REALLY fast when conditions are right).

Components for the compost tea brewer
Components for the compost tea brewer

This turns a small amount of healthy microbes (bacteria, fungi, nematodes, and protozoa) into a huge number in a very short time.

On the farm we always check the brew to make sure we’ve actually got the right kind of microbes, but that’s not necessary in a home-brew situation, as long as you follow the guidelines.

Hugh checking the compost tea to make sure it's full of microbes (and not just brown water!)
Hugh checking the compost tea to make sure it’s full of microbes (and not just brown water!)

Then we just put the tea on the soil under our fruit trees, and let the microbes go to work. 

If you want to know more about this simple and very effective method of quickly building healthy soil, we’ve designed a short course just for you! It’s called The Art of Compost Tea, it includes plans for making a home-sized brewer, and you can download it here.

3 Ways to Love Your Soil

Do you think about soil much, or is it just something you walk around on, or maybe try to grow something in?

Dark, rich, healthy looking soil
Dark, rich, healthy looking soil

If you’re a farmer or gardener (as we know many of you are), you’re probably already aware of how important the soil is, and (like Hugh) may even revel in the smell, look and feel of beautiful soil.

Hugh sprung smelling rainforest soil
Hugh sprung smelling rainforest soil

But soil is so much more than most of us realise – for example, did you know that one-quarter of the world’s biodiversity lives in the soil!

How incredible is that?

Rather than being an inert, dead thing, it’s actually a thriving community of more microbes, worms, arthropods and other insects than we can even imagine, let alone count.

That is, if you’re looking after it properly!

Treating your soil badly by using chemicals, allowing compaction to develop, letting it get waterlogged or too dry, or consistently removing organic matter without replacing it can all create conditions that don’t help your fruit trees and other plants to thrive, and in fact encourage diseases to get established.

Filling new beds with soil at our farm shop to create a native garden
Filling new beds with soil at our farm shop to create a native garden

So, what to do? Well it’s pretty simple. We love busting the myth that “it takes 100 years to make 1 cm of soil”, because in fact if you do the right things, you can build healthy soil much faster than that.

The keys are:

  1. Consistently add organic matter to your soil (i.e., anything that used to be alive: compost, manure, mulch and worm castings are the most common)
  2. Add microbes to your soil, and then feed them regularly. Compost, compost tea, or worm juice are easy ways to add microbes, and they love to eat organic matter, liquid fish, and liquid seaweed.
  3. Have live groundcover plants under your fruit trees.

It’s also important to make sure there’s enough water (but not too much), and that the soil gets enough oxygen.

If you’re not sure whether your soil is healthy, we wrote a course just for you!

Fat juicy worms with lots of food in our worm farm
Fat juicy worms with lots of food in our worm farm

There are LOTS of techniques available to help you take these key actions in your garden. One of the most useful (though least understood) is by having a worm farm, which is much easier than most people realise!