PASTURE WEED WATCH Brought to you by

SCENTLESS CHAMOMILE OVER THE past three months you’ve read about the chamomile weeds, stinking mayweed and rayless chamomile, and now we tackle the last one, scentless chamomile. I’ve always loved these weeds from a training sense – they form a bit of a graduation exam for the agronomists I train. The scenario is always to correctly identify the three weeds as seedlings as it’s very hard to do visually. But if they remember what they’ve been taught and Why is it a weed? use their sense of smell it becomes an easy Competitor of crops test, and you can give it a go in your own and gardens garden – you might surprise yourself with Where is it found? your skills! All across New Zealand, but Scentless chamomile (Tripleurospermum in particular in Canterbury inodorum) is an annual (or a short-lived perennial in some situations) weed found Is it toxic? all over New Zealand. It’s native to Europe, No Asia and North Africa, but has moved most Alternative Uses? of the way around the world. In some parts None really

Photo: NatalieSchmalzWikimedia Commons (I’m looking at you North America) it is considered an invasive noxious species. As with the other mayweeds and hard to visually identify from a small plant chamomiles, scentless chamomile is a but super easy if you can crush it and smell How to control it member of the Asteraceae or sunfl ower it. They can also be differentiated by their Controlling scentless chamomile is a family of weeds, but there’s a little bit of very different fl owers. cinch but only if you deal to it quickly confusion over exactly where it fi ts in. For Scentless chamomile can germinate – let it seed and you will be fi ghting the a long time it was thought to be a direct in soil all year round, so long as there is fi ght for years to come. relation of rayless chamomile but genetic moisture, sunlight reaching the soil, and The best way to deal with it in a analysis has split this family in two with soil temperatures are above 3°C. Generally, home garden is just to pull it out as it’s half of them forming the new genus of most of them germinate in the spring not too hard to weed out. Tripleurospermum. and autumn in New Zealand. Following If you are dealing with a larger area Like the other mayweeds and germination they produce small, dense you may want to spray it out. We are a chamomiles, scentless chamomile is very rosettes of leaves which are very fi nely little limited in what chemical will work divided and kind-of resemble fern fronds. here: 2,4D and MCPA are ok; Versatill They soon produce a long stem (15cm works best but you need to be spraying to 1m), with a large number of branches the nose knows small seedling plants to get any control. covered in their fi ne leaves. If you crush the foliage of one If there is a fl ower, forget about spot At the end of each branch the plant of these very similar-looking spraying with chemical control as the produces fl owers with white petals and a weeds, your nose will tell you plant will have fi nished its lifecycle and brilliant yellow centre, kind-of like a giant which one you’ve got: die off naturally after seeding, ready to daisy. These fl owers produce a veritable • if it smells like pineapple, reproduce next year. I it’s rayless chamomile; horde of seeds – we are talking tonnes of seeds, like 10,000 to 200,000 seeds per • if it stinks, it’s stinking mayweed; MILTON MUNRO is a soil and plant! – which means they can effectively plant scientist for rural supply • if it doesn’t smell of anything, colonise large areas in only a couple of company PGG Wrightson. He looks it’s probably scentless chamomile. at common pasture weeds on years. That can be a real pain in pasture as blocks and how to deal with them.

Nadin333 | Dreamstime.com Nadin333 animals will not eat it.

www.nzlifestyleblock.co.nz 43