Fish Heads in the Garden? This Ancient Trick Could Be the Secret to Your Best Tomato Crop Yet

If you’re prepping your garden for tomato season, there’s a surprising, old-school trick that might just take your harvest to the next level: burying a fish head beneath your tomato plant.

Yep, you read that right. This might sound odd, but using fish heads in the garden is a time-tested technique that can deliver impressive results—and it’s backed by science and tradition.

Let’s break down how this natural fertilizer works, why it’s making a comeback, and how you can use it safely and effectively in your own backyard.

Why Bury a Fish Head Under a Tomato Plant?

Research shows fish heads are loaded with nutrients that plants crave—especially tomatoes. According to a study from Indonesia’s Environmental Science Master’s Program, fish heads contain:

• 8.3% nitrogen (for lush green growth)

• 4.8% phosphorus (promotes root and flower development)

• 1.6% potassium (improves fruit quality)

But there’s more going on beneath the surface. As the fish decomposes, it becomes a feast for soil microbes, earthworms, and fungi. These beneficial organisms break it down and release nutrients right where your tomato roots need them most.

The History Behind Fish Fertilizer

This isn’t a new idea. Indigenous farmers used to bury a small fish under corn seeds—part of the famous “Three Sisters” planting method with corn, beans, and squash. While modern gardeners often leave out the fish, it was actually the powerhouse ingredient that supercharged plant growth.

Reintroducing fish scraps into your gardening routine is a way to honor this time-honored tradition while boosting your soil naturally.

The Perks of Fish-Based Fertilizer

Unlike synthetic fertilizers, which release nutrients quickly (and sometimes harmfully), fish scraps act as a slow-release fertilizer that improves overall soil health.

Here’s what makes fish fertilizer so effective:

• Long-lasting soil improvement: Fish feeds the entire soil ecosystem, not just the plant.

• Gentle on plants: Fish-based nitrogen doesn’t “burn” plants like some synthetic fertilizers can.

• Trace minerals included: Calcium, magnesium, and other key nutrients help build stronger plants.

• Safe for young plants: Fish fertilizer is ideal even for seedlings and dry soil conditions.

• Reduces waste: You’re repurposing leftovers that would otherwise be discarded.

How to Use Fish Heads for Tomato Planting

You don’t need a boatload of fish to get started. Save fish heads and tails in a freezer bag throughout the year or ask your local fish market if they have any to spare.

Here’s a step-by-step guide:

1. Dig deep: Create a planting hole at least 18–24 inches deep.

2. Place the fish head: Drop the frozen fish head into the hole.

3. Cover with soil: Fill the hole with soil up to the point where your tomato will be planted.

4. Plant your tomato: Bury the tomato plant so that one-third of the stem is below the surface. Tomatoes grow roots along the buried stem, helping them anchor and thrive.

5. Water thoroughly and apply mulch to retain moisture and deter weeds.

Pro tip: Don’t use banana peels or eggshells here—they break down too slowly. Compost those instead.

What if You Don’t Have Access to Raw Fish?

No worries! You can still give your garden the fishy boost it needs:

• Canned sardines in water (not oil or flavored) can work in a pinch.

• Commercial fish fertilizers, like fish emulsion or fish meal, are cleaner and odor-free alternatives. These products are processed to kill harmful pathogens but still provide that nutrient-rich punch.

Popular options include:

• Fish Emulsion – a liquid fertilizer made from fish offal

• Fish Hydrolysate – a fermented fish-based fertilizer

• Fish Meal – a dried and ground mix of fish parts

DIY Fish Emulsion (If You Don’t Mind the Smell)

Want to go full-on homesteader? Here’s how to make your own fish emulsion:

You’ll need:

• Fish scraps

• Sawdust

• Unsulfured molasses

• A 5-gallon bucket with a lid

• Water

Instructions:

1. Fill the bucket halfway with equal parts fish scraps and sawdust.

2. Add 1 cup of molasses.

3. Fill the bucket with water to cover everything.

4. Stir daily for two weeks.

5. Strain the liquid—this is your fertilizer!

Dilute 1 tablespoon in 1 gallon of water and use it to feed your plants twice a week.

Know the Risks Before You Bury Fish in Your Garden

As effective as this method is, there are a few things to watch out for:

• Pathogens: Raw fish can carry bacteria like salmonella or parasites.

• Pests: The smell can attract raccoons, stray pets, or even rats.

• Heavy metals: Some fish may contain mercury or other toxins that could end up in your soil.

• Odor: Let’s be real—it can smell pretty bad if not buried deep enough.

Always bury fish at least 18 inches down and never use spoiled fish. If you’re unsure, go with processed fish fertilizer to avoid these risks.

Final Thoughts

Burying fish heads in the garden might not be the most glamorous technique, but it’s a natural, time-tested way to supercharge your tomato plants. Whether you go the DIY route or use commercial fish fertilizers, you’re investing in richer soil and a healthier garden.

So next time you’re prepping those tomato seedlings, think beyond the compost pile—think fish.

Your tomatoes will thank you.