Every time I write about it being dry – it rains , I finished the following on Thursday 13th August and since then we have had 3.5 inches of rain !!!!!
Well the hot weather returned with a vengeance and lawns are really suffering as a consequence . The South East has been much drier than the western side of the country and even the rains of July have not helped.
Comparisons are being made with 1976 – also a long hot dry summer. In many places the ground is rock hard and rain when it comes is likely to run off and make very little difference – we will need steady light rains to make any difference.
We actually had 3 inches of rain in June and 2.5 inches in July – but the extreme temperatures of 24 deg C to 34 deg for weeks on end reduced the benefit of that rain.
Its been interesting looking at the soil profile of lawns that are dying back – the dark patches seen on the surface where grass is suffering are so dry penetrating with a soil auger is a real challenge . The core extracted is often completely bone dry to the point of nearly being dust, and at the surface 2-3 centimetres is a thick layer of dead matted material that acts as a surface sponge when it rains – but prevents water getting through.
Lawns that remain looking green and lush now are those that have the benefit of a good healthy soil and open structure – likely to be those that are relatively new where the soil was cultivated to a good depth and roots have been able to go down and soil capacity for holding moisture is good.
Healthy soils are vital to support grass – they need a lot of beneficial bacteria and fungi to be supporting the soil micro- organisms, good soil structure is important to this and extreme weather conditions wet or hot always highlight the problems.
Scarification and aeration is so important in these circumstance – although both can be very aggressive and so need to be done under the right conditions.
Aeration punches holes into the soil , to allow water to get through and oxygen which will encourage root growth. There are different types of aerator tines – some will slit the surface , others will spike or take a core of soil out . Soil type will determine the best tine for the job – it should not be carried out on soils when too wet, ideally it is done when soils are dry , this can have the added benefit of shattering encouraging further cracks to appear in the soil around the tine . However aeration cannot be carried out when very dry – as the machinery will be unable to penetrate the soil as is the case now .
Now is the time to carry out work to improve soil structure – and through September , please don’t hesitate to call for a survey to look at the soil structure of your lawn.