TYPES OF THISTLES
During the first couple of years at Highfield, we learned a lot about thistles – we had to, there were just so many of them.
“Are there different types of thistles?”, I hear you ask. “Aren’t they all just Scotch Thistles?” Ah, no is the short answer. Here is some of what we’ve learned about thistles.
More to thistles than Scotch Thistle
NOT ALL THISTLES ARE SCOTCH THISTLES
There are loads of different types of thistles. Just becasue it has a purple flower and spiky leaves doesn’t mean it’s a Scotch Thistle. Scotch Thistles are a particular type of thistle. I have seen Scotch Thistles once – on that flat plain west of Melbourne where there were hundreds, it was a grim sight. I have never seen a Scotch Thistle on Highfield – thankfully.
NOT ALL THISTLES HAVE PURPLE FLOWERS
When they don’t have purple flowers, they have yellow ones, but more on that later.
IDENTIFYING THE THISTLES YOU HAVE IS IMPORTANT
When we came here, there were thistles that towered over our heads – they had developed thick woody (albeit hollow) trunks. There were thistles that loved growing among the carex sedges, there were delicate little thistles that seemed to prefer growing in the shade and there were thistles that liked the dry slopes. The first thing we had to learn was which type of thistles we actually had. We quickly learned that we had several different types – Variegated, Black or Spear, Slender and Saffron. Identifying which thistles we had wasn’t just an interesting exercise in botany, it turned out to be crucially important in working out how to get rid of them.
THISTLES ARE EASY TO GET RID OF (OVER TIME) BY USING A WHIPPER SNIPPER
Yep, your whipper snipper. No need for spot spraying or boom spraying with herbicide, no need for exhausting chipping as the weed guides say. Get that blade tool onto your whipper snipper and merrily slash.
DIFFERENT THISTLES SHOULD BE SLASHED AT DIFFERENT TIMES IN ORDER FOR CONTROL TO BE EFFECTIVE
This is why it is important for you to know what types of thistles you have. I won’t provide you with descriptions of the different thistles. Grab yourself a weed guide take it into the paddock and have a look yourself. You will soon sort it out.
THISTLES ARE ANNUAL PLANTS
Again this is not just boring botany, it is important to understand this because it helps you work out why you are doing what you are doing. All annual plants, in this case thistles, put all their energy into producing flowers and setting seed. Then their job done, they promptly die leaving a bounty of seed behind to come up next season. The idea with all these thistles is to stop them from setting seed, which means stop them before their flower is pollinated and develops seed. If thistles grow and don’t get to flower and set seed you will eventually get rid of them! No thistles in the seed bank, yay!
What I am about to tell you cannot be found in those weed control guides. No one ever told us these strategies; we worked them out ourselves over a couple of years of observation and trial. So this my rough guide to eradicating different thistles without herbicides by using the blade tool on your whipper snipper. It’s rough, but it works.
VARIEGATED THISTLE
When we came here, Variegated Thistle grew in a forest that towered over our heads in what we call Kangaroo Valley. In other parts of Highfield, it pretty much dominated the grasses, especially in the spots where otherwise thick grass would normally grow.
If one can have a favourite thistle, then this is my favourite. It’s kind of like a giant cabbage, the leaves are relatively soft and pretty, and it is so easy to get rid of. You can wipper snipper this one at any time in its growth and if you cut it off low enough, it will not grow back. Avoid slashing it when it gets too tall because the stems get very woody and hard to cut. Easy and so satisfying.
BLACK OR SPEAR THISTLE
Timing is quite important with this one. If you slash it when it’s too young, even if you cut it off very low to the ground, it will put up two or three separate stems – a many-headed hydra, a nightmare. The best strategy is to slash it just as the flower buds are forming. Before they start to put out that purple flower. Slash them at this time, and they are gone and do not grow back.
Saffron Thistle and Black or Spear Thistle
SLENDER THISTLE
This is a delicate little thing. It can be hard to notice, it’s a bit tricky. You see it kind of pops up quietly – it doesn’t have an enormous rosette of leaves that announce it. I find that here it grows in the shade of big old trees. The stems are a little woody and very tall. This one, you need to slash like Black or Spear Thistle – just as the flower buds are forming. Because the flowers on slender thistles are so much smaller, they can flower and set seed quickly, so watch out for them.
SAFFRON THISTLE
As the name suggests, this thistle has a yellow tuft-like flower. If variegated is my favourite then saffron is my most hated thistle. It is so spiky and grows on dry slopes here, and that makes it harder to access. it is also very difficult to get the timing right on this one. You need to slash this one just as the flowers are opening – i.e. just when you start to see the first bit of yellow. If you slash it before the flowers start to emerge, the stem and flowers grow back. If you slash when the flowers are too developed, then they may have already set seed, and you are just spreading the seed around when you slash.
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If this is just too daunting, go on, get out the spray rig. However, there is an alternative. Combined with grazing strategies that ensure 100% cover of your soil, reducing and eventually eradicating thistles is absolutely possible over a few years by using these methods of identification of the thistle you have and slashing at the right time.
You can do it. If we can, you can.
This is what we call Kangaroo Valley. When we came here there was a forest of Variegated Thistle in the whole of this valley floor. Now there are just a few plants. I’m slashing these tomorrow.
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