SOW THISTLE
This is the time of year I’m outside tidying up the garden, doing all the jobs that I should have done over the summer but successfully put off in favour of doing more exciting things. I’m usually arm-deep in the weeding, rocking out to the ipod, enjoying the tail end of a sunny day.
On one clean-up day, I had amassed quite the pile of weeds - chickweed, sorrel, miner’s lettuce and a huge pile of sow thistle - when it dawned on me I had made an enormous salad. I just needed to add an onion, tomato, feta and nuts!
This month we look at the edible and delicious sow thistle, a broad term for a number of different members of the Sonchus family of weeds found all over New Zealand (and pretty much the world). The most common one you’ll see is Sonchus oleraceus, pictured right.
We have a number of introduced species and a few natives. The sow thistles are in the same family as dandelions so technically they’re not actually thistles but members of the sunflower family - let’s say MILTON MUNRO is a soil and plant scientist for rural supply company PGG Wrightson. He looks at common pasture weeds you’ll find on your block and how to deal with them. they’re distant cousins to thistles.
The term ‘sow thistle’ comes from the plant’s use as an animal feed. It was fed to lactating sows as the milky latex that sow thistles produce when cut was thought to improve milk production. But all grazing animals love to eat sow thistle, especially rabbits and hares, and the young leaves and stems are quite delicious in salads too, tasting a bit like lettuce.
In New Zealand, Maori have a special place in their hearts for sow thistle. It’s the ‘puha’ of pork and puha fame, specifically Sonchus kirkii, a native New Zealand sow thistle. If you can find it - it’s far less common now, possibly out-competed by introduced sow thistle species - it’s easiest to identify when at the rosette stage. Common sow thistle has dissected leaves like the ones you can see in the picture just above, while the puha leaf is whole.
However, the common sow thistle ( Sonchus oleraceus) is waaaay tastier so it is commonly called puha too.
Sow thistles are easy to identify: they are predominantly annual weeds and can germinate and establish pretty much all year-round. They begin their lifecycle as a flat rosette of irregularly-shaped leaves. This rosette produces a tall stem that secretes a milky latex when cut or damaged. Depending on the species of Sonchus, the stem can grow from 30cm up to a couple of metres. They produce a large number of small yellow-rayed flowers, which in turn produce a large number of fluffy seeds that are easily carried by the wind. As the plant ages it can change colour from a vibrant dark green to lighter green and even purple.
WHAT TO DO IF YOU WANT TO GET RID OF IT
Controlling sow thistle is a cinch, and I don’t say that too often. Sow thistles are very susceptible to mechanical control - you can pull them out pretty easily and if cut (with a mower or the like) they can’t regrow from the root. Animals will happily graze it, and you can pick it for pet birds, rabbits and guinea pigs.
If you want to use chemicals, almost any herbicide will do the trick.