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Heat Defense Granular 21-0-3 (12 lb)

One 12 lb bag covers up to 4,000 sq ft

LAWN PLAN EXCLUSIVE

Orange and green bag of Heat Defense Granular Fertilizer

Heat-season backup in one spread.

A 21-0-3 NPK granular fertilizer that improves water movement and moisture retention for steady greening and summer-season support, in one easy spread.

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LAWN PLAN EXCLUSIVE

Orange and green bag of Heat Defense Granular Fertilizer

Meet the granular built for hot, dry days

Exclusively available only in Sunday Lawn Plans

When temps rise and rain dips, this blend keeps your lawn on track. Premium ingredients support healthy growth and greener color, while the added surfactant helps water move into soil and reach roots more evenly, especially in arid regions. We also added leaf compost to support healthier soil. (Bet you didn’t know granular did that.)

One spread. One watering. Greener grass made simple. (We kept it humble. Your lawn won’t.)

The good stuff inside

  • Zero pesticide fertilizer —everything you need, nothing you don't
  • Universally loved by climates and grasses
  • Heat stress tolerance from potassium
  • Steady growth and green-up with nitrogen, calcium and sulfur
  • Builds organic matter from recycled leaf compost

How to use

Fill the spreader. Spread evenly for full coverage. Water in. Let dry. Go brag.

How soon will I see results with Heat Defense Granular?

With good moisture, you should notice a greener, thicker lawn in about 1 to 2 weeks.

Is Heat Defense Granular safe for all grasses?

Sure is. While designed with the arid West in mind, this product can be used on any lawn or grass type.

When should I apply Heat Defense Granular?

Late spring is prime time, right before summer heat. You can also use it ahead of a forecasted dry spell.

Will Heat Defense Granular let me water less?

No. It improves water movement and soil moisture behavior but does not reduce irrigation needs. To reduce watering needs, add Sunday’s Drought Defense into your normal routine. You can use it alongside any Sunday lawn fertilizer, liquid or dry.

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Sunday granular fertilizer products on lawn

Granular Lawn Fertilizer Instructions

Your lawn is a living thing. Soil, roots, microbes, the whole crew. Sunday's granular fertilizers feed that system slowly, so your grass grows steadily (instead of spiking and stalling). Here's how to put them to work

Read article

Customer reviews

Based on 10601 reviews!
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David
Verified Reviewer
LocationSparks, Nevada
I was skeptical, however seems

I was skeptical, however seems to be working. See before and after below.

Published date
10/10/25
Was this review helpful?
3
1
Becky
Verified Reviewer
LocationSpokane, WA
Finally!!!

It is an immense relief to find a yard care option that works with nature not against it. No more green short term facade, with poisoning long term destruction. And it's actually fairly affordable?!?!?! Wow. Mindblown. Thank you very much.

Published date
10/09/25
Was this review helpful?
1
0
Greg
Verified Reviewer
So far so good can’t

So far so good can’t wait for next season to see how everything is holding up? Time will tell.

Published date
10/09/25
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1
0
Matt
Verified Reviewer
LocationBlauvelt, New York
Plan is great. Customer support us even better

I started with a weed infested lawn. I had tons of questions and the guys were more than helpful with their responses. Will even went as far as making video responses to a video I sent showing my lawn's status. Super happy with the service.

Published date
10/09/25
Was this review helpful?
3
1
Ronald
Verified Reviewer
LocationMartinsville Indiana
Finally Making Some Progress with my Yard!!

This is my first year using the Sunday System. I have unsuccessfully tried the DIY yard treatment granules from the big box stores and tried hiring a truly green service to apply for me, but no success with either. From the pictures, you can see that for the first time in ten years, I am finally mak...

Published date
10/08/25
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0
0
Jeff
Verified Reviewer
LocationFallon, Nevada
Sunday is dialed in to your needs 100%

My lawn was close to impossible to improve, let alone maintain. Huge patchy areas, tons of weeds, always dry looking despite the constant watering; nothing was helpful from the store bought products. I decided to try Sunday, in June. Sent my soil sample in started using the plan sent fertilizers im...

Published date
10/08/25
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0
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Melissa
Verified Reviewer
LocationSpokane, WA
Sunday lawn service is great !!

I started using Sunday at the beginning of the summer and my yard is a lawn now. It's beautiful. And very very thick!!

Published date
10/08/25
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0
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Erin
Verified Reviewer
LocationMonroe, WA
Such an easy to follow system!

I love that the products just show up, I don't have to mark dates on my calendar or research what I'm supposed to be doing now. Getting the emails telling me which product to use now; and having Sunny to ask questions has been a game changer. I have been following the plan for about 6 months now and...

Published date
10/08/25
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0
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Sean
Verified Reviewer
LocationPittston, PA
First Season

We live in a wooded area where I am always fighting to get the grass to grow between the board of the yard and the forest. The fertilizer I received in my first box I feel made a difference with the existing grass we already had. With our new puppy I did utilize the urine resistance seed to get the ...

Published date
10/08/25
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1
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Donna
Verified Reviewer
LocationGrayson county Texas
Healthiest on the Block

I do love using Sunday products on my too large lawn! I found them to be economical too compared to the dry fertilizers that never spread as far as they promise

Published date
10/08/25
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