Running the Farm : Weeds
This section contains articles on weeds you may find on your farm and how to deal with them. There are hundreds of other useful articles in our lifestyle file. If you're looking for something in particular then use the search box above. If not, then browse the article titles and see what there is to help you. If you can't find an answer here then why not ask in our discussion forums? One of the very friendly and helpful members is sure to be able to help you.
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Tutsan is a semi woody, semi evergreen, perennial shrub that grows upto 1.5m tall. Barley grass is one of nature’s survivors. Not only does it grow where and when other grasses fail to thrive, but it has developed a flexible seeding technique which allows it to grow unnoticed until the day length, temperature and soil moisture level is suitable for seedhead development and dispersal.
Ranging from low weeds to large bushes the nightshades all have one thing in common – they are definitely not for eating. Of interest is the fact that, while we are likely to refer to the small varieties as ‘deadly nightshade’, that is actually a whole different species (Atropa bella-donna) which is extremely rare in New Zealand.
There are two native nightshades (Solanum aviculare and Solanum laciniatum) both known by their Maori name of ‘poroporo’. Tall and spreading bushes with long and heavily veined and hairless dark green leaves, green or purplish stems, trumpet shaped mauve flowers with yellow centres, and drooping single oval green berries which turn orange as they ripen.
Most pastures in New Zealand consist of mixtures of both grasses and clovers.
With un-mown lawns and pasture sprinkled with the cheerful yellow flowers of dandelions and other ‘flatweeds’ at this time of year it seemed a good time to investigate the various different species to find their names and characteristics.
“Write about fireweed” said a friend, “I’ve got it growing all over the place”. But ’fireweed’ is one of those all-embracing terms which attaches itself to different plants in different places. And all these plants have one thing in common – they are the first to colonise soils exposed by forest fires or forest clearing.
Has a cheerful yellow tinge spread across the tops of your pasture in the last month? If so, it’s just the various buttercups telling you “Here we are again!"
Topping two or three times a year, and a follow-up grazing, provides very good Californian thistle control.
Stinking mayweed is an annual that grows up to 40cm high and flowers from December to March. Flowers are white and yellow and 15-30mm across. Leaves are feathery and dark green, grow up to 8cm long and are divided three times into awl shaped segments.
Black nightshade is an annual to short-lived perennial plant that has white or mauve flowers followed by berries that are first green, but change to black as they ripen.
The new interest in ornamental grasses is potentially bad news for Northland farmers.
Stinging nettle is an erect annual that grows up to 60cm tall.
Stinking mayweed is an annual that grows up to 40cm high and flowers from December to March. Flowers are white and yellow and 15-30mm across.
Ranging from low weeds to large bushes the nightshades all have one thing in common – they are definitely not for eating. Of interest is the fact that, while we are likely to refer to the small varieties as ‘deadly nightshade’, that is actually a whole different species (Atropa bella-donna) which is extremely rare in New Zealand.
There are two native nightshades (Solanum aviculare and Solanum laciniatum) both known by their Maori name of ‘poroporo’. Tall and spreading bushes with long and heavily veined and hairless dark green leaves, green or purplish stems, trumpet shaped mauve flowers with yellow centres, and drooping single oval green berries which turn orange as they ripen.
Famously known as the poison which killed Socrates, hemlock is alive and living in New Zealand, and is still capable of causing death or at least birth defects in pregnant animals which eat the foliage. . Regarded as a noxious weed in many parts of NZ, if it appears on or around your land, it would pay to check its status with your local regional council.
Everyone needs to do their bit to control wild ginger. The name wild ginger is applied to two species. The most common and most invasive of the two is the seed bearing kahili ginger, with the non-seeding yellow ginger being less common and also less invasive.
A weed that belongs to the brassica family, creeping yellow cress is found in cultivated ground, damp pasture and river beds.
Hedge mustard is a sneaky weed. Initially it grows as a flattish rosette, and may, to the uninitiated, look like a dandelion. But the indentations (or teeth) in the leaves go right to the stem with a slight gap between each, and the stems themselves turn purple from the centre outwards.
Famously known as the poison which killed Socrates, hemlock is alive and living in New Zealand, and is still capable of causing death or at least birth defects in pregnant animals which eat the foliage.
When is a weed not a weed? Well possibly when it’s a plantain. The Saxons recorded the broad leafed variety as one of the nine sacred herbs, and migrants through the ages have taken it with them to other countries, so that in countries like New Zealand and America it has often been called ‘Englishman’s foot’.
Are you wanting to identify an unknown weed, but not sure where to start? Here are some useful information sources:
Do you remember seeing photos of brides from the 1930s each clutching a huge and unwieldy spray of what are commonly called arum lilies? They grew so well in New Zealand that they could be found in most gardens some years ago.
But like so many introduced plants from other parts of the world moderation was left behind in the host country, and they took off here like weeds in any damp places they could find, including pasture, particularly in the northern North Island.
Do you remember seeing photos of brides from the 1930s each clutching a huge and unwieldy spray of what are commonly called arum lilies? They grew so well in New Zealand that they could be found in most gardens some years ago.
Cleavers is that maddening hairy/clingy weed which appears everywhere in early summer and climbs through, round and over grasses and low shrubs, trying to smother everything. Sometimes mistakenly called bidibidi (which is a NZ native with much larger hooked spheres as seedpods), the seeds, stems and round seed pods catch and cling to clothing and animal hair.
Thistles were already a problem in New Zealand by the 1850s. They were probably introduced accidentally by early farmers in seed mixtures, and are now a nation-wide problem. There are over a dozen species of thistles in New Zealand,
Despite their alarming names these are two rather inoffensive weeds, more often found in gardens and crops rather than pasture as they prefer loose, fertile soils.
Although they have different scientific names they are both members of the Lamiaceae, and to the unitiated eye they can appear identical.
These days, with the heavy emphasis on achieving maximum production from our pastures, the ‘preferred’ species are perennial ryegrasses and white clover. Yorkshire Fog (or velvet grass as it is known in the US) is generally regarded as a ‘nuisance’ grass, almost classified as a weed.
“Write about fireweed” said a friend, “I’ve got it growing all over the place”. But ’fireweed’ is one of those all-embracing terms which attaches itself to different plants in different places. And all these plants have one thing in common – they are the first to colonise soils exposed by forest fires or forest clearing.
The paddock and roadside nasties are taking advantage of the advance of more spring like weather, and the base rosettes of several types of thistle are already appearing, particularly in bare spots. So now is the time to attack before they shoot upwards.
Despite their alarming names these are two rather inoffensive weeds, more often found in gardens and crops rather than pasture as they prefer loose, fertile soils.
Although they have different scientific names they are both members of the Lamiaceae, and to the unitiated eye they can appear identical.
Oxeye daisy is a perennial weed commonly found in poor and wetter pastures – especially where there is pugging and is common on dairy pasture sidelings in the Waikato.
Barley grass is one of nature’s survivors. Not only does it grow where and when other grasses fail to thrive, but it has developed a flexible seeding technique which allows it to grow unnoticed until the day length, temperature and soil moisture level is suitable for seedhead development and dispersal.