Weeds

capedaisy chickweed couchgrass creepingspeedwell
Cape Daisy Chickweed Couchgrass Creeping Speedwell
daisy dock hawksbeard hydrocotle
Daisy Dock Hawksbeard Hydrocotle
onehunga paspalum pearlwort poaannua
Onehunga Paspalum Pearlwort Poa Annua
speedwell summergrass twincress yarrow
Speedwell Summer Grass Twincress Yarrow



Cape Daisy

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Cape Daisy (Arctotheca calendula) is also known as Cape Weed. As depicted in the photograph to the left, it has short thick horizontal stems with a rosette forming at the ends of these stems. As a result it forms thick, dense patches in lawns. The upper side of the leaves are green and the undersides are white. The characteristic flower is similar to a daisy in shape but it is pale yellow on the outer petals, bright yellow on the inner petal with a purplish centre.


Control

All lawn types: Cape daisy can be selectively controlled using Versatil, Banvine, Tordon Gold or Tordon Brushkiller. Be aware the fine fescue and NZ Browntop will discolour if Brushkiller is applied during the winter months. Therefore it is best to apply this product from September through until April at 20mls per 100m2 in 3 -5 litres of water. Fine turf species will also be affected if Brushkiller is applied to lawns that are suffering from heat stress or moisture stress. Therefore, the best control will occur if these species are sprayed prior to flowering and when the grass plants are actively growing. For that reason unless an alternative weed that needs Tordon Brushkiller to be applied for adequate control it is advisable to use one of the other suggested products. These are safer to use and the likelihood of damage to desirable plant species will be diminished




Chickweed

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There are a number of different types of weeds referred to as chickweed including chickweed (Stellaria media) and mouse eared chickweed (Ceratium glomeratum) Chickweed has long stems with rounded leaves placed as opposing pairs on the stem. The leaves are hairless as are the stems but the leaf stalks are hairy. Mouse eared chickweed is a bluish-green colour and has very hairy leaves and stems. In turf situations they tend to creep along the ground suffocating desirable plants. All chickweeds have small white flowers.


Control

It is more difficult to control than many broadleaf weeds as it is not susceptible to 2,4D or clopyralid. Tordon Brushkiller will exert the best level of selective control. Be aware the fine fescue and NZ Browntop will discolour if Brushkiller is applied during the winter months. Therefore it is best to apply this product from September through until April at 20mls per 100m2 in 3 -5 litres of water. Fine turf species will also be affected if Brushkiller is applied to lawns that are suffering from heat stress or moisture stress. Therefore, the best control will occur if these species are sprayed prior to flowering and when the grass plants are actively growing.




Couch Grass

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Cape Daisy (Arctotheca calendula) is also known as Cape Weed. As depicted in the photograph to the left, it has short thick horizontal stems with a rosette forming at the ends of these stems. As a result it forms thick, dense patches in lawns. The upper side of the leaves are green and the undersides are white. The characteristic flower is similar to a daisy in shape but it is pale yellow on the outer petals, bright yellow on the inner petal with a purplish centre.


Control

All turf types: The best measure of control for small infestations is to carefully lift long stolons from the sward and dip or paint on a 3:1 solution of roundup. The active ingredient will translocate through the remainder of the plant. This must be carried out when the plants are actively growing in summer. In the infestation is heavy then the lawn may need a complete spray with round up followed by replacement or re-seeding.

Fine Fescue: Gallant is registered to control couch in fine fescue lawns. The application rate is 37.5 - 50mls per 100m2. At the upper rate some damage may occur to the fescue and because of that we recommend that the lower rate is used as a spot spray treatment to the effected areas only. To ensure that grass is actively growing and healthy prior to treatment a nitrogenous fertilizer application (Turf Gold applied at 2.5kgs per 100m2)is recommended 10 -14 days prior to treatment. In dry weather conditions the lawn should also be irrigated for 7 -10 days prior to application. The best control will occur if the product is applied from November until March when the couch is actively growing.




Creeping Speedwell

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Creeping speedwell (Veronica filformis) is a perennial weed that has wide kidney shaped leaf and stems produces roots of their stems to enable them to creep along the ground to create a dense mat. The leaves are dark green and are lightly serrated or toothed. It produces light blue flowers on longish stalks


Control

All turf types: Creeping speedwell can be selectively controlled by using Axall. Tordon Brushkiller will provide a measure of control but this is only temporary. Because it is notoriously difficult to control, it is advisable to spray it or dig it out as soon as it is noticed. Tordon Brushkiller will exert a good level of selective control. Be aware the fine fescue and NZ Browntop will discolour if Brushkiller is applied during the winter months. Therefore it is best to apply this product from September through until April at 20mls per 100m2 in 3 -5 litres of water. Fine turf species will also be affected if Brushkiller is applied to lawns that are suffering from heat stress or moisture stress. Therefore, the best control will occur if these species are sprayed prior to flowering and when the grass plants are actively growing.




Daisy

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The common daisy (Bellis perennis) is a troublesome weed which is easily identified by the characteristic white flower with a yellow centre that is often used to make "daisy chains". It grows as a rosette and belongs to the asteraceae family.


Control

All lawn types: Daisy will be selectively controlled using Banvine, Versatil, or Tordon Gold applied at label rates.

Tordon Brushkiller will also exert a very good level of selective control. Be aware the fine fescue and NZ Browntop will discolour if Brushkiller is applied during the winter months. Therefore it is best to apply this product from September through until April at 20mls per 100m2 in 3 -5 litres of water. Fine turf species will also be affected if Brushkiller is applied to lawns that are suffering from heat stress or moisture stress. Therefore, the best control will occur if these species are sprayed prior to flowering and when the grass plants are actively growing. For that reason unless an alternative weed that needs Tordon Brushkiller to be applied for adequate control it is advisable to use one of the other suggested products. These are safer to use and the likelihood of damage to desirable plant species will be diminished.




Dock

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Dock or Rumex obtusifolius is a relatively common tap-rooted weed that in found throughout New Zealand, however because of its size it is not common on lawns. Closely related species such as fiddle dock (Rumex pulcher) and sheep's sorrel (Rumex acetosella) are likely to be more common in lawns. It has very large (up to 250mm long) wide, erect, round tipped leaved that are bright green in colouration.


Control

All turf types: Dock is controlled using a selective herbicide such as Tordon Gold or Banvine applied at label rates. It is preferable to apply these products form September until May when the plants are actively growing. Fine turf species will also be affected if these products are applied to lawns that are suffering from heat stress or moisture stress. In these circumstances it is advisable to apply fertilizer and irrigate for 7 ? 10 days prior to application to ensure that the lawn is in a healthy state prior to spraying.




Hawksbeard

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Many lawns become yellow over summer due to mass of yellow flowers appearing from weeds commonly referred to as dandelions. The term dandelion is often used to describe a number of different species. They are all members of the Asteraceae (Compositae) family, all grow as rosettes with tap-roots, have yellow flowers on long green stems, and all produce 'feathery' pappus with their seeds, allowing them to be blown around in the wind.


Control

The seedlings of these species are fairly susceptible to most herbicides commonly used in turf. However, because of the large tap-root systems that develop once these weeds get established, older plants are more difficult to control. We recommend using Versatill or Banvine.




Hydrocotle

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Hydrocotyle also known as Pennywort is a perennial and grows via stolons or rhizomes. It has small heavily serrated circular shaped leaves that are light green in colour. It has a distinctive odour when crushed that resembles cat's urine. It prefers moist, shady areas but will survive well in full sunshine. Some people even use it as the primary composition of their lawn however, it is not durable under heavy or constant wear situations.


Control

All lawns: Whilst most normal broadleaf weeds will burn the leaf of Hydrocotyle they will not provide long term control as the plants will recover rapidly. Tordon Brushkiller or other herbicides containing triclopyr or picloram will provide good control. However, this product should only be applied to fine turf species from spring through until mid-autumn when the grass plants are actively growing. Likewise these products should not be applied in hot dry conditions when the plants are under heat stress or moisture stress.




Onehunga

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Onehunga weed or Solvia sessilis is named after the suburb in Auckland where it was first found, though it actually originates form South America. It is most recognisable in the summer months by the spiny seeds commonly referred to as prickles that attach easily to bare feet. It is for this reason that most residential lawn owners wish to have it controlled. It generally germinates in autumn growing initially as rosettes and then producing short prostrate stems. The seeds form at the base of these leaves.


Control

All turf types: Onehunga weed can be selectively removed by using Versatil, Banvine or Tordon Gold. These products are best applied from July to September prior to seed set. Beyond this period the plants will be adequately controlled however the sharp seeds or prickles will already be present and as such will still be a problem to bare feet.

Onehunga weed often invades bare patches on lawns after hot dry summers. These areas should be scarified and re-sown in autumn to avoid colonisation by this weed species.




Paspalum

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Paspalum (Paspalum dilatatum) is a perennial grass weed that causes problems on lawns throughout the North Island of New Zealand. It is a problem in summer when it produces large numbers of seed heads and its low growing wide leaves hug the ground tending to smother other desirable species. It is dormant for the majority of winter, though the crowns are often still visible in lawns that are cut at a low mowing height. These seed heads are similar to some other types of annual summer grass, which tend to be prominent at the same time of the year. The leaves are dark green in colour and are hairless with the exception of two tufts the at emerge at the base of each leaf blade.


Control

Ryegrass lawns: Pasma or methylarsinic acid is effective if used in November or December. Be aware that Pasma will take out fine fescue grasses also. This is an arsenic based product and therefore it is highly poisonous. For that reason it is not recommended for residential lawns. It is a registered product and as such it can only be sold or applied by a registered user. Additionally, the registered user must have a Stage 2 applicators certificate.

The alternative solution is to spot spray the paspalum using Roundup or a similar Glyphosate product when the plants are actively growing and re-sow those areas in autumn.

Fescue lawns: Apply Gallant at 50mls per 100m2 when the paspalum is actively growing. Given that this is a high label rate, it is recommended that the Gallant is preferably used as a spot spray treatment otherwise some damage could occur to the lawn, particularly if the lawn is under heat or moisture stress.

Other Lawn types: Spot spray the paspalum using Roundup or a similar Glyphosate product when the plants are actively growing and re-sow those areas in autumn.If the paspalum infestation is heavy then we recommend spraying the entire lawn with roundup at 50mls/100m2 preferably twice 21 days apart to ensure an effective kill and then re-seed the lawn.




Pearlwort

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Pearlwort or (Sagina procumbens) is more accurately called procumbent pearlwort. It is a diminutive bright green coloured plant that has small needle shapes leaves set on opposite sides of a tiny stem. The pant looks similar to and is sometimes mistaken for Irish Moss. It forms a tight, dense mat even in closely mown swards.


Control

All turf types: Versatil is not effective however Pearlwort can be selectively controlled using Axall at recommended label rates.




Poa Annua

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Poa annua is annual grass weed from the large poa family that tends to act as an annual grass in irrigated situation. This species which is sometimes referred to as "annual winter" grass or "green-keepers curse" is endemic in soils throughout temperate parts of the world. It is a relatively small grass plant which is light green to yellow green in colouration and it seeds prolifically throughout the year. The seeds are white in colour and the leaf blades are soft and often crinkled when young. Poa annua is often confused with poa trivialis which is an annual weed. It seeds prolifically and will seed regardless of cutting height. It is probably the most common grass weed problem on lawns in New Zealand.


Control

Ryegrass, Tall fescue, N.Z. Browntop: Apply EXPO 500S at 40mls per 100m2. This will need to be applied twice within 14 days. It does act as a pre-germination spray and as such can be applied directly over freshly sown ryegrass seed to avoid poa annua infestations. Repeat applications will be required in 3-4 months time.

