What should I track in a lawn care log?

The date and task every time. For fertilizer: product, N-P-K and kilograms. For mowing: cutting height. For seeding: seed mix and rate. Aeration, lime and soil test results when they happen, and cost if you want to know what the lawn costs per year.

Why track when I last fertilized?

Because a second application too soon burns grass, and a missed fall feeding costs you next spring. Six weeks between applications is a good rule, three weeks the minimum.

How often should I test soil pH?

Every two to three years for most lawns, or yearly if you are adding lime. Kentucky bluegrass does best around pH 6 to 7. Log each result so you can see whether a treatment worked.

Is a lawn app better than a notebook?

A notebook works if you use it. An app does the math: weeks since the last feeding, money spent, and whether the weather suits the next job.

Lawn Care Log: What to Track Through a Canadian Season

A Canadian lawn season is short. Between the snow melting and the ground freezing again, you get roughly six months, and the two feedings that matter most fall in the last three. That is exactly when people lose track of what they did back in May.

What should you track?

The date and task every time, plus what you need for the next decision:

Task	What to log	What you use it for
Fertilizer	Product, N-P-K, kilograms	When the next feeding is due, how much nitrogen went down
Mowing	Cutting height	Spotting whether you cut too short in July heat
Dethatching	Tines or blades	How hard the lawn was worked
Aeration	Date	Pairing it with overseeding next time
Seeding	Seed mix, rate	Which mix actually filled in
Lime and pH	Soil test result, kilograms of lime	Whether the pH moved

Fertilizer is the line that matters most. If your log says May 18, you know the lawn has gone all summer without food and the Labour Day feeding is due.

What a lawn care log looks like in the app

Here is the log for the example lawn in Toronto: a mow at 6.5 cm and 5.5 kg of lawn fertilizer on May 18.

Lawn log in the What a Green Lawn app showing a mow and a fertilizer application — The lawn log: mowed to 6.5 cm on September 13 and 5.5 kg of lawn fertilizer on May 18.

To add an entry you pick the task at the top: mow, fertilizer, lime, pH, seeding, scarify (dethatch), aerate, seaweed, wetting agent, iron sulphate and ground temp. For mowing you set the cutting height on a scale that shows how much grass you leave.

Log activity screen in the What a Green Lawn app with a 6.5 cm cut height — Log activity: choose the task and date, then set the cut height. Cost and notes are optional.

What does the app do with your log?

In the app the log feeds straight into the advice:

Weeks since the last feeding shows on the Fertilizer Score, like “17w ago”. Under three weeks, the app says don’t apply, whatever the weather.
Recent activity sits on the dashboard, so the last few jobs are visible at a glance.
Money spent adds up the cost from every entry where you filled it in.
pH over time is drawn as a graph, so you can see whether lime is working.

So on the Labour Day weekend you can open the app and see whether the lawn is due, without trying to remember what happened before the long weekend in May.

What can a season of logs tell you?

After a year or two, patterns show up:

The lawn browned in the July you mowed at 5 cm and stayed green the next summer at 7.
The May overseeding barely came up, while the late August one filled in within a month.
The April fertilizer made no visible difference, and the one in late May did. Soil temperature, not the calendar, was the reason.

When the soil is warm enough and when to wait is covered in When to Fertilize Your Lawn in Canada.

What a Green Lawn has the lawn log built in and combines it with your local forecast to tell you when the next job is worth doing.