The conditions that can cause a moss problem includes loads of shade,poor drainage,acidic soil,too much water and compacted soil or any of the above in combination. I struggled with the moss before and it was not a happy ending. Now three years later it has grown to epic proportions and is quite noticeable in my lawn. It is really not too good for healthy growing grass.
The best control is no doubt with chemicals which I utlilized in this case because the moss was too far along. However there are "cultural" means by sowing more shade tolerant grass and keeping the lawn in a shady area mowed to the correct height to encourage deep roots. There is the alternative by planting ground cover forgetting the grass altogether. In a drastic move, you can eliminate shrubs and trees in the area to allow more sunshine.
However once you are in the crisis mode it is time to bring on the ferrous sulfate monohydrate sold under various brand names. After application the moss will turn black and supposely vanish from your lawn. This depends on the method of applying. I found with the granular brand that it was best to apply with a bucket and garden shovel by hand. You leave one or two small sprigs of moss and it is off to the races. It must be moist after application and the one brand does help with a feeder nozzle. The application by hand works best but a word of caution please use gloves and do not spread on a windy day.
The area may need to be raked as the blacken moss does not always vanish. It is definitely true if the moss was thick. The pH of the soil must be changed to a factor of 5.8 to 6.5 since the moss enjoy that acidic soil. This can be accomplished by use of a agricultural or dolomitic lime. It does little good to apply this before you are rid of the moss. You may have your pH checked by purchase of a kit from your local nursery or contacting your cooperative extension.
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