Fertilizer costs are getting out of hand.
A quality organic fertilizer can easily run $15-25 per bag, and if you’re growing anything substantial, you’ll blow through multiple bags per season. That’s money straight out of your grocery budget.
But what if I told you there’s a plant that acts like nature’s own fertilizer factory? One that costs nothing to make after your initial investment and actually outperforms many commercial fertilizers?
Meet comfrey—the homesteader’s secret weapon that most gardeners walk right past.
This humble plant might look like just another leafy green taking up space, but it’s actually a nutrient powerhouse that can slash your fertilizer budget while giving your plants exactly what they need to thrive.
Ready to turn this “weed” into liquid gold? Let’s get started.
Why Comfrey Makes Amazing Fertilizer
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Comfrey isn’t your average plant. It’s what’s called a dynamic accumulator, which is a fancy way of saying it has super powers.
That massively long taproot? It’s working 24/7 to unlock nutrients deep in the subsoil that other plants can’t even reach.
We’re talking potassium, phosphorus, calcium, nitrogen, and a whole range of trace minerals that are just sitting down there, unavailable to your shallow-rooted vegetables.
When we make comfrey tea (as it’s also called), we’re basically concentrating all those deep soil nutrients into a liquid form that’s immediately available to our plants.
The potassium levels in comfrey are actually higher than many commercial fertilizers, making this tea perfect for fruiting plants like tomatoes, peppers, eggplant, and fruit trees. That potassium helps with flower and fruit development, disease resistance, and overall plant health.
Plus—and here’s the kicker—it costs absolutely nothing to make after you’ve invested in your initial plants.
Getting Started: The Right Comfrey Variety
Before we dive into making the fertilizer, let’s talk about which comfrey to grow. This matters more than you might think.
I recommend buying comfrey crowns (root divisions) rather than seeds, specifically the Russian Comfrey variety. Here’s why: this variety doesn’t spread by seed, only through root division. That means you can control exactly where it grows instead of having it take over your entire property.
Trust me on this one—comfrey that spreads by seed can turn into a nightmare situation real fast.
Plant these crowns somewhere permanent because comfrey is practically indestructible once established. Ours line the south side of our pond, far from any water source, and they never get watered except by rain.
Drought tolerant, heat tolerant, perennial—this plant just does not quit.
Step-by-Step: Making Your Liquid Fertilizer
Harvest at the Right Time
Start with mature comfrey plants (at least 2 years old). I waited until this year to harvest from ours because I wanted those roots really well established first.
The best time to harvest is morning after the dew has dried. You want nice, healthy, dark green leaves. Don’t worry about being perfect—stems, flowers, even bugs are fine. They’ll all break down in the process.
Chop and Prep
Tear or chop the leaves into smaller pieces. This isn’t about perfection—just breaking them up to speed the decomposition process.
If you’re short on time, you can skip this step entirely and just wait an extra 4-6 weeks for your fertilizer. But chopping cuts the wait time to about 3 weeks.
Add everything to a 5-gallon bucket or any container that can hold water. Old litter containers work great—just make sure you have some kind of lid.
Add Water and Wait
Completely submerge all the leaves with water, then add more. Fill the bucket about 3/4 full. Rainwater is ideal, but regular hose water works fine unless you’re on heavily chlorinated city water.
Put a lid on it (even a piece of metal sheeting works) and let it sit outside in the heat for 3 weeks. The heat speeds up the decomposition process, so don’t bring it indoors.
Strain and Store
After 3 weeks, scoop out all the solid material with a strainer or large spoon. Those solids don’t go to waste—toss them right in your compost pile.
Pour the liquid into jugs and LABEL THEM. This is crucial because this concentrate will burn your plants if you use it straight.
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How to Use Your Comfrey Fertilizer
Dilution is Key
Always dilute at a 1:10 ratio. I don’t measure precisely—I just eyeball about an inch of concentrate in the bottom of a milk jug, then fill the rest with water.
Application Schedule
I treat this like my fish fertilizer and apply every 2 weeks throughout the growing season. This year I’m planning to use it primarily in mid to late summer to see if I can replace my store-bought fish fertilizer entirely.
The NPK ratio isn’t balanced like commercial fertilizers (which are artificially concentrated). Comfrey tea runs somewhere in the 2-0.5-5 range—much heavier on potassium than nitrogen or phosphorus. That makes it especially good for fruiting plants.
What to Feed
This works as a multi-purpose fertilizer, but it really shines on:
- Tomatoes and peppers
- Eggplant and squash
- Fruit trees
- Any plant focused on flowering and fruiting
Why This Beats Store-Bought Fertilizer
Beyond the obvious money savings, comfrey fertilizer gives you control over exactly what goes on your plants. No synthetic chemicals, no mystery ingredients—just concentrated plant nutrition straight from your own backyard.
You can harvest comfrey 3-4 times per season, and the more you cut it, the more it grows back. So making fertilizer actually helps the plant produce even more leaves for next time.
One plant will give you harvest for decades to come. It grows in most soil types and actually improves your soil structure over time. We’re talking about a investment that pays dividends for years.
The Bottom Line
In a world where everything costs more and quality seems to matter less, being able to make your own high-quality fertilizer feels like a small victory.
Your plants get better nutrition, your wallet stays fuller, and you’re building real skills that make your family more self-sufficient. That’s what we call good stewardship.
Ready to start growing your own fertilizer factory?
Grab some comfrey crowns this spring and start building your supply. Your future self (and your grocery budget) will thank you.
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