Humidity and your Lawn

Humidity can affect more than your ability to sleep at night and the frizziness of your hair, it can cause issues for your lawn too.

 

High humidity levels, especially like those that South East Queensland is facing at the moment from large rainfall totals, can lead to disease problems for your lawn. Humidity and heavy dews ensure that the leaves remain moist, which offers the perfect breeding ground for fungal diseases.

 

Fungal diseases originate from spores which require moisture and warmth for germination. Queensland’s humid, sub-tropical climate provides both.

 

Unfortunately, there is not much that can be done to alleviate the humidity affecting your lawn, other than to avoid additional watering and to increase air-flow where possible to aid in the drying out of excess moisture. Turn off automatic watering systems and don’t water in the evenings when there is not enough sunlight or time before nightfall to dry the leaves of the grass plants. Cut back overhanging branches so that more sunlight and air reach the leaves.

 

Different varieties of turf grasses in South East Queensland are susceptible to different types of fungal diseases.

 

Grass VarietiesFungal Diseases
Queensland Blue CouchDollar Spot
KikuyuFloral Smut & Spring Dead Spot
Broadleaf Carpet GrassSpring Dead Spot
Soft Leaf Buffalo GrassSpring Dead Spot

 

Fungal disease types can be difficult to determine, but fungal diseases attack only a distinct grass species.

 

As always, prevention is better than a cure. Before an expected period of high humidity apply a fertiliser with nitrogen and potassium, it will give the lawn a boost and increase its defences against a fungal disease attack.

 

If a fungal disease does take hold, you should take steps to make sure it doesn’t spread. Avoid walking over the area and thoroughly clean any garden tools used on the affected area, but try not to worry about it too much. Plant disease expert Dr. Cynthis Westcoot, ‘ In my experience, gardeners and insects, to say nothing of dogs, are more harmful than fungi to the average lawn’.

 

Most fungal diseases will die off once the humidity levels drop or the season changes, however fungicides are available if deemed necessary for the immediate health of the lawn. Seek professional advice on the best product for your lawn variety and always use only as directed.

 

If your lawn is persistently plagued by fungal disease then it may be time to change to a more resistant variety of turf. Sir Walter soft-leaf buffalo is pest and disease tolerant and available now from Daleys Turf. You can also subscribe to Your Free Lawn, Garden and Landscapes eZine at www.daleysturf.com.au; to get ideas and tips straight to your inbox on a monthly basis.

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