My lawn is overrun with weeds – what can I do?

If the grass is always greener on the other side of your fence, plant agriculture professor Katerina Serlemitsos Jordan has tips to help you grow your own healthy lawn.

An avid golfer, she has a PhD in turf pathology and now works with golf courses, athletic fields and sod farms to diagnose and treat lawn problems.

Weeds are among the biggest enemies of a healthy lawn, taking advantage of weaknesses such as poor soil and lack of nutrients. Lawns face a constant barrage of weed seeds from the air — one dandelion can produce more than 2,000 parachute-equipped seeds per year.

The same conditions that are bad for grass are ideal for weeds: lack of fertilizer, aeration and water. “I would say 80 to 90 per cent of the time that we see a really weedy lawn, it’s because that lawn hasn’t been looked after.”

Nitrogen is key to a healthy lawn, so choose a fertilizer that contains this nutrient.

But fertilizer alone won’t help a lawn that is more than half weeds. That’s when a lawn needs intensive care. Serlemitsos Jordan recommends removing as many weeds as possible by hand and filling each hole with topsoil, grass seeds and fertilizer to prevent weeds from returning. “Even if you get to half of them, it gives your grass a fighting chance.”

For those who prefer chemical warfare, she recommends hiring a lawn care company to apply an approved herbicide.

Another common mistake that homeowners make is letting their lawn grow too long and then cutting it too short. Removing more than one-third of the grass blade stresses the plant, so mow more often and cut off less. Make sure your blades are sharp, since a clean cut heals better and retains moisture.

Tips to make your lawn healthier:

1: Feed your lawn with a slow-release fertilizer with nitrogen.
2: Aerate your lawn in the fall to reduce compaction and allow oxygen into the soil.
3: Plant hardier grass species like fescue.