Slash or burn?

After attending Ian Tolley’s citrus masterclass at Heronswood, I was all inspired to get our Homeland citrus orchard back in shape, which has been neglected a bit of late.  When we replaced a few problematic little trees, we made an alarming discovery and this in turn spawned the interesting debate – to slash or to burn?

In my state of inspiredness after the citrus masterclass, I bought 5 good looking citrus trees – 2 lemons (a bush lemon and a Lisbon, the latter as recommended by Ian), 2 different native limes and a hardy grapefruit. In my defence, very few people left the Diggers Nursery after the masterclass without 2 or more new citrus trees in hand – all I guess to go and correct their wrongs of the past. OK not everybody bought 5, but if you do the math, about 40 students times 2 trees each is not a bad day’s business in addition to the course fee and the regular trade. But I’m side-tracking…

Back home, I replaced 4 struggling little trees with my new acquisitions – this time all planted correctly using wide mounded-up holes with good organic chicken manure. I started with the bush lemon at the back of the orchard, near the school fence, where it is a bit dry, and it was a straightforward redo of the hole and then plant. The new grapefruit next to the Dreamland gate was similar.

Citris new grapefruit and Dreamland entrance

New grapefruit at the entrance to Dreamland

I couldn’t find a tree battling enough to sacrifice for the fifth – the Lisbon lemon – so I found a really nice sunn protected new place for it over in Dreamland. Straightforward dig, prep and plant.

Now you may be asking, what about trees numbers 3 and 4, the two limes? This is where it got really interesting! Two little trees at the side of the orchard near the house were battling. After a year they were each only a foot high, with not much new growth – I thought it was all due to frost damage. That is, until I tried to take the first one out, a lime kumquat. The poor thing had no chance! The whole root ball was one solid woven clump of couch grass roots! No wonder it battled and no wonder the frost hit it so badly – it had no strength and no way to compete for water or minerals. The little lime next to it was the same story. So I dug their holes very wide, tried to remove all the couch and planted the two new limes in there.

There were two more little trees in that same row which I subsequently dug up, cleared their roots and replanted them. I hope they survive the emergency operation, but without that treatment they would just have been strangled very quickly as well.

Citrus the hole and couch

The little tree, the hole and the couch ball

A while ago when we thought we had lost the couch battle we thought we would just mow it short and have a couch lawn between some of citrus trees – it will look nice when it’s green and neatly trimmed, right? Big mistake I tell you! So we learned the expensive lesson (in terms of lost growth and in needing to buy new trees) that we need to battle the couch full-on – so now it’s war! But how do you battle the couch when it just breaks off when you try to pull it out? And you can’t keep fiddling between the citrus roots either. They’re fussy little plants with very fine and shallow roots.


During the masterclass, Ian recommended an organic herbicide called Slasher. I bought 4 litres of the stuff to try out after the course – after all Ian is dead-set against Monsanto and their pure poison glyphosate-based herbicides.

Citrus and Slasher

But now the debate started in earnest at home. In the 5+ years we have been at Homeland, we have never used any poison – no herbicides, no insecticides, nothing – we are as organic as you get! We catch mice in traps. But now what about this Slasher stuff? I fell for the “organic” label, but Patricia was dead-set against it.

So here is the official blurb (copied from the OCP website):

Slasher Weedkiller is a Registered Organic herbicide that rapidly kills weeds, moss, algae and lichen.  Use it in gardens, paths, driveaways, around buildings and as a spot spray in lawns. It works quickly to easily control weeds the organic way!

Slasher Weedkiller is a non-selective contact weedkiller.  Thorough coverage is needed when spraying because any parts you miss won’t be killed.  Take care when spraying around your favourite plants as any spray drift will also damage them.  Do not apply to wet weeds or if rain is imminent as the extra moisture will dilute the spray and weaken its impact.


Kills weeds, moss, algae and lichen on contact

Rapid action, desiccating plants within hours

Doesn’t require heat or sunlight to work

Can be used anywhere in the garden and around the house

Active ingredient made from plant oils (GM free)

No lasting spray residues (100% biodegradable within a few days)

Glyphosate free

Safe for pets and children once dried on foliage

Registered Organic for use in organic farms and gardens

I can tell you, we debated this one quite a few times over. We could see the couch killing off our citrus, but we don’t want to spray any herbicides either. If you read the warnings on the label, it sounds like any “conventional” herbicide. Don’t touch t, don’t get in your eyes, in case of contact wash for half an hour or see your doctor, and so on… However, in the end we decided to give it a go in the citrus orchard to try and get rid of the couch.

Initially it looks like it works very well, the couch literally dies off overnight. However, couch is a very strong and hardy weed. Almost as bad as its cousin kikuyu, which we’ve also got in some other places, but that’s another story altogether. But after about two weeks, the couch starts growing back. The instructions warn that some hardy weeds may require multiple applications. I know we need to apply it on a wider area than we did in the photos, but now we’re wondering, how much of this stuff do we need, and are we ever going to get rid of the couch altogether?

Citrus with more couch growing back

Couch growing back pretty quickly

If we have to apply it say four times thoroughly over the whole orchard, that’s going to require quite a couple of litres – say about 40 – 50 litres as a rough estimate. That translates to a few hundred dollars. But then they say, you need a $200 dollar hole for a $40 tree (or some ratio similar to that). Maybe that’s just part of the $200 hole?


The only alternative we can think of is to burn the couch grass off and hope it dies that way. We actually have a gas flame wand to burn off the weeds in our paths, but I found is that if you want to get rid of a lot of weeds or grass with the gas flame wand, you quickly run through a canister of gas. You will literally work through a few hundred canisters before you make an impact on the couch throughout our little citrus orchard. It will turn into a very costly affair. I have seen some images of gas burners used in large vineyards that use big refillable gas bottles. Maybe the time has come to become inventive? But my other concern with this approach is that you have to be very careful around the irrigation pipes, and with our circular drip irrigation, the pipes lie wide around every tree, right there where you want to blast the couch grass! And I have pipes running quite shallow between the trees too.

What do you reckon, slash(er) or burn? Or do you have another organic or biodynamic approach?

Lessons learnt

We learnt the hard way that couch grass in any orchard is a no-no! It literally strangles the trees’ roots. We saw the same around some apple and pear trees in another area of Homeland too. But I can’t say we have found a good and effective solution yet. For now, we’re just giving the Slasher a go.

About (207 Articles)
My name is Martin Rennhackkamp, I now live happily in Lara, Victoria, Australia with my wife, two children and two dogs. My interests, apart from the obvious Organic, Biodynamic and Permaculture Gardening and Farming, include sustainable living, surfing, horse-riding, a wide variety of music, dancing, nature, birds, reading, Christianity and a few other things which I never get to...

2 Comments on Slash or burn?

  1. Hey Martin. Jip, it is always a tough decision. Just to get up to speed, have you tried black plastic sheets for heat killing? I would go with the Slasher, but does it not make the area around the trees more acidic? I see on the label that is an acid based product. Maybe do some soil testing in treated vs untreated soil? You might kill off some good guys in the soil as well.

  2. Hi Barry – thanks for the comment – it’s exactly that line of yours that I’m concerned about – “you might kill off some good guys in the soil as well”! We’re very focused on feeding the soil – biodynamics and all. Very interesting idea – I’m actually embarrassed that we haven’t tried black weedmat, because that’s what’s we’re using next door at Dreamland 🙂 but then again, with our harsh summer, that is going to get blazing hot around the citrus trees – I guess they’ll be OK with that as long as they get enough water?

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