Making your own fish emulsion

You see, all plants require nutrients, which occur naturally in the soil. But there’s no such thing as perfect soil. Or soil that, over time, doesn’t become depleted and need to be replenished for plants to thrive.

FERTILIZER 101

Most fertilizers contain three primary nutrients: nitrogen, phosphorus and potassium. They’re represented by the N-P-K ratio on the bag or box. Nitrogen (N) helps plants channel their energy into green, leafy growth; phosphorus (P) encourages the growth of roots, fruits and flowers; and potassium (K) benefits a plant’s overall health.

Many fertilizers also contain secondary nutrients, such as calcium (Ca) and magnesium (Mg), and micronutrients like iron (Fe), copper (Cu), boron (B), manganese (Mn), zinc (Zn) and molybdenum (Mo). All are necessary for optimal plant growth.

The good news is they don’t have to come from a box, bag or a bottle.

Hey, fellow gardeners! There are many ways that you can save money while providing your plants with high-quality For example, fresh grass clippings: Consider allowing them to remain on the lawn after mowing. Doing so can eliminate the need for chemical fertilizers. As they break down, fresh clippings release nitrogen into the soil that will sustain your lawn. I don’t recommend using fresh clippings in garden beds because they attract slugs.

Then there’s compost, which is the single best soil amendment available. If you have sandy soil or volcanic ashy soil, compost increases its ability to retain moisture. For clay soil (archeologists often refer to our native soil as “butter clay”), compost improves clay soil’s drainage. Plus it adds beneficial nutrients. Incorporate generous amounts into veggie, flower or herb beds.

If making compost isn’t your thing or if you don’t have room for bins or tumblers (they don’t work well in Kodiak’s climate, anyway), there’s no need to buy it. Simply collect kitchen scraps (coffee grounds, vