# What to add based on soil test



## Ylli (Sep 24, 2018)

Did a soil test in my problem area (shade, bare spots), and came up short on P & K. The lawn service is going to do a mechanical aeration in a couple of weeks and I am going to overseed, so I don't want growth of the existing grass crowding out the seedlings. But I do want the soil in reasonable condition to germinate and establish the new grass. Have recently applied Custom Liquid Solutions 'Soil Loosener' and 'Root Hume'.

Will be overseeding with mostly TTTF (United Seed Super Turf I LS), with a bit of KBG (United Seed Bewitched) and some FF (United Seed Super Shade Fine Fescue Blend) thrown in.

Looks like I need about 1 lb/M of both P and K. Is there anything out there like 0-25-25? Am I looking at this right?


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## Virginiagal (Apr 24, 2017)

There are phosphorus only and potassium only fertilizers. You'd find them at a farm supply store, not in your local garden center. TSP is 0-46-0 and SOP is 0-0-50. It would be good to get the phosphorus down when aerating as it's not very mobile and that would help get it into the root zone. If you can't find these fertilizers, you can use a balanced fertilizer like 10-10-10. If you don't want the existing grass to get the nitrogen from a balanced fertilizer then you could delay it until the new grass comes up.


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## ladycage (Aug 12, 2019)

My soil is lacking in P,K also and I found a 0-52-34 product at kelp4less.com it is MKP, I am going to try to see if that helps increase my levels without adding N.


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## Virginiagal (Apr 24, 2017)

@ladycage I just looked at that product:
https://www.kelp4less.com/shop/soluble-mkp/
It is a powder, not a granular fertilizer. It's not really designed for lawns, it's described as a bloom enhancer. You will have to mix it with water and spray it. It is also very expensive. Forty pounds of 10-10-10 at Walmart is $9.00.


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## Virginiagal (Apr 24, 2017)

@ladycage Use the directions on the package for how much to use over such and such sq ft. This is a foliar feeding, not a soil feeding, so will not jive with the recommendations on your soil test. It was a soil test; they are recommending products applied to the soil. Two ways to look at this: 1) Your grass won't be depending on your poor soil for these nutrients. Or 2) your poor soil will remain poor soil.


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## ktgrok (May 25, 2019)

It's okay to add nitrogen too - they generally don't give reccomendations for that nutrient. Agree with others that if you are low in both use a 10-10-10 or 20-20-20.


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## ladycage (Aug 12, 2019)

Virginiagal said:


> @ladycage Use the directions on the package for how much to use over such and such sq ft. This is a foliar feeding, not a soil feeding, so will not jive with the recommendations on your soil test. It was a soil test; they are recommending products applied to the soil. Two ways to look at this: 1) Your grass won't be depending on your poor soil for these nutrients. Or 2) your poor soil will remain poor soil.


Thanks for the help and recommendation. I called the company and found out that the MPK is used on lawns and applied with a hose end sprayer and applied to the soil not foliar, the rep said the problem would be applying it to 16k would take a while refilling the hose end sprayer so he only uses the the MPK for the front 1200 sq ft of his front yard and uses granular fertilizer for his back yard which is 10k he said. So you are right it is much cheaper to use the 10-10-10 or 13-13-13 granular 40# for $14 at Lowes. I will just apply the 13-13-13 @ 7# twice yr as recommended . and 34-0-0 twice a yr with humic/fulvic @ 3oz/M 4x yr, does that seem good?


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## Virginiagal (Apr 24, 2017)

@ladycage Yes, the fertilizer plan sounds fine. Since you have a low cation exchange capacity (as Ridgerunner calculated), you might consider splitting the amounts in half and doing twice as many applications. So, for example, instead of every six weeks, which is about what Georgia recommended, you could do a half application every three weeks. That's more for the nitrogen than the complete fertilizer applications, to minimize leaching. If you want to use the Carbon X for the summertime nitrogen applications, go right ahead. It's mostly nitrogen and the bit of extra potassium won't hurt a thing. As for the humic, just do whatever the package recommends. I expect there is variation from each producer. Glad you talked to the company. Granular applications will be easier. Make sure to water each application in.

@Ylli Sorry for interrupting your thread. Hope all is going well with your overseeding.


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## Ylli (Sep 24, 2018)

No problem. The lawn service did a pretty thorough job of core aerating, and I spread about 30 lbs of seed over 5kft². Worked it into the soil with the lawn tractor dragging a spike aerator. Hopefully that made for good seed/soil contact. Watered for a week, and now we are having about a week of daily rains, so I got my fingers crossed. Don't see anything yet. Figure I'll spread some Scott's starter fertilizer in another week or two to try and bring up that P & K.


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## Virginiagal (Apr 24, 2017)

Hope the seed is not too deep. TTTF should be mostly up after two weeks. If after next week you still don't see much, it would be good to add more seed. Maybe it's just making it way up and hasn't broken through. Have you had to cut the existing grass? I overseeded TTTF Friday and saw grass babies yesterday, more today. It's been hot here and I have been keeping everything well watered. My existing grass hasn't grown much and I'm hoping to not have to cut for another week.


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## ladycage (Aug 12, 2019)

Good luck with the seeding, I wish we would get some rain. You should see some germination next week unless the seeds are too deep. Keep us posted.


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