Grass Clippings
Unseasonal seasons
We have now past mid- October, and it is extraordinary to report that we still haven’t had a frost yet in SW15. What is more, the weather-prediction this week is that we could see the mercury rising up to 18 degrees before the weekend. For those who still haven’t turned on the heating, this is good news. But it will have consequences for the natural environment somewhere down the line.
Since August, when the rains that helped relieve some of the stress from the turf and aided recovery, many tree species have started to put on new leaves around the course, especially on the older oaks. Acorns almost look like they are on steroids this year – the heat stress has supersized them and there is a bumper crop out there to ensure the continuation of the species.
What is alarming is the re-flowering of the horse chestnut trees in September which isn’t a good sign for how they will cope with the autumn. This second flowering has been recorded as an event in past decades when high summer temperatures have made the first set of leaves wither and deplete. The tree will put more energy into producing more leaves and subsequentially flowers in an attempt to keep photosynthesising while there is adequate day length. This can cause issues once the frosts arrive as it can further stress the tree, as the leaves will eventually be prone to frost damage if there is a prolonged cold snap.
Other species such as birch and sorbus have shown heat stress damage from this summer’s long dry season for various anatomical reasons. Birch, for example, tend to have very shallow rooting which spread close to the surface. They are regarded as pioneer species, rapidly colonizing open ground especially in the process termed as ‘successional sequences’ in botany terms. Like sorbus, they tend not to enjoy warmer climes, as we have found so this year, there are a number of birch and sorbus which we are monitoring to see if they will make it through the winter and into the springtime.
Unusual visitors
We have had several unusual visitors to site in the last few weeks. Iain Tong from the greenkeeping section spied a young buzzard sitting on a tee yardage plate a few weeks ago. Possibly a good indicator that there is a good selection of smaller mammals for them to pick off. I have also seen a kestrel on the course in the last week which seem to be harassing some sparrows early one morning. Joe, our tree surgeon, was kept company in one of the older oaks by a mistle thrush on the course. Although the species is migratory, most resident birds will only hop short distances to over winter, hopefully we shall see them back here in the spring. As a gauge, sightings such as this are good omen that with more vegetation on the course, it is helping to create a habitat to support a diverse range of species for birdlife, mammals, and insects.
Leaf Season
Generally, Greenkeepers call this the Leaf Season, for good reason. October is when the workload changes from cutting grass frequently, to less regularly as the rate of growths slows – we are still waiting for the grass to slow down and by rule of thumb, I would hazard a guess that leaf fall is about two to three weeks later this year than normal. It is only in the last week that tree colour on site has started to change, and the first trees are starting to drop leaves. Each species normally has a specific time for leaf drop. Horse Chestnuts are usually the first, followed by London Planes and so on until in February the Oaks and Beech finally surrender their vail of brown leaflets. The trigger for autumn colour to develop is a combination of day length and night temperature.
As days shorten, the amount of sugar generated by photosynthesis drops off, and hormones in the plant trigger the leaf sealing and shedding process. This is accelerated by cooler nights, but the lower temperatures also act on the compounds remaining in the leaf, breaking them down more quickly. A warm dry ‘Indian summer’ followed by colder nights is the best combination, keeping the leaves working later and then shortening the leaf drop process. That way, more compounds remain in the leaf and there is less time for them to slowly break down to brown before the leaves drop. In a mild wet autumn, the whole process is much slower, so leaves are often completely brown before they fall and individual trees, and even single leaves, change colour at different times, reducing the whole spectacle. It is thought the red or purple anthocyanins either protect the leaf from cold temperatures or deter pests, such as aphids. The presence of these coloured compounds might allow the tree longer to reabsorb other valuable nutrients as temperatures drop in autumn, so they are left in the leaf to help that process.
Your garden
October is a great month for getting out in the good clear days and tackling the garden before the weather changes for the worse. There is always plenty to do at this time of the year and with an eye on the year coming, plenty to plan for the coming months.
♣ As previously mentioned, falling leaves are an annual problem this time of the year. Rake up fallen leaves from lawns, borders, driveways and paths, and store in bin bags to rot down into leaf mould.
♣ Apply an autumn lawn feed to revive the grass after the rigours of summer. Aim for a low nitrogen form of product with a higher potassium hit of this time of the year.
♣ Empty ceramic and glazed pots that aren’t frost proof and store in a shed over winter. If you have frost proof pots, ensure that they have feet placed under them, so the pots do not become waterlogged.
♣ Spike compacted lawns and brush with lawn sand or a light compost form. The more effort you can in put into a lawn, the more it shall improve in the following year.
♣ Fork up perennial weeds, including horsetail or bindweed, removing every bit of root.
♣ Collect up hoses and drip-feed systems and store indoors over winter, so they don’t freeze and split.
♣ Clean out and disinfect bird boxes, avian flu is causing havoc to bird populations at the moment so do your bit.