Heat Defense Liquid Lawn Fertilizer (42.3 fl oz)

Name: Heat Defense Liquid Lawn Fertilizer (42.3 fl oz)
Brand: Sunday
SKU: SBA3332
Price: 25.00 USD
Availability: InStock
Rating: 4.3 (10586 reviews)

One pouch covers up to 3,000 sq ft

10586 reviews

LAWN PLAN EXCLUSIVE

Fertilizer for lawns in arid or dry conditions.

12-0-4 liquid fertilizer with slow-release nitrogen, seaweed, and surfactant. Builds heat resilience and improves water retention in drought-prone regions.

Shop custom plans

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

Low nitrogen. High resilience.

Heat Defense takes a different approach. Instead of pushing growth during hot weather, it helps your lawn survive it. The 12-0-4 formula keeps nitrogen low to avoid forcing growth. Seaweed strengthens roots. Surfactant helps water penetrate instead of running off.

Apply before heat arrives. Your lawn will handle summer better.

The good stuff inside

Low nitrogen 12-0-4 NPK Maintains color without forcing growth in heat
Surfactant Helps water soak into soil instead of running off
Seaweed extract Strengthens roots and improves heat tolerance
Potassium Water management when temps climb
Zero pesticide fertilizer—everything you need, nothing you don't
Universally loved by climates and grasses

How to use

Apply in late spring or early summer before heat stress begins. Less effective as rescue treatment during active drought.

1. Apply early morning or evening to a well-hydrated lawn.

2. Connect sprayer to hose and pouch.

3. Spray evenly until pouch is empty (about 10-15 minutes).

4. Water thoroughly after application.

5. Reapply every 4 weeks through summer.

FAQ

Can I apply Heat Defense during a heat wave?

It's less effective once grass is already stressed. Heat Defense works best as prevention. If temps have been above 90°F for several days and your lawn is showing stress, water deeply and wait for a cooler stretch before applying.

How is Heat Defense different from Drought Defense?

Heat Defense is a fertilizer (12-0-4) with surfactant included. It feeds your lawn while improving water penetration. Drought Defense (0-0-1) is just a wetting agent with minimal nutrients. Use Heat Defense for regular summer feeding. Use Drought Defense as a targeted treatment when you need maximum water efficiency without adding nitrogen.

Should I apply Heat Defense or weed treatment first?

Heat Defense first if summer stress is your main concern. Wait at least 1-3 days between applications. If weeds are actively spreading, treat weeds first, then apply Heat Defense at least 24 hours later. The surfactant in Heat Defense can affect how weed control absorbs, so you don’t want to apply them too close together.

I sprayed Heat Defense and a few days later some patches turned reddish. What does that mean?

That's likely rust fungus, not a reaction to Heat Defense. Rust appears as orange-red powder on grass blades, especially in humid conditions. Heat Defense doesn't cause discoloration. Mow regularly to remove infected blade tips and the lawn should recover as conditions improve.

Documents

Heat Defense SDS

Heat Defense Label