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Cass County Extension

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Lawn Care

Aeration Fertilizing Mowing
Raking/Power Raking Seeding/Soding Watering

Aeration

Is aeration a good idea?

Yes, especially if your lawn has never been aerated. Sodded lawn should be aerated yearly for the first 6-8 years. Aeration takes plugs of soil out of the ground and opens up the soil for better air, water and fertilizer penetration.

Is the fall a good time to aerate the lawn?

Fall aeration is commonly done in other parts of the country. Aerating in the fall or spring would be fine, but we need about six weeks of good growing conditions after aeration. 

Fertilizing

How early should fertilizer be applied in the spring?

Try to wait until the soil warms up and the grass is actively growing. According to our bulletins, lawns should be fertilized in mid-late May, after the first flush of growth, but most of us have a hard time waiting that long.

When should the lawn be fertilized?

Usually we recommend one application of fertilizer in the spring around Memorial Day and another in the fall about Labor Day. If your lawn is in poor condition you may want to make two applications in the fall.

Should lawns be fertilizing in mid summer?

It is recommended that we not fertilize in July or early August unless we have and use a sprinkler system regularly.

When should we apply fertilizer in the fall?

The first half of September is fine. If the lawn is in good shape, applying a winterizing fertilizer is recommended.  If a lawn need extra help, applying a fertilizer in late October could also be done.

Is late fall fertilizing a good idea?

I don't know if it's a good idea but fertilizer can be applied late in the fall and will be available for the grass when it emerges in the spring.

What should we look for when purchasing a lawn fertilizer?

We want a fertilizer that is made for lawn usage. This would be at least partly a slow release fertilizer. A lawn fertilizer should have at least 20% nitrogen. That means that the first number of the sequence on the fertilizer bag should be a 20. The other 2 numbers indicate the percentage of phosphorous and potassium. Much less of these are needed by the lawn in the spring of the year.

What procedure should be used in applying fertilizer?

Don't try to scatter fertilizer by hand. Usually you won't be very satisfied with the results. Use a spreader and set it according to directions on the fertilizer bag. Don't increase the amount of fertilizer applied. Applying too much fertilizer will burn the grass. Water the fertilizer into the ground shortly after applying if we don't receive rain.

Will fertilizer help to thicken up an existing lawn?

Yes, fertilizer will cause the grass plants to grow vigorously and increase in size. But if a lawn is real thin, seeding will still be necessary to increase the number of grass plants.

What type of fertilizer is best for the lawn in the fall?

When selecting a lawn fertilizer we can either select a lawn fertilizer high in nitrogen which will stimulate grass growth or if our lawn is in fairly good shape we may want to use a winterizing fertilizer in which the amount of nitrogen, phosphoros and potassium are more balanced. The 3 numbers on the fertilizer bag or box will tell you the percentage of nitrogen, phosphorous and potassium. 

Mowing

What is the ideal height for cutting lawn grass?

Most lawns in our area are a mixture of Blue Grass and Creeping Red Fescue. These grass will do their best when cut at between 2" and 3" high. At this height, the plants shade the soil and helps keep weed seeds from germinating. Cut the grass when it reaches 3" to 4" in height.

Do you feel that it's necessary to bag lawn clippings or is it alright to just leave them on the lawn?

From the latest research I've seen leaving the clippings on the lawn is the way to go. The clippings are high in moisture and nitrogen and break down quickly.

Are there times when the clippings should be bagged?

Yes, if the lawn gets away from you between cuttings and you need to take off more than an inch of grass when cutting or if the dandelions are all seeded out.

At what length should the grass be cut the last time we mow in the fall?

We recommend cutting at the same length as it has been mowed all through the year. If we cut it real short and have an open winter we have more chances of winter damage. If we leave it long and we have a slow melt in the spring, snow mold will be a greater problem.

Raking/Power Raking

How early in the spring can the lawn be raked?

Once the snow is gone and the lawn surface is starting to dry, we can safely rake the lawn lightly with a leaf rake. Power raking should not be attempted until the lawn is dry.

How do we know if the lawn needs to be power raked?

If the thatch layer is more than 1/2" deep power raking is beneficial for the lawn. Most individuals power rake for cosmetic reasons rather than because the lawn needs it.

Seeding/Sodding

When it a good time to interseed or seed a lawn?

Grass seed can be planted in spring, around Labor Day in the fall (before September 15) or just before winter sets in. The seed needs to be worked into the soil just slightly with a garden rake.

Can a lawn be seeded and fertilized at the same time?

Yes, but only if the level of fertilizer application is very low. If a normal application of fertilizer is applied it will tend to damage the germinating grass seeds. It's usually best to fertilize, water well and then seed at a later date.

How late into the fall can we seed or sod a lawn?

We don't recommend planting grass seed later than September 15  or sodding after October 1.

Is October too late to plant grass?

Yes, this is not a good time to plant grass. It would come up this fall but not be established well enough to overwinter. If you want to seed this fall, wait until just before the first snow. The seed will lay in the soil and come up next spring. 

Watering

Is it necessary to water the lawn?

The grasses grown in our area are cool season grasses which green up early in the spring and stay green until late fall. During the hot summer months they may go dormant until the temperatures cool and the amount of moisture increases. If we want a nice green lawn during the summer months we must water if it doesn't rain.

How much water a week does a lawn use?

The average lawn uses about 1 - 1 1/2 inch of moisture a week. This should be provided by rainfall or 1 to 2 deep watering a week. It takes about 2 hours to apply 1" of water with average size hose and water pressure.

How much drought can lawn grass take?

Guess I can't give an absolute answer to that question. I'm sure that without water the grass would eventually die, but so would all the other plants. It is normal for our lawns to go dormant during hot dry periods of weather.

What can be done to help the lawn grass survive droughty conditions?

There are several things which can be done. Set your mower up so that you cut the grass higher than normal. The taller grass will shade the grass roots and reduce the heat at soil level. Don't fertilize unless you can and do water. Mow your grass less often. Wounds caused by mowing are a source of lost moisture. If you don't have a layer of thatch allow the grass clipping to fall and provide a mulch which will reduce the water loss from the soil.


Todd Weinmann, Extension Horticulturist & Master Gardener Coordinator
Phone: (701) 241-5707
E-mail: todd.weinmann@ndsu.edu

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