Dear Anne,
“My lawn has suddenly turned into a huge patch of moss and white clovers after all this hot weather? I have completely no grass left. What’s the secret to having a green, nice looking lawn? Also how can I level my lawn and reseed it so I get even coverage. How can I stop the seed from washing away?â€
Sandy Lai, Belcarra
It’s most likely the grass on your lawn has gone dormant from drought. But when this happens, the grass roots are only dormant. When we get regular rain this fall, you may find your grass growing again and greening-up.
In future, if you always mow with a long cut (so the grass is about 3†or 7 centimetres tall), you may find your lawn suddenly looks a lot better.
Setting the lawnmower for a high cut is an important key to having a nice, green lawn.
When the grass is taller, there’s more surface to each grass leaf. This means it’s better able to feed itself through photosynthesis – and among longer grass, moss and clover will be largely hidden.
So there’s a possibility that if you wait for fall rains, you may not be forced into major lawn work.
I suspect your moss is thriving where the clover is weak and the clover is doing well where the moss is weak. Moss grows best in shade, while clover loves sun.
Dolomite lime sprinkled on lawns will kill moss and feed your lawn as well. But moss can’t be permanently removed anywhere a lawn is very shady. In partial shade, the moss is weak and a healthy lawn of grass easily out-competes it.
It’s best not to try to remove the clover. It has very deep roots and is resistant to weed-killers. More importantly, clover is such a good natural fertilizer for grass that many grass seed mixes deliberately include clover seed. Clover is a nitrogen-fixer that transfers nitrogen from the air and stores it on its roots where grass feeds on it.
If your lawn really does need work, this should be done this fall when nature provides the moisture for grass seed to grow.
The lawn soil is probably compacted and bringing in a machine to aerate it would add oxygen to the soil and discourage voles which make tunnels under lawns. Voles, and to some degree moles, are a major cause of uneven lawns. Their sub-surface excavations gradually collapse the soil in some places and not in others.
Grading machines can level lawns quickly and efficiently. But this is no substitute for aeration which boosts the supply of oxygen to plant roots.
An alternative to machine aeration is plunging a garden fork into the lawn about 12†(30 cm) apart all over.
The next step is bringing topsoil in. Try to rake it evenly all over.
When you seed, try scattering the seed in parallel lines all over the lawn, then scatter it again in parallel lines going across your original lines.
When it’s all sown, the seed won’t wash significantly if you cover it lightly with straw. This also helps keep it safe from birds. But try to get straw that contains little or no weed seed.