I felt very lucky to spend this past week vacationing with my family on Hilton Head Island.
I recently started selling my favorite organic liquid fertilizers, the same ones I use at home.
But I also like to make my own homemade liquid fertilizer when possible, and that’s what I’m excited to show you today.
Many of our best liquid fertilizers come from the ocean.
But there are ways you can approximate them, if like me, you don’t live near the ocean.
All of these can be used as a liquid lawn fertilizer, liquid plant fertilizer and liquid soil fertilizer.
You might even make enough for multiple applications (such as monthly or weekly).
For all of these homemade fertilizers, I suggest mixing with at least 10 parts water before you spray.
That will allow the fertilizer to cover more area, and will ensure we don’t burn our plants.
And it certainly doesn’t hurt to mix with even more water...
Liquid Kelp Fertilizer (Or Another Option If You Don’t Have Kelp)
Seaweed makes one of my favorite liquid organic fertilizers.
It’s special because it has natural plant growth regulators that promote all kinds of important plant processes.
Plus it has most of the minerals that are found in the ocean.
So if you live near a beach with seaweed on it, you can use that - just make sure to leave some on the beach, because it’s important for many organisms there.
But if you don’t live near a beach, you can use weeds and grasses from your garden instead of seaweed.
To make this liquid fertilizer, pack a container with seaweed or whatever you’re using, fill it with water and cover with an airtight lid.
Let it sit for a couple of weeks - or as long as a couple of months if the temperature is cold - until a lot of the seaweed dissolves into the water. If you’re using herbs, they won’t all dissolve like seaweed does, but somewhat.
It will smell really bad at first, but once the smelliness has decreased, it’s ready to use.
Spray it on your plants until they’re dripping, and onto the soil, too.
Don’t want to do all the work to make this homemade liquid fertilizer? Just spread the seaweed on your soil as a nutritious mulch that will break down quickly, releasing its nutrients.
Grass and weeds work as mulch too, but grass shouldn't be spread too thick or it can block airflow to the soil.
If you don't have (or want to use) seaweed or grass/weeds as mulch, check out the liquid kelp fertilizer I use.
Using Ocean Water (Or Another Option If You Don’t Live By The Ocean)
If you live near the ocean, you have an awesome fertilizer right at your doorstep.
Ocean water contains over 80 minerals that are immediately available to plants upon application, plus some beneficial biology, too.
You can go pick up some buckets of seawater and use it right in your garden.
I know it seems like it would be too salty, but research has been done on this for many decades with great results.
In the research they actually used 1-3 liters of ocean water per square foot of soil, and they figured out that it would last 5 years. Wow!
I’m much more conservative with my recommendations. I say more like 1 teaspoon per square foot of soil, which is 5 liters per 1000 square feet, and I say spray this 4 times per year onto your plants and soil, every year.
If you don’t live by the ocean, but you have a relatively unpolluted pond or river nearby, you can use the water from there. Of course it doesn’t have anything close to the mineral content of the ocean, but it does have some minerals and some biology and would be well worth the trip to pick some up.
Or for a simpler option, check out the concentrated ocean water fertilizer I use.
Making Liquid Fish Fertilizer
Ocean fish are preferred for this because they’re the ones that are loaded with nutrients.
But if you have access to fresh water fish, you’ll definitely still get some benefits.
What you want to do here is put the fish in a strong food processor to grind it up, bones and all.
Add a little water, blend some more, and you have a basic fish fertilizer.
But to get a better fertilizer, add probiotics and sugar to the mix at 1 teaspoon of each per cup of fish water.
I use effective microorganisms for my probiotic, but if you have yogurt or kombucha or some other live culture, that will be a help as well. I use any kind of sugar for my sugar - white sugar, brown sugar, icing sugar, molasses, whatever.
Blend that all together, put it in a container with a lid on loosely (so the gases that will form during fermentation can escape), and let it sit for a month or two.
The reason to take this extra step is because the microorganisms in the probiotic will break down the fish so that it becomes more usable by plants.
The mixture will smell bad at first, but that will partially go away by the end - that’s how you know when it’s ready.
Strain out the few remaining bones, mix with water, and spray away on your plants and soil.
Don’t want to do all the work to make this homemade liquid fertilizer? Just bury a fish (or part of a fish) under each plant when you do your planting.
Or check out the liquid fish fertilizer I use.
Certain forms of sugar can also be really useful in the garden.
Sugar feeds microorganisms, which can then get to work doing all of the great things they do for us in the soil and on plant surfaces.
My two favorite types of sugar for fertilizing the garden are molasses and dextrose.
But if you don’t have them, just take whatever kind of sugar you have, just like we did when making the fish fertilizer above.
Use perhaps ¼ cup of that sugar per 1000 square feet of garden.
Even a can of Coke per 1000 square feet of garden can be really helpful. It actually has a few ingredients that, though while not good for us to drink, are really useful in the garden.
So mix some sugar and/or Coke into some water and spray it on plants and soil. I know it sounds a little wacky, but it’s a great thing to do.
Homemade Liquid Fertilizer Conclusion
Feel free to ask your homemade liquid fertilizer questions in the comments below :)
Or check out my more detailed organic fertilizer guide.