What should I do to my lawn in March in Illinois?

Cleanup and preparation only. Pick up debris, service the mower, cut back perennials and prune summer blooming shrubs. Stay off saturated turf and do not fertilize or mow, since the grass is still dormant and the soil compacts easily.

What is the most time sensitive spring lawn task?

Crabgrass pre emergent, which must be applied before soil temperatures reach about 55 degrees, usually mid to late April on the North Shore. It is the one spring task where missing the window by two weeks costs you the whole season.

When is the last frost in Lake County, Illinois?

Mid May is the usual guideline for Lake County, though late frosts happen. Wait until roughly May 15 before planting tender annuals and vegetables, and keep covers handy for a week or two after.

Should I aerate my lawn in the spring?

Fall is better. Late August through early October gives warm soil, active grass growth and almost no weed competition. Spring aeration works but opens the soil right as crabgrass and summer weeds are germinating.

Seasonal · Lake County

A Month by Month Spring Lawn Care Checklist for Illinois

What to do in your Lake County yard in March, April and May, in the right order, so nothing important gets missed or done too early.

By Mario Ruiz · Ruiz Landscaping

March 5, 2026 · 6 min read

Spring lawn care is less about effort than sequence. Most of what goes wrong in a Lake County yard comes from doing the right task at the wrong time. Here is the order we work in, month by month.

March: clean up and get ready

The ground is still thawing and often saturated. Almost everything you might want to do to the turf itself should wait, but there is plenty to prepare.

Pick up branches, trash and leftover leaf piles as areas dry out.
Get the mower serviced and sharpen the blade before the shops get busy.
Cut back ornamental grasses and perennials you left standing for winter interest.
Prune summer blooming shrubs, but leave spring bloomers like lilac and forsythia until after they flower.
Stay off soggy lawn areas entirely. Every footprint on saturated clay is compaction you fix later.

April: the important timing month

April is when the decisions actually matter, because two time sensitive windows land in it.

Light cleanup raking

Once the surface has dried, rake matted areas open and clear any snow mold patches. Look over the salt damaged strips along the driveway and plan repairs.

Crabgrass pre emergent

This has to go down before soil temperatures reach about 55 degrees, generally mid to late April here. Miss it and you are fighting crabgrass all summer. Remember you cannot seed an area you have treated.

First mow

When the grass is actively growing and hits about three inches, take the first cut. Set the deck high. There is no benefit to a short first mow.

Spot seeding

Repair bare patches now, keeping them away from any pre emergent you applied. Cool damp April weather is genuinely good for germination.

May: the lawn hits its stride

By May the lawn is growing hard and the yard needs consistency more than intervention.

Mow every five to seven days, never removing more than a third of the blade.
Apply the first fertilizer of the year once the lawn has greened up and been mowed a few times, around mid May.
Spot treat broadleaf weeds, though remember fall treatments are far more effective on perennials.
Edge beds and refresh mulch to two or three inches, keeping it pulled back from trunks.
Plant annuals after the frost risk passes, which is generally around mid May in Lake County.
Check the irrigation system, and start the one inch per week routine only once rain tapers off.

What to leave for fall

Two big jobs tempt people in spring and genuinely belong in autumn. Core aeration and major overseeding both work better in late August through September, when soil is warm, weed competition has collapsed, and the lawn has weeks of ideal growing weather ahead. Doing them in spring is not wrong, it is just less effective.

If you would rather have all of this simply happen on schedule without tracking soil temperatures, that is what our maintenance customers pay for. Call or text 224-634-0673 or 224-200-8363.

Frequently asked questions

What should I do to my lawn in March in Illinois?: Cleanup and preparation only. Pick up debris, service the mower, cut back perennials and prune summer blooming shrubs. Stay off saturated turf and do not fertilize or mow, since the grass is still dormant and the soil compacts easily.
What is the most time sensitive spring lawn task?: Crabgrass pre emergent, which must be applied before soil temperatures reach about 55 degrees, usually mid to late April on the North Shore. It is the one spring task where missing the window by two weeks costs you the whole season.
When is the last frost in Lake County, Illinois?: Mid May is the usual guideline for Lake County, though late frosts happen. Wait until roughly May 15 before planting tender annuals and vegetables, and keep covers handy for a week or two after.
Should I aerate my lawn in the spring?: Fall is better. Late August through early October gives warm soil, active grass growth and almost no weed competition. Spring aeration works but opens the soil right as crabgrass and summer weeds are germinating.

Want a hand with your yard?

Ruiz Landscaping is Mario Ruiz's family-owned crew serving Vernon Hills and the North Shore. Free estimates, fair prices, fast replies.

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Ruiz Landscaping serves Vernon Hills, Libertyville, Mundelein, Buffalo Grove, Lincolnshire, Long Grove and the rest of Vernon Hills's surrounding North Shore and Lake County communities.