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New lawn #823785

Asked March 28, 2023, 9:54 PM EDT

We seeded our new lawn at our new home last September 1st. Mowed 2 or 3 times last fall. Should we just focus on fertilizing this year and forget crabgrass pre emergent, weed killer etc. until next year? Or are we better off trying to keep weeds/crabgrass to a minimum this year along with fertilizer? Thank you for your help!

Anoka County Minnesota

Expert Response

Thanks for the question.

You should have your soil tested to see what nutrients, if any, are deficient. Perhaps you have recently done this? If so and you have the soil report, please send it to us. Just applying fertilizer to your yard without knowing what is needed can be throwing away your money and/or risking over fertilizing. The University of Minnesota has an excellent soil testing laboratory that for a nominal fee can do this. See:

https://soiltest.cfans.umn.edu/testing-services

Additional comments:

1). Since you mowed three times last fall, it would appear that your seeding was successful. For this reason additional seeding this spring (2023) seems be unnecessary. Depending upon how things grow this season, additional fall seeding may be appropriate.

2). Applying a fertilizer with pre-emergent crabgrass control could certainly be done. In fact, should be done within the next few weeks. See:

https://extension.umn.edu/yard-and-garden-news/controlling-crabgrass-your-lawn

3). If you have your soil tested now and wait for the results before applying fertilizer with pre-emergent control, it may be too late for the pre-emergent herbicide to be effective. The timing here is critical. I would suggest that you apply the fertilizer with crabgrass control now. Then submit one or more soil samples for testing in mid to late May. Use the results of that testing to determine the degree of fertilizing that should done later in the season.

4). Applying some additional weed controlling measures (post-emergent), could be done once you start seeing weeds appearing. See the following for optimal times at which this could be done:

https://extension.umn.edu/lawn-care/lawn-weeds - postemergence-herbicides-1536711

Please get back to us if you have any additional questions. Good Luck.

An Ask Extension Expert Replied March 29, 2023, 9:22 AM EDT
Thanks for your response.
We actually did a soil test of our front yard and one for the backyard before we seeded. I have attached a photo of each.
Still too much snow to see how the new seedlings survived the winter. I also did some dormant seeding on a few areas that were pretty thin so will not be able to use pre-emergent crabgrass control on those spots.

Any guidance on how to proceed would be greatly appreciated.
image0.jpegimage1.jpeg
Sent from my iPhone

On Mar 29, 2023, at 8:22 AM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied March 29, 2023, 3:42 PM EDT

Thanks for your response and the reports.  Before examining them closely, I have a question.  One report lists "pond" and the other lists "road".  Can you verify for me that both reports were from a lawn area.  Perhaps "pond" referred to your lawn by a pond and the other to a lawn adjacent to a "road"?

Looking forward to your clarification.  Thank you a again.

An Ask Extension Expert Replied March 29, 2023, 5:30 PM EDT
Yes both reports are from our lawn. Just a couple names I used. 
Road is our front yard, pond is our backyard.
The samples were taken after our yard was graded but before a couple of inches of black dirt was spread over the entire yard.
I know it would have been ideal to do the testing after the black dirt was spread, but we had pretty tight time restraints last fall to get the seeding done before it was too late in the fall.

Sent from my iPhone

On Mar 29, 2023, at 4:30 PM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied March 29, 2023, 5:46 PM EDT

Thanks again for your response.

With respect to the two reports:

1). Both indicate a coarse soil texture. This simply means that there is a relatively high sand content in the soil. This is very typical in your county. This texture means that water drains rather quickly through the soil. Among other things, it suggests that for you to develop good turf, watering well will be a necessity. Blue grass may have some difficulty in growing, especially during hot summer months.  Expect some browning of your turf during the summer as the grass enters a dormant state.  Hopefully your seeding last fall contained a high percentage of fescue as this type of grass is much more drought resistant than bluegrass.

2). For both lawns you should consider only fertilizing in the spring and in the fall. Applying fertilizer in late June, July, and for much of August may lead to burning of your turf.

3). As soon as things melt (early April?), apply only a pre-emergent compound containing no fertilizer. This should help in preventing the germination of crab grass.

4).  In early to mid-May, apply a fertilizer that also can control seeds (e.g., “weed and feed”). Apply this same fertilizer and weed control in late August. This will prepare your turf for the upcoming winter. It is also the best time to control weeds.

5). One report (pond) indicates a proportion of 5-10-30 and the other report (road) suggests a proportion of 5-5-20. The middle number (10, 5) is for phosphate. Minnesota law prohibits the sale of lawn fertilizer containing phosphate so any fertilizer you use will probably show a middle number of 0.  No concern. The last number (30, 20) indicates the amount of potassium (AKA potash). Most fertilizers will have a potassium number lower than this. Don’t worry about this  either as the most important number is the first one (5), which is the nitrogen content. Basically look for a fertilizer having a first number of between 5 and 20 and let the third number fall where it may.

6). A popular brand of weed and feed has numbers of 28-0-3. This would suit your purposes nicely. Use this for your May and August fertilizations. Be sure to follow the application directions on the bag with respect to how much should be applied at any one time.

The following will give you some further information:

https://extension.umn.edu/planting-and-growing-guides/lawn-care-calendar

https://extension.umn.edu/lawn-care/fertilizing-lawns

Good Luck. Please get back to us with any additional questions.

An Ask Extension Expert Replied March 29, 2023, 6:44 PM EDT

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