Green-Up Your Lawn In Spring

The exact timing of lawn care tasks depends upon the weather. If you're still getting snow in your area, start when you are confident the snow season is over.

When spring is in the air, you'll see the first crocuses or daffodils return, marking the coming of the season. These signs should also signal to you that it is time to get your lawn ready for the growing season. You'll want to start when you are pretty confident the snow season is over.

Another good indicator is about the time the local forsythia plants stop blooming, and the local lilac bushes begin to flower. For most people, there are eight tasks you should do or think about as you head into spring.

Here are 6 tasks to help get your lawn ready for spring!

Image showing soil layers including thatch.

Raking is the first thing you need to do when getting your lawn ready for new growth. You probably think, "But, my trees had no leaves falling for months. Why?" Even if you did a phenomenal job of raking leaves in the fall, you still have to contend with thatch.

Thatch Basics

Thatch is the layer of mainly dead turf grass tissue lying between the green vegetation of the grass above and the root system and soil below. This layer, if it becomes too thick (½-inch or more), can be bad for the health of your grass. Thatch is why you should rake deeply when raking leaves in the fall.

You still need to rake in the spring, no matter how good a job you did in the fall. You need to remove the grass blades that died over the winter. You do not want that dead grass turning into thatch.

Spring raking is when you can find matted patches of lawn. If you inspect carefully and notice the grass blades are all stuck together, a lawn disease called snow mold may be to blame. New grass may have difficulty penetrating these matted patches, and raking can solve this problem.

When To Start Raking

It’s best to give the lawn time to warm up, dry out and start waking up from dormancy before raking it. So wait until all the snow has melted, the ground has thawed, and your lawn begins to turn green before you start to rake grass in spring.

Spring is NOT the ideal time to aerate the lawn.

Performing lawn aeration If your lawn gets heavy traffic, such as lots of running and playing in the same spot, this can cause soil compaction.

If you see moss, which thrives on compacted soil, you can get rid of it, but you need to look deeper into its root cause. In this case, it is your soil. It needs aeration. A lawn aerator creates openings in lawn turf that allows water and air to penetrate the soil and reach the grassroots.

However, circumstances may require it. If soil is compacted to the point that existing grass can't grow, it may be necessary to aerate in the spring.

Generally, though, spring aerating is discouraged because the aeration holes provide a perfect spot for weed seeds to germinate. Weeds (especially crabgrass) are the first seeds to germinate in the spring, and aerating the lawn stirs them up and gives them an ideal home.

If you must aerate in the spring, consider around Memorial Day after weeds have started growing but before they go to seed.

The first step in going the organic route with an existing lawn is beefing up weakened soil, which means starting with a soil test. That way you'll know which nutrients are lacking and which organic amendments you'll need to incorporate.

For example, soil with a calcium deficiency can be top-dressed with gypsum; and soil low in magnesium might need a healthy dose of the mineral langbeinite. You will need to dig up samples from several different areas of your lawn (2 cups of soil total), and mail them off to a lab to be analyzed.

In Wisconsin, you can contact the US Soil and Forage Lab to request a soil test. Their web site contains instructions on how to collect and submit soil samples.

Once you know which amendments you need, you should prepare the lawn by mowing the grass down to about 2 inches, pulling up weeds and removing thatch (as discussed earlier). This will enable your soil to fully absorb any amendments you add.

Spreading lawn grass seed A lawn riddled with bare patches due to dog spots, heavy traffic, or neglect may need an application of grass seed to fill in those bare patches.

Over-seeding is the process of sowing seed over existing grass. Apply a slow-release nitrogen fertilizer when you over-seed. Five weeks after the grass germinates, apply quick-release nitrogen fertilizer.

Fall is the preferred time to do your over-seeding, but if your grass is in dire need of help, do it. You just might have to contend with some crabgrass cropping up and feeding off of the fertilizer.

In spring, crabgrass starts germinating when soil temperatures warm to 55° F for 4-5 days in a row. Do not plant new grass seed if you applied pre-emergent crabgrass killer as it will kill germinating grass seed.

Resist your urge to schedule early spring fertilization. Wait until mid to late May to apply your first spring lawn fertilizer.

Leftover nitrogen nutrient from last year’s fall fertilization and the nutrients released from the decomposition of organic matter in the soil should be plenty enough for the grass to grow in spring. In fact, early spring fertilization can induce excess blade growth at the expense of the root growth.

Experts recommend a lighter feeding in spring and a heavier one in late fall for cool-season grasses.

Fertilize your lawn when it’s consistently in the 60s during the day — soil will be in the 50s — probably about mid to late May.

Too much fertilizer in spring can lead to disease and weed problems. And if you fertilized in late fall, then your lawn still has fertilizer to feed on in spring.

Green-Up Your Lawn In Spring

The exact timing of lawn care tasks depends upon the weather. If you're still getting snow in your area, start when you are confident the snow season is over.

Spring is NOT the ideal time to aerate the lawn.

Resist your urge to schedule early spring fertilization. Wait until mid to late May to apply your first spring lawn fertilizer.

Read more: Fertilizer Basics, a Wisconsin Pollinators reference guide.