Why are certain weeds better at adapting to growing in lawns than others? The answer is simple; they can survive the constant mowing by keeping most of their leaves below the mower's blades.
If you imagine your lawn as a competition between the grass and the weeds both competing for space, nutrients and water. In creating a lawn you should aim to create conditions in which the grass plants have the competitive edge, the upper hand. This can be achieved by using the following methods:
Weed killers - both systemic and contact. Two types of weed killer are available, the simplest is the contact type used as a general weed killer and especially useful for the control of moss, Normally called a lawn sand it is a mixture of iron sulphate, nitrate sulphate and sand to bulk up the material. It works by burning the weeds. This is possible because weed plants such as daisies are often broad-leaved; the lawn sand once spread sits on the leaves burning them to death. The grass leaves are normally thin and upright so that the lawn sand bounces off during spreading and does not burn. The systemic type weed killers works because weeds and grass plants are from two different plant groups, monocotes and dicotes. In simple terms the chemical contained in the weed killer acts on the chemical growth clock in the plant and causes the plant to outgrow itself to the point it can no longer sustain growth and dies.
The two different types of plant (monocte and dicote) have different growth clocks and so it is possible to kill the dicotes (weeds), with out killing the monocotes the grass plants.The key to using a weed killer is to make sure the weeds have enough leaf growth. This is achieved by not cutting the grass several days before, and make sure the weed plants are growing and not dormant at the time of spraying.
Soil pH control - control of soil pH can help to control weeds. This is because most lawn weeds grow best at a pH around 6.5 and the finer lawn grasses grow best at a slightly lower, more acid pH at around pH 6. The lower pH normally accrues in the course of normal feeding with high nitrogen feeds.
Watering programmes - by adopting a watering program that soaks the lawn once a week rather than watering the lawn lightly every day during the summer. It is possible to encourage deeper grass rooting and limit the availability of water to the shallow rooted weed seedlings.
Feeding - It is important to feed you lawn in small quantities "little and often" as this helps restore the nutrient that have been removed by cutting. If the grass becomes weak from lack of nutrients this creates a thinner grass cover and allows weeds to establish themselves.
Scarifying - light scarification through the spring and early summer helps to remove the existing weeds from the lawn.
Mowing and removing the clippings - helps to control weeds by removing the growing tips to stopping them from spreading. (Take a look at our Grass Cutting Service)
