Iron Boost Liquid Fertilizer (2-pack)

Name: Iron Boost Liquid Fertilizer (2-pack)
Brand: Sunday
SKU: SBA3089
Price: 54.00 USD
Availability: InStock

$54 $60

(2) 42.3 fl. oz. pouches & hose end sprayer

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Premium liquid lawn fertilizer — iron

Supercharged iron citrate and high nitrogen blend for the deepest lawn greening and growth.

Free shipping! Ships in 1-2 business days

Wondering what your lawn really needs?

Let's create a custom plan for you.

We're committed to making sure Sunday works for you and your home. Need a replacement? Or help troubleshooting an issue? Our experts are here for you. Learn more

Green up your lawn fast

Grow the greenest lawn on the block fast with our highest iron concentration formula.

Supercharged with iron citrate, Iron Boost provides rapid deep greening, sustained growth and address iron deficiencies in your soil. Need more? The nutrient-rich combo of potassium and seaweed extract increase stress resilience for every blade. A new and improved formula for a greener, healthier lawn.

A Sunday premium selection

Premium fertilizers, enriched with potent nutrients and unique soil enhancers, outperform standard options to deliver superior, long-lasting lawn health.

Product features:

20-0-1 NPK (nitrogen-phosphorus-potassium) liquid lawn fertilizer
Premium fertilizer — concentrated nutrients and specialty ingredients
Addresses iron deficiencies in soil
Supports rapid deep greening, growth and stress resilience
Made for any lawn and grass type
Formulated without pesticides
User-friendly hose-on application
1 pouch covers up to 5,000 sq. ft.
Includes liquid fertilizer in flexible reduced plastic packaging and a custom-engineered universal hose-end sprayer

Ingredients:

Nitrogen: For healthy grass growth
Iron citrate: For rapid deep greening
Potassium and seaweed extract: For stress resilience

Instructions:

For best results, apply early morning or evening, and make sure your lawn is adequately hydrated. Avoid use on drought-affected or heat-stressed lawns.

Connect the universal sprayer to your hose and the fertilizer pouch. This sprayer is designed for the optimal mix of water and nutrients.
Apply the fertilizer across your lawn until the pouch is empty, which should take about 10-15 minutes. Once the fertilizer dries, you can get back out on your grass.
Reapply every 4-6 weeks spring through fall. Keep the sprayer for future applications

Helpful Tips from Lawn Advisors:

What does iron do for my lawn?

Iron helps give your lawn a deep green color, kickstarting its growth without adding too much nitrogen. It's not just for looks; iron also strengthens grass growth and root health.

Why is my soil deficient in iron?

Iron can be hard for grass to absorb from soil, which is why it might seem deficient. Sunday includes iron in a chelated form in many of our products, making it easier for your grass to take up and benefit from.

How are Sunday premium liquid fertilizers different?

Sunday's premium liquid fertilizers, once exclusive to custom lawn plans, are highly concentrated with nutrients, soil amendments, and specialty ingredients for effective and fast results.

How to apply boost pouches alongside other Sunday fertilizers

Boosts with nutrients can be used in combination with your Sunday Lawn Plans or other fertilizers. For best results, follow the instructions below.

For liquid fertilizer: First, apply the boost pouch, then wait 7 to 10 days before applying the liquid fertilizer.
For granular: Apply boost pouch, wait 4-6 weeks, then apply granular fertilizer.

When is it safe for people and pets to go on my lawn after applying?

Our ingredients break down quickly and don’t persist in the environment. After our products dry, you can get back to using your lawn!

Are there any US states where this is not approved for use?

This product is approved for use in all states.

Sunday liquid lawn fertilizer pouches side by side on a lawn

Liquid Lawn Fertilizer Instructions

Get a greener lawn with Sunday's nutrient-rich liquid lawn fertilizers. Follow our easy instructions and application tips for optimal growth and greening across your lawn.

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Customer reviews

0 Reviews, 7 Q&As

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REVIEWS
QUESTIONS

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Updating Results

07/13/25

Andrew

05/08/25

Q: How long after I use the Iron Boost can I put down new seed?

Store Owner

05/09/25

A: Great question! You can seed as soon as the fertilizer dries.

Stephanie

05/19/24

Q: After using Iron Boost, how long should I wait before watering my lawn again?

05/20/24

A: We recommend waiting 24 hours after application before watering!

Taylor

04/25/24

Q: Am I supposed to go through one full pouch each time I apply?
I used this pouch on my entire lawn, front and back, and only used a portion of the pouch.

04/26/24

A: Each pouch should cover 2,500 square feet when applied evenly. One pouch should take approximately 10-15 minutes to empty when using our hose-end sprayer. If you are having trouble with your application, our team would love to help you! You can reach them at [email protected] or by calling 415-903-6932.

Brad

04/22/24

Q: Is there a certain temperature the ground needs to be for this to be applied? It just rained but the temperature is dropping to mid to high 40’s and will be high 40’s in the morning. Will it be okay to apply this then? Thanks

04/23/24

A: Optimal temperatures are between 50F to 85F for the fertilizer to be most effective.

Brad

04/22/24

Q: Will this kill newly planted trees?

04/23/24

A: Our nutrients do not contain any herbicide so it will not actively kill anything; however, it is formulated specifically for turfgrass so we don't recommend applying directly to other plants for best results.

Ivan

04/05/24

Q: I reseeded my lawn with bermuda grass 2 weeks ago, is it safe to apply Iron Boost?

04/05/24

A: For best results, we recommend waiting until new grass has started to sprout before applying Sunday nutrients.

Kathi M.

03/27/24

Q: When using the Iron Boost when can pets go back on the lawn?

03/29/24

A: Great question! We designed Sunday with safety in mind, so we are extremely selective about not only the ingredients we use but also the lawn and garden techniques we recommend. Our ingredients break down quickly and don’t persist in the environment. After our products dry, you can get back to playing outside right away.