When to Fertilize New Kentucky Bluegrass Sod

Published Categorized as Sod & Seed

Like any other plant, Kentucky Bluegrass sod, requires good care to flourish. In addition to sunlight and moisture, soil nutrients are essential for this turf to grow healthy. However, some soil types, such as sand or gravel, need more nutrients to boost the development of this Bluegrass. That’s why fertilizing is vital to supplement the nutrients necessary to maintain a healthy lawn. But the question is, when to fertilize Kentucky Bluegrass sod?

You should first fertilize new Kentucky Bluegrass when planting but use an organic or starter fertilizer that won’t damage sod. Fertilize again with a more traditional or organic fertilizer like 18 -1-8 formulation after 4-8 weeks. This period should be around March or April when the sod roots are fully established. Apply once more a slow-release fertilizer once or twice in October or November.

Related: Why is My New Sod Dying After 3 Months?

When to Spread Fertilizer on Kentucky Bluegrass

Fertilize New Kentucky Bluegrass Sod

Maintaining a healthy Kentucky Bluegrass lawn using fertilizer is vital. However, timing is key. So, here is the schedule for fertilizing your sod;

1. When planting

Kentucky Bluegrass’s new sod requires varied amounts of phosphorous, nitrogen, and potassium to grow. Therefore, to ensure the soil has enough nutrients, apply fertilizer before laying the sod. Use an organic or starter slow-release fertilizer instead of weed & Feed, as it might harm your sod’s tender roots.

2. During winter

To stimulate a deep root system, fertilize your Kentucky Bluegrass sod in late winter (late February/Early March). However, you must test the soil temperature and ensure it’s 50 degrees. Apply a low-phosphorus, high-nitrogen fertilizer like 18-0-4.

3. Spring

Apply 12-4-8 fertilizer in mid-spring, which is usually from 1st April. This should be around 4-8 weeks after the late winter application.

4. Summer (if necessary)

It’s not a good idea to fertilize Kentucky Bluegrass sod in summer. However, sometimes it may be required, especially if your lawn turns yellow or light green. In this case, you should fertilize lightly and water your sod correctly.

5. Early fall

Fertilize your sod again in early September using a fertilizer with a slow release of nitrogen and high potassium but low phosphorous. For instance, you can use 12-0-12 or 12-4-14.

6. Winter

When fertilizing during winter, it’s vital to remember that the sod doesn’t absorb nutrients during low temperatures. So, fertilizer is unnecessary when the soil temperature is below 45 degrees Fareinheit.

Also read: Can You Lay Sod Over Snow?

Frequently Asked Questions (FAQs)

Q: How much fertilizer does Kentucky Bluegrass need?

A: Kentucky Bluegrass requires an average of 3 to 6 lbs. of actual nitrogen fertilizer per 1000 sq. ft. of yard yearly.

Q: What happens if you fertilize Kentucky Bluegrass too soon?

A: Fertilizing your sod soon is a waste of resources and time. Note; you already fertilized when planting, so the grass is not ready to absorb more fertilizer. Therefore, the soil will contain excess fertilizer that may burn your grass, giving it an off-color. This exercise may also cause a nutrient deficiency in the ground, turning your lawn yellow.

Q: What type of fertilizer to use on my Kentucky Bluegrass?

A: The best fertilizer for Kentucky Bluegrass sod is a slow-release one like N-P-K 12-4-8. This means the Nitrogen (N), Phosphorous (P), and Potassium formula ratio is 3-1-2.

Must read: How to Lay Sod in 7 Easy Steps


It’s crucial to fertilize your lawn at least 3-4 times between spring and fall. The first time to apply starter slow-release fertilizer is when installing the sod. After that, fertilize again after 4-8 weeks to stimulate a deep root system. Apply again once in early fall and once during winter.

To ensure the fertilizer work effectively, water your Kentucky Bluegrass properly and consistently.

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By Wycliffe Magara

Hi, my name’s Wycliffe Magara, a professional landscaper, journalist, published author, photographer, and lawn attendant. Apart from this site, I also own LawnAffection, Grasstology, and TheScholarshipTipster. I specialize in creating informational content to help you grow a Lifelong Lush Lawn and find the ideal scholarship opportunities no one ever talks about.