Doctor Greenfingers

Weeds

Common weeds found in the garden and methods of controlling & removing weeds.

Bamboo

To stop bamboo spreading uncontrollably, plant bamboo pieces for your screen or hedge in a trench lined on either side with sheet metal or hardboard. The barrier need not go deeper than about 45cm as bamboos are shallow rooted but may spread naturally by underground stems or rhizomes.

To eradicate bamboo that has got out of hand, cut the canes down to ground level, and spray them with a strong solution of glyphosate herbicide, such as Roundup or Zero. Any suckers which emerge later should be similarly treated, but be careful not to let the spray drift onto other plants.

To minimise problems with bamboo, choose varieties of bamboo that are clumping rather than spreading.

Solution

Yates Amitrole

A non-hormone, non-selective weedkiller. Amitrole controls most broadleaf weeds and grasses. However, its main use is for the control of the more difficult to control weeds including: Couch, Indian doab, Sheeps sorrel, Mercer grass, Periwinkle, Cape ivy, Wandering Jew, Wild onion, Docks and Bamboo.

Clover

Clover is a very common weed of lawns. Clover has leaves with three leaflets, and creeping stems that set roots at whatever point they touch the ground. Flowers are white or pink (Trifolium repens, Trifolium fragiferam). Clover, with white flowers, is a member of the pea family, Fabaceae. This means clovers can fix nitrogen from the air and therefore they favour poorly fertilised lawns. One method of preventing clovers from taking hold is to make sure your lawn is growing strongly and is well fertilised during the warmer, growing months.

Some home owners grow a complete lawn using clover. Never use selctive herbicides on clover lawns.

Solution

Yates Turfix

A selective, hormonal weedkiller and contains three active ingredients. Improved Turfix has no activity against grass species and can be used on a regular basis in spring and/or autumn to maintain weed-free lawns.

Dandelions

Dandelion is a perennial herb that has a very long tap root. The leaves are mid green and deeply divided. Flowers are yellow petalled heads not dissimilar to double daisies. After flowering the fluffy round seed heads appear.

Solution

Yates Turfix

Flat Broad Leaf Weeds

Marshmallow, dandelion, cat’s ear, lamb’s tongue, chickweed, plantain, fleabane and dock are some of the common broadleaf weeds found in lawns and home gardens. Broadleaf weeds usually have wide leaves that often hug the ground. Active growth varies between summer and winter weeds, and weeds which are perennials (weeds that don’t die after one growing season) and become dormant at certain times of the year. Examples of winter perennials are white clover and dandelion and examples of summer perennials are curly dock and plantain. The best time to control winter broadleaf weeds is in autumn and for summer broadleaf weeds is in spring. It is important to note that it is easier to control small, actively growing weeds than mature weeds that are starting to produce seed.

Hints: Mowing over these weeds stimulates their growth as it’s very similar to pruning your wanted plants. The use of sulphate of ammonia, or lawn foods which contain it, will discourage weeds, especially broadleaf weeds and clovers. Broad leaf weeds in lawns can be carefully spot sprayed with Zero Weedkiller.

Solution

Yates Hydrocotyle Killer

A selective weedkiller for the control of hydrocotyle, creeping oxalis and other broadleaf weeds (including daisies and clover) in grass lawns.

Ginger

Kahili ginger is a problem in warmer areas, especially in native forests where it often grows from pieces dumped by gardeners. Its seeds can also be spread by birds. Ginger is a perennial plant with fleshy green leaves that grows up to 2 metres tall. Flowers appear at the top of the stems in late summer and autumn, followed by the bird-attracting red seeds. The flowers have a delightful perfume.

Plant bases develop thick rhizomes that spread to smother native plants. The waxy leave are resistant to herbicide but good results can be obtained by applying herbicide to freshly cut stems. Remove dead flowers to prevent seed formation.

Solution

Yates Amitrole

Gorse

Gorse, a spiny shrub that was introduced from Europe, has made itself right at home in New Zealand. It produces yellow, pea-like flowers for months each year. These are followed by hairy seed pods that explode to release their seeds.

Gorse plants are very adaptable and will grow in a wide range of climates. Because they are leguminous plants, they have the ability to fix nitrogen from the atmosphere in the soil. Although high nitrogen levels in the soil helps gorse plants to flourish, they can be detrimental to many native plants. Treat individual gorse plants with herbicide and, once they’re dead, mulch the area heavily to prevent re-emergence of seedlings.

Solution

Zero Weedspray Concentrate

An effective, easy and economical way to kill weeds and grasses in rockeries, garden beds, paths, driveways, along fence-lines and lawn edges, or before planting new lawns and gardens.

Lantana

Lantana is a dense bush which scrambles over roadsides, nature reserves and neglected gardens, especially in areas close to the sea. The bush usually grows to about 2-4 metres wide, has square stems, with oval shaped leaves which give off an unpleasant smell when crushed. The flower heads are made up of about 20 smaller flowers ranging from white, cream, pink, purple, yellow and orange. Lantana spreads by layering, (roots form where branches touch the ground), and by seed, especially seed digested by animals.

