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”!

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!

Tiny, annoying Rutherglen bugs

A couple of years ago we (and everyone else trying to grow fruit on the east coast of Australia) had a plague of these tiny bugs—have you seen them on your fruit?

They’re called Rutherglen bugs. They are tiny and a nuisance, and unfortunately there’s very little you can do about them. They’re a sapsucker, and if there are enough of them they can suck the juice out of your fruit and cause it to shrivel up.

The year we had a plague, some of our peaches had so much juice sucked out that they weren’t usable, but most were. The bugs can leave a slightly sticky residue on the fruit as well, but this washes off.

Interestingly, we’ve barely seen them since, which is often the way with ‘plagues’—they’re really just the result of an imbalance in the ecosystem that has temporarily favoured one insect over another, but they usually quickly get back into balance and numbers go back to normal (i.e., hardly , any).

Why does this happen? Mainly because they have a lot of predators, and nature tends to get these population explosions under control all by herself, as long as we have decent biodiversity in our gardens, and IF we don’t mess things up by using pesticides.

But, in the meantime, when you are experiencing an outbreak it would be nice to protect your fruit, right?

 

There’s a few things you can do:

  1. Hose the tree when it has a large swarm of bugs on it. This should discourage the bugs on the tree at the time, but if there are lots around in the garden the tree will probably be re-infested;
  2. If you have chickens or other poultry, confine them to the area around your fruit trees if possible – they will make short work of the bugs but, as above, if there are lots of bugs around, the tree may be re-infested when you
    remove the chooks;
  3. Protect the tree with a very fine net—the same sort you would use to prevent fruit fly getting to the fruit (because as you can see in the photo below, they easily get through regular size bird netting);
  4. As an absolute last resort, you can try a home-made organic spray, but be very careful if you do this, it’s easy to do more harm than good by accidentally killing the predator insects that will be eating the Rutherglen bugs, and you may just be perpetuating the problem.

So, the key message is don’t worry too much about them as there’s little you can do!

Concentrate instead on the long-term solutions for these bugs and all the other pests as well, which are (1) continuous soil improvement, and (2) continuous biodiversity improvement. In our experience if you stick to those principles, most problems like this are short term.

We go into more detail about the lifecycle, identification, prevention and treatment of Rutherglen bugs and 14 other common pests of fruit trees (including some recipes for home-made sprays) in What’s Bugging My Fruit?