Lawn diseases are either a pathogen or mycelium. If the fungus is not correctly identified and treated it will spread and can damage your entire lawn. An accurate diagnosis is essential to ensure the correct lawn fungicide is applied.
The most common lawn diseases are:
Red Thread
Red Thread has become a common disease on lawns, particularly those with poor light, and soil. Red Thread can also occur after periods of heavy rain during which plant available nitrogen is washed from the soil. Red Thread is particularly able to affect the Red Fescue grass types. Annual Meadow grass and Bent grasses are also prone.
The symptoms are usually seen during late summer when sporadic reddish patches of dying grass appear. It may be on closer inspection red needle like threads can be found growing on the grass leaves.
The red needles are stromata which can exist in a soil for up to 2 years before germinating. They enter the leaf by the stomata which become the point of infection. Red Thread is more of a leaf disease so is unlikely to kill the root system. Therefore turf can recover adequately given time.
TruGreen® Lawn Care Specialists can take preventative and curative action to reduce the effects of Red Thread to your lawn.
Rust
There are lots of different rust diseases in horticulture some which affect turf grasses. The more susceptible grass species are Perennial Ryegrasses and Smooth Stalked Meadow grasses.
The most common time of year for infection to occur is early summer through to the late part of autumn. As with other turf diseases, humidity, low fertility and infrequent mowing regimes are common causes.
The infected grass appears rust coloured due to the production of copious yellow and orange spores on the leaf surface.
Reduced incidence and control can be achieved through adequate fertility, regular mowing and if necessary the use of a plant protection product.
Fusarium / Microdochium Patch / Pink Snow Mould
Fusarium is a turf disease that is caused by a fungus called Microdochium nivale. It is often found in fine turf situations, such as bowling greens, but can appear on lawns, particularly after prolonged snow cover. In such instances it may be known as Pink Snow Mould.
Good soil fertility is the key. High levels of nitrogen can increase incidence and this is one reason that TruGreen® lawn care specialists use autumn/winter fertilisers containing low quantities of nitrogen in the spring and autumn periods.
The conditions during which the disease is most vigorous are high humidity, surface wetness (rain, dew, poorly timed and frequent irrigation) alongside cool temperature.
Disease symptoms can appear as small circular patches which first appear as water-soaked spots under 5cm across. Grass colour will change to orange – brown, moving on to a darker red-brown which sooner or later becomes a tan / straw colour. If the disease goes unnoticed it can start to spread in lines because spores can be spread by mowing. Spots of Fusarium often merge to form larger areas of disfigurement.
After snow cover, the fluffy white mycelium fungus can be found on matted grass leaves and the affected grass looks straw coloured with a pink tinge. Fusarium survives over the summer months because it rests on grass debris such as grass thatch. When favourable conditions return, the pathogen will infect leaves of living plants. Under wet, cool conditions, it will spread quickly due to the large numbers of conidia spores. Conida spores are produced asexually which means uniformity and large numbers being produced. These spores will be spread be mowers, feet and wheeled equipment.
There are several factors that can make it easier to predict the likelihood of incidence.
- Humid atmosphere, shade and wetness when accompanied by cool temperatures
- Inadequate circulation of air above the grass sward
- Rapid, forced, weak top growth in spring / autumn
- Alkaline soil pH, 7 – 14
- Weak turf, perhaps due to wear or irregular mowing
- Blunt mower blades causing a poor cut
- Compacted soil. and poor drainage.
Outbreaks can be reduced by a number of means:
- The practise of cultural control methods such as aeration and scarification
- Regular mowing
- Alternating the direction of the cut helps the grass stand upright this will also help air move between the plants
- Lowering nitrogen applications at the end of the summer / early autumn period
- For the most enthusiastic gardeners, they can play a role by removing dew with a rake in the mornings.
Leaf Spot
Leaf Spot appears on the leaves of some grass plants. The species most likely to be attacked are Smooth Stalked Meadow grass and Ryegrass.
Leaf spot occurs in the summer months when temperatures are high and conditions are humid. Minor infection may result in lesions on the leafs. The infected area is normally brown in colour, as the infection progresses the colour in the surrounding tissues changes. As with other turf diseases the leaf tends to turn a pale brown or tan colour. If the infection moves down to the leaf sheath it will die resulting in thin strands of grass. In advanced stages where many plants die in large patches it is known as ‘melting out’.
Leaf Spot is the common name given to a large number of lawn diseases caused by the same family of fungi. Several fungi may be responsible but it is thought that Dreshlera is the most likely.
If your lawn has been infected with Leaf Spot contact your local TruGreen® Lawn Care Specialist.
Dollar Spot
Dollar Spot is a disease that affects Red Fescue grasses after mild and wet weather in early autumn.