Solution

Zero Weedspray Concentrate

An effective, easy and economical way to kill weeds and grasses in rockeries, garden beds, paths, driveways, along fence-lines and lawn edges, or before planting new lawns and gardens.

Moss, Algae, Lichen

Algae (a green or black scum) and moss are usually problems in shaded, over-wet or badly drained and compacted sections of the lawn and garden. If the soil is compacted, spike it with a garden fork to improve drainage, and if there is too much shade, cut back trees or shrubs to let in more sunlight. If the ground is too wet you may have to construct drains to take away the excess water. You can eradicate moss growing in lawns by applying twice weekly a solution of Yates Sulphate of Iron dissolved in water.

Trees which are lacking in vigour and already dying back, often have moss or lichens growing on the bark. It also can occur on healthy trees where the humidity is high. The moss or lichen itself does not actually affect the health of the tree as they are non-parasitic organisms. For lichen in trees, improve air circulation by pruning overcrowded branches and any overhanging growth from neighbouring plants. Improve plant health by watering, mulching and applying a fertiliser. Moss and Lichen can also be removed by spraying Yates Lime Sulphur very carefully to stems and branches or applying with a paint brush.

Solution

Yates Surrender

Controls moss, lichen, liverwort and algae in lawns, on roofs, cobblestones, tiles and other hard surfaces including terracotta pots.

Onehunga Weed

Onehunga weed is an annual weed which looks like a small ferny rosette about 20cm in diameter. Flowers are a tiny greenish-yellow. Seeds germinate in autumn but the Onehunga weed doesn’t put on much growth until spring. By the middle of spring each rosette of leaves contains a flowerhead with many spines. Seeds mature and drop from the plant by about the middle of summer. Onehunga seed is spread by foot traffic or on the fur of animals. The best time for control is when the plants are putting on their flush of growth during spring. When the seed heads have formed, uptake of herbicide is limited and control is usually not very successful.

Solution

Yates Turfix

Onion Weed

Onion weed is a proclaimed noxious weed for most of New Zealand. Onion weed is a perennial with thin green strappy leaves growing from a mainly white bulb which gives off an onion smell when crushed. Flowers grow at the top of a long stalk and are mainly white. Seeds form in summer and autumn and are spread mostly by wind blowing the seeds into new areas. Onion weed also develops small bulblets attached to the parent bulb. These sprout after the main parent bulb has died from herbicide such as Yates Amitrole or from breaking off when the weed is being pulled up. Therefore repeat applications onto the weed will probably be required.

Solution

Yates Amitrole

Oxalis

Creeping oxalis (Oxaliscorniculata) has tiny clover to heart shaped leaves, that form roots wherever the stems touch the ground. Creeping oxalis is a common weed of lawns and because the stems creep under lawn runners of buffalo, kikuyu and couch, it is hard to eradicate. Seeds are spread by movement of soil and water and lawn mowers.

Pink oxalis (Oxalis corymbosa) has large dark green heart shaped leaves and grows in clumps out of a small brown bulb. This plant begins its active growth in spring and mature plants have dozens of bulblets attached to the parent bulb.

Soursob (Oxalis pes-caprae) has clover-like leaves on unbranched stems and bright yellow flowers.

Heavy mulching will help to eliminate oxalis from garden beds.

Solution

Yates Hydrocotyle Killer

A selective weedkiller for the control of hydrocotyle, creeping oxalis and other broadleaf weeds (including daisies and clover) in grass lawns.

Paspalum

A tough perennial grass growing out from a central base or crown that is very difficult to pull out by hand when mature. Leaves are bluey-green and the seed spikes are usually seen in late summer. Where individual plants can be treated, this persistent weed can be eliminated with Zero. Paspalum in lawns can be removed by cutting off the clump at ground level with a sharp knife or hoe. Alternatively, apply Zero with a Zero Weed Brush.

Zero contains glyphosate, a non-selective herbicide which is ideal to control paspalum. The chemical is translocated from the above ground parts of the plant to the persistent root system. There is no residual action of glyphosate when it contacts the soil.

Solution

Zero Weedspray Concentrate

An effective, easy and economical way to kill weeds and grasses in rockeries, garden beds, paths, driveways, along fence-lines and lawn edges, or before planting new lawns and gardens.

Thistles

There are many varieties of thistle in New Zealand, of which Scotch Thistle was a declared a weed as far back as 1850. Thistles grow as a rosette of leaves close to the ground from which grow tall stems carrying the flowers. Flowers are mainly pink-purple although there are some yellow flowering thistles. Thistles leaves are pale green covered with hairs and spines. Thistles at the seedling or rosette stage are easily controlled by non-selective herbicides such as Zero Weedspray. During the winter months, thistles are dormant and herbicides are relatively ineffective (as herbicides rely on the weed being in active growth). Spring to autumn are the best times to control thistle. Spraying at early stages of growth is the most effective. Control of thistle at the flowering stage or later has much reduced success. For control of individual plants in garden beds, use manual methods such as hoeing, making sure to remove at least the top third of the tap root.

Solution

Yates Turfix