Caring for your lawn in autumn
Check apples for ripeness and stored apples for rot
Anemone 'Prinz Heinrich'
Grass is a pretty amazing plant. Lawns provides us with a constantly green canvas from which to create the rest of the garden. Unless you have an absolute postage stamp of a garden then I like to see some lawn or grass in all gardens.
Battered and bruised as your lawn may be after a summers use it will recover and regenerate seemingly by magic, regardless of any tender loving care, to a reasonably healthy green surface. That just what grass does. But if you want to give it a helping hand and show it some appreciation now is the time to give your lawn an autumn make over.
For those of you with large lawns of half an acre or more grass management can become a real issue. The issue is one of cost, time and practicality. As a minimum annually you should try to keep your grass mown regularly, don't let it get longer than an inch and a half, control moss and weeds, and if possible give it a spring feed. I spring feed with a 7-6-17 agricultural fertiliser, because of cost, which works just fine for me.
If you are going to really love your lawn your first autumn job is to treat any moss that is there. This can be done on large lawns using sulphate of iron applied at a rate of 30 grams, a small handful per square metre. Treat only the effected areas and you will also need to treat the weeds with a selective lawn weed killer as well. On small lawns you can apply a pre mixed autumn weed, feed and moss killer that is available from garden centres. Don't use left over spring fertiliser as this is high in nitrogen and will induce too much new grass growth for this time of year.
Moss is most prevalent in shady, damp or compacted areas but to be honest in Irish conditions moss seems to grow nearly anywhere in grass. In really bad spots some surface drainage may help but shade is often unavoidable from buildings or overhanging trees. Both of these applications will blacken the moss which will need raking out but there is a product available called Mobacter which is a moss treatment with light fertiliser that provides a bacteria that eats away the moss creating no blackening or need for raking. It is expensive so only viable for smaller lawns.
When you have treated the lawn for moss and weeds wait for ten days. Next comes the job of scarifying which ideally should be carried out annually. Scarifiying is done to remove the dead moss but also to remove what is known as 'thatch' or dead grass cuttings and general fine matted debris that has accumulated over the summer. This allows air back into the grass at root level.
Scarifying can be done with a springbok rake, which is a good aerobic workout, or by hiring a scarifying machine which is suitable for large and small lawns alike. With the rake you can be quite brutal but with a scarifying machine be careful with the height adjustment so as to not go to deep into the grass roots which can cause quite serious damage to your lawn.
Aeration is the next job which can be done every two to three year. Aeration is particularly useful in areas of surface compaction to allow better drainage and here it might be carried out annually. In small gardens a garden fork or hand held aerating fork pushed into the ground its full depth at six inch gaps will work or again machines can be hired to do this job on larger areas. There are solid tine and hollow tine aerators. The hollow tine is designed to remove a plug of soil but unless your soil is light it will just block up the machine. On light soils you may only need to concentrate your efforts on areas of heavy traffic like play areas or washing line access. On heavy soils like with compacted areas annual aeration may help a lot with improving your lawn drainage.
Once areation is done a top dressing is brushed into the holes that have been created, do this with a stiff broom. A mix of one third sieved soil/compost/sand is generally recommended but on heavier soils half sand and half sieved soil and compost should be used. If gardening on very sandy soil you can leave out the sand component altogether.