The leaf can be said to have an hourglass appearance. The waist of the hourglass is the pale brown infected area of the leaf and the wider part is not yet affected. Retaining its original dimensions and appearing to still be health and green. The dying and healthy tissue are separated by the stroma which is red/brown in colour. This fungus rarely produces spores.
The grass roots are not affected and so natural recovery is possible, particularly if adequate fertility is maintained. This is also one method of preventing the outbreak in the first place.
If Dollar Spot is an issue in your lawn contact your local TruGreen(R) Lawn Care Specialist who will treat the lawn disease with the appropriate plant protection products.
Fairy Rings
Fairy Rings can be common on lawns and rough grass areas generally appearing more or less in circles. There are three types:
Fairy Rings – Type 1
These can be identified as a ring of dead turf bordered on the inner and outer edges by fast growing, deep green, healthy looking grass.
This damage occurs because Mycelium on the inside of the ring, drains the nutrients present in the soil, then dies and produces an impermeable surface. The soil is depleted of nutritional content and water starving, the grass plants.
Fairy Rings – Type 2
Fairy Rings are visible as very dark circles of healthy looking grass. It is rare that excessive damage is caused to the turf but, the presence of fairy rings spoil the uniform look of the lawn.
The ring of enhanced growth is probably due to the release of nitrogenous compounds cause by fungal breakdown of organic matter.
Fairy Rings – Type 3
These have no noticeable effect on the growth of grass itself, but mushrooms and toadstools grow on the surface. These normally appear in the autumn.
Picking the mushrooms and toadstools before mowing helps prevent the spread of the fruiting bodies.
Your local TruGreen® lawn care specialist can help by using an Integrated Disease Management Programme (IDM) to remove your fairy ring problem.
A lawn care maintenance programme can help prevent lawn fungus.
- Most fungal diseases use the moisture on the leaves of grass plants to produce and move spores. Avoid watering just before dark as water will remain on the leaf blades longer at night.
- Mowing less frequently during humid hot weather reduces stress on the grass plants and minimises the possible transfer of grass diseases.
- The way you mow affects your lawns ability to resist diseases. Mowing too low increases the chances of scalping. Cutting your grass extremely short is very stressful to the plant and leaves it susceptible to lawn diseases.
- Blunt or dull mower blades shred the tops of the grass leaves, and expose tissue for lawn diseases to enter the plants easily.
- Often, lawn diseases are specific to certain varieties of grass and one approach may be to introduce other varieties of grass into your lawn.
- Increase light, air access and movement over the grass by pruning overhanging trees and shrubs, will all help reduce incidences of turf disease.
- Lawn aeration also helps produce healthy grass.
Implementing the above good practices will help reduce the likelihood of a lawn disease. These techniques along with the potential use of a fungicide will help reduce incidence as part of a Integrated Disease Managment Plan. A professional fungicide may have to be applied to control the most damaging lawn diseases. These products are not available in DIY stores.
What is a turf disease?
There are a number of turf diseases that are common in the UK. The development of most diseases is usually dependant upon weather conditions, so recent weather conditions are considered during any diagnosis. Most diseases will have certain characteristics such as discolouration of the grasses, brown dry patches or signs of fungi (mushroom type growth).
Why do you need to treat turf diseases?
It is vital that all turf related diseases are treated as soon as possible as the more virulent diseases will kill the grass plant (leaf/root or both). Ideally the best form of treatment is by preventative measures rather than by reactive measures. Most lawns will suffer from disease at some point of the year and you are recommended to have a pesticide treatment within any turf maintenance programme.
Benefits of disease treatment
- Healthy grass/Leaf and root structure
- Uniform dark green grass
When and how to treat turf diseases?
Pesticides can be applied throughout the year apart from when the ground is frozen or waterlogged. If you are adopting preventative measures then you are advised in having treatments during the early summer and late autumn period. The more regular the applications the better the control. You can also reduce the chance of diseases by adopting good cultural methods such as regular scarification to minimise any thatch layer, and aeration to allow for a good air flow to be maintained to the root of the plant.
When can you treat turf diseases
- 12 months of the year. (Apart from when the ground is frozen or waterlogged)
- Summer/Late autumn. (Preventative measures)
For the treatment of all turf diseases choose TruGreen?
- By visiting your lawn regularly, we can identify problems whilst they are still small and treat them before they cause serious damage.
- Our extensive experience has shown that a lawn thrives with multiple feedings – because we’re there regularly, we can customise the treatments to the needs of your lawn each time we visit.
- With 35 years experience, we’re also the world’ largest lawncare company.
- Our professional technicians are licensed to provide weed and moss control, lawn fertilisation, aeration, scarification and disease treatments plus much, much more.
Turn your lawn into a stripy success no matter what condition your lawn is in, we can work towards getting it back into shape so that you can enjoy it. Why not give TruGreen a call today on 0845 201 1187 or find your local TruGreen business.
