First aid for your lawn: fairy ring

Fairy rings are circles approximately one to 2.5 metres (three to eight feet) wide that consist of a dark green and fast-growing area of grass surrounding an inner area of partially dead or thin grass. They might contain mushrooms. Fix them with this guide.

• Fairy rings are caused by fungi that live in the soil.
• As the fungi feed on organic matter, they release nitrogen, causing the grass to turn dark green.
• As the colony grows, it disturbs the flow of needed water to the turf roots, creating thin or dead spots.
• Fairy rings often begin with the decomposition of organic matter, such as an old tree stump.

• By bringing up the colour in the rest of your lawn with a nitrogen fertilizer, you can mask much of the over-greening of the fairy ring.
• Hand-aerating the ring will break up the fungus and allow the flow of water and other nutrients to the grass roots.

• Generally fairy rings can be masked with the application of fertilizer, with results in 10 to 14 days.
• The grass within the ring will thicken up with aeration in about two to three weeks.

Aeration will help with fairy rings, but maintaining a healthy lawn with a balanced fertilization program is essential. Apply three doses:

1. Apply 200 grams per 28 square metres (half a pound per 300 square feet) in late April or early May to give the overwintering grass roots a bit of a boost.

2. Add no more than 200 grams per 28 square metres (half a pound per 300 square feet) at the end of June or in early July when temperatures are not at their peak. Stimulating growth during a heat wave will stress the plants.

3. Spread 500 grams per 28 square metres (one pound per 300 square feet) at the end of October. The best root growth takes place when the soil temps are between 15° and 18°C (60° and 65°F). The roots store energy over the winter, making the entire lawn healthier the following spring.