Lawn Broadleaf Weeds

Lawns are obviously less attractive with unsightly patches of weed and flowers, and can be difficult to walk on barefoot if species are present with prickles or which attract bees. Weeds can even create uneven surfaces in your lawn and lawn disease can turn a good lawn bad very quickly.

There are several weed species that thrive in NZ lawns, many look very similar to each other, yet vary considerably in their susceptibility to chemical control. Clearly the correct identification is vital before any treatment is applied. Our turf managers are trained to inspect, treat, and control lawn problems as they appear and once we get on top of things, our regular treatments will keep your lawn healthy & competitive and prevent lawn problems from coming back.

The following information provides a quick guide to broadleaf weeds that commonly affect NZ lawns.

Our Turf managers are trained to advise you of any other significant issues.
Catsear is often confused with dandelion, and certainly looks like it. Both are perennial weeds with rosettes and upright flower stems with yellow flowers and wind-blown pappus attached to the seeds. These species are often known as "flat-weeds." They are commonly found in turf and pastures. If Catsear is dominating in turf, it often suggests that nutrient levels are low, as Catsear is more tolerant of low fertility than many grass species.
As with most thistles, Scotch thistle has a tap-root. However, it is the only thistle species in New Zealand which has spines on the foliage both around the leaf margins and on the surface of the leaves. The rest only have spines around the margins. The foliage is a darker green than most other thistle species. The flower head is distinctive, being smaller than heads of nodding and variegated thistles, and larger than heads of Californian and winged thistles. As with all thistles, seed heads are a collection of florets, and each seed is attached to a pappus which allows it to be blown in the wind. Scotch Thistle is commonly found in lawns in NZ.
Dichondra is a perennial weed, spreading by slender creeping stems that root at the nodes. The kidney-shaped to nearly circular leaves grow alternate to each other, sometimes appearing whorled (a circular arrangement of three or more leaves) on the stems. Dichondra is cultivated as a ground cover in some lawns. Proper turf maintenance is the key to control of this weed - correct fertilisation, mowing and watering will encourage a thicker, healthier lawn and discourage Dichondra from growing.
Chickweed - annual mouse
Chickweed has bright, shiny leaves, distinctive hairy stems and small white flowers with deeply notched petals. It is a broadleaf weed that grows vigorously in cool, wet weather, forming a dense mat that crowd out desirable plants. There are a number of different chickweeds; the most common one of these is annual mouse-ear chickweed which is a real menace in turf. Its mat-like growth is commonly found in a wide variety of turf situations, especially in closely mown lawns. Unfortunately the seeds are often easily spread by birds and the wind.
Clover is a perennial weed that is low growing and found in most lawns. Farmers in NZ go to a lot of trouble to get clovers growing in their pastures; Green keepers go to as much trouble to remove them from turf. Some D.I.Y gardeners like white clover in their lawn but Green keepers generally try and remove it for a number of reasons including the patchy appearance they give turf and the prominent flowers they produce.If turf can be kept dense and competitive during autumn when the annual clovers are germinating, establishment of the seedlings is less likely to be successful.

Creeping oxalis1
Creeping Oxalis
Like many weeds that thrive in turf, creeping oxalis is a perennial weed and grows much like white clover, with a creeping stem which grows at ground level. The other distinguishing feature of creeping oxalis is the small yellow flower which forms over much of the year. Creeping oxalis is present throughout the year.

Onehunga weed
Onehunga Weed
Named after the locality in Auckland where this weed was first seen, Onehunga weed is a annual weed with a very small root system. The seeds are very distinctive with their sharp spines (prickles) which readily attach to bare feet(!) in summer. Onehunga weed is generally found throughout the North Island. It often invades in autumn in turf which has bare patches following hot dry summer. It produces seeds and dies the following spring – summer.
Dandelions are a broadleaf, perennial weed and do not die at the end of the growing season. Instead, they remain in the lawn (although they may become dormant and barely noticeable) and resurface again the following spring. Dandelions grow in any soil with foliage that stays below the level of mower blades, making them very successful weeds in turf. As a general rule this weed is easy to control, though repeat applications is recommended for the older more established plants with large root systems and woody stems.
The common daisy is a troublesome weed which is easily identified by its distinctive white daisy flowers and yellow centres. Daisies are commonly found in turf situations and although daisy can grow in a number of environments, it seems to prefer damp situations and does well where it is shady.
Although Docks are common weeds of pastures and garden areas they are seldom associated with turf because they are so large. However docks can adapt to mowing. The most common dock found in turf situations is “fiddle dock”. These grow as rosettes, with leaves branching out from a central growing point at ground level. The docks commonly found in turf tend to have a large root tap system too.
Docks do not successfully flower in turf, however docks can produce many thousands of seed per plant and these seeds can exist in soil for many years. As with most weeds though, dock cannot establish in turf is the grass is kept dense, lush and competitive.
Speedwells have quite small leaves and are often overlooked in turf. Creeping Speedwell is the most aggressive of these species and is considered a major weed in all turf situations. It is not known to produce seeds so presumably it is spread as fragments on people’s shoes or by lawn  mowers. Creeping speedwell produces a blue flower with small stalks. It is the most difficult broadleaf weed to completely eradicate from a lawn and is virtually impossible for the DIY gardener to treat it. Speedwells are tolerant to various turf weed controls but our regular, sequential treatments will get rid of it
Hyrdocotyle is a term used to describe a number different species, all of which are fairly similar to each other in look and their ability to cause major weed infestations in fine grass turf. The weed has become well established in NZ. Satisfactory control of hydrocotyle in grass is difficult for the DIY gardener to achieve because most off-the-shelf weed sprays will not kill it.

Fat-hen is one of the most troublesome annual weeds and grows best in fertile soils. Fat-hen was eaten as a vegetable until the 16th century when it was replaced in the diet by spinach and cabbage. It is very efficient at extracting nutrients from the soil. Fat-hen may act as a host to insect pests and it can also become infected with viruses easily. Some populations of fat-hen have developed resistance to certain widely used herbicides making it very difficult for the D-I-Y lawn gardener to treat and eradicate successfully.
Pearlwort is a small perennial weed commonly found in bowling greens and golf greens. It’s a bright green weed with tiny soft needle like leaves along slender stems. Although only a small weed it can form tufts as stems grow over each other. The small leaf size and the dense tufts can cause it to be confused with moss. Pearlwort thrives in lawns mown too low but is easily removed with chemical control.