Fine Fescue lawns: Apply Gallant at label rates from September through until April. It is advisable not to use this product in winter as it tends to discolour the fescue.

Couch: Apply roundup at a 5% solution when the couch is growing rapidly.




Speedwell

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There are four types of speedwell all from the Veronica family. Creeping speedwell is dealt with under its own heading. (See accompanying photographs). The leaves are dark green slightly elongated with toothed margins. The flowers are blue, small and held on relatively small stalks.


Control

All turf types: Creeping speedwell is one of the more difficult to control broadleaf weed species but it can be selectively controlled by using Axall. Because it is notoriously difficult to control, it is advisable to spray it or dig it out as soon as it is noticed.

Tordon Brushkiller will provide a measure of control but this is only temporary.




Summer Grass

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Summergrass is a term used to describe a range of annual subtropical annual weeds that are endemic in soils in the top half of the North Island. They germinate as a function of light incidence at ground level once ground temperatures exceed 16o -17oC. Because of this they tend to cause most problems in spring or summer sown lawns in the first year after sowing. Being subtropical plants they grow very rapidly in warm humid conditions. This group of plants includes crowfoot grass (Eleucine indica) summer grass (Digiteria sanguinalis) smooth summer grass (Digiteria ischaemum). They are annual species and as such they will die and disappear from the sward in autumn when temperatures start to decrease. Quite often they can be mistaken for paspalum because the seed head is similar.


Control

Ryegrass Lawns: Apply EXPO 500 prior to the anticipated time of germination of these species. This product achieves a high level of success if used as a pre-germination spray. It can also be applied directly onto freshly sown ryegrass seed to prevent these species germinating.

Alternatively Pendamethalin can be used as a ?pre-germination spray. However, this is best used on mature swards over six (6) months of age. This product contains harsh solvents that tend burn ryegrass plants so it is best applied during or just prior to impending rain.

Fine Fescue lawns: Apply "Gallant" at 8mls per 100m2 when these species are actively growing.




Twin Cress

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Whenever new turf is sown, a large number of weeds often establish at the same time as the turf species. Many of these species are annual weeds which are seldom found in established turf. If they are not controlled by herbicides, they die out naturally anyway within the first year, being annual species, and then turf species usually prevent establishment of further plants.One of the most common weeds found in new turf is twin cress ( Coronopus didymus), and this is sometimes accompanied by a very similar species called wart cress( Coronopus squamatus). They belong to the Brassicaceae (Cruciferae) family.


Control

Although annuals like these species will die naturally within a year, they should probably be removed before this natural demise. As they are actively growing among establishing turf grass seedlings, the smothering effect of these rosettes may result in poor establishment and even death of some seedlings. By removinf teh weeds at an early stage, a more uniform and vigorous turf will hopefully be produced.




Yarrow

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Onehunga weed is a term that was once thought to encompass serveral different species, namely Soliva Valdiviana, Soliva Sessilis and Soliva Pterosperma. Taxonomists have recently decided however that these three species are actually just genetic variants of a single species, so these are now all considered to be Soliva sessilis.

Named after the Locality in Auckland where this weed was first noticed, Onehunga weed originally came from South Smerica. It belongs to the Asteraceae (Compositae) family, and in the vegetative state resembles a number of other turf weeds from this family, especially Yarrow ( Achillea millefolium) and soldier's button ( Cotula australis). Soldier's button originates from Australia and so is not native like the cotula species (which now belong to the Leptinella genus) used in bowling greens. Yarrow is found throughout the world and originates from Europe.


Control

The rhizome system of yarrow makes it particularly difficult to control, with regrowth often occuring from the rhizome following herbicide application. Even broad spectrum herbicides such as the 2,4-D/dicamba (Banvine) or Triclopyr/picloram (Tordon Brushkiller) mixtures may not completely control yarrow. However clopyralid (versatill) appears to be particularly effective on this species and so tends to be the preferred treatment for yarrow control in turf.