Many people don't realise it, but the more frequent snowfalls and lower temperatures this winter can be particularly conducive to certain fungal infections that can spoil our beloved lawns. Here are two diseases we would like to highlight.
Disease 1
Snowdrop (Microdochium nivalis)
In our climate, it can appear as early as autumn, but it most often spreads over large areas in the early spring after the snow has melted. As its name suggests, it is particularly fond of moist, humid, cool environments with temperatures below 10°C. If the snowfall is followed by a sunny period, these conditions are already established, as the ground under the snow is already warming and evaporation and respiration are initiated, but the snow cover is blocking airflow. The nitrogen fertilisation in autumn is a predisposing factor. This causes plant tissue to loosen, making it easier for the pathogen to infect plants.
Snowdrops (Wikimedia)
Symptoms: a whitish-greyish-reddish coating appears on the leaf, in the active zone of infection, small oval circles are observed, which grow to around 30 cm and then merge.
Disease 2
Dollar spot (Typhula species)
(Peter Landschoot)
A true winter disease, the infection often spreads under the snow cover and it is only after the snow has melted that we notice the large grey patches where the plant has withered. In infested lawns, orange spots the size of pinheads appear in spring. Unlike snowdrops, infested patches usually do not die and regenerate in the spring when the warm weather arrives.
Typhula incarnata sclerotia (Peter Landschoot)
What do we recommend against winter diseases of the lawn?
Spray/water Tricho Immunnal in autumn, spring at 50g/10l. The autumn application has a preventive role, while the spring application is used for fire-fighting and regeneration. Spraying should be carried out in sunny conditions with temperatures above freezing. Always cut the lawn beforehand, so that the beneficial fungus can easily penetrate the wounded areas.
Remove clippings and leaves from the lawn. Use decomposing bacteria to eliminate turf matting or ensure that the lawn is aerated every six months/year.
It used to be a common practice in agriculture to go out with various machines and break the bark on the fields of frozen snow-covered fields of cereals. However, according to most reports, this did more harm than good. Indeed, frozen leaves break very easily, creating a scarring surface. We also avoid trampling frozen grass.
Increase potassium in autumn and abandon nitrogen fertilisation in late autumn. Aid spring regeneration Asco Alga and BlackJak 1-1dl/10l with a spray mixture, especially for dollar spotting.
Remember, it's not enough to feed the plants, you also need to feed the soil! Healthy soil life leads to healthy plants.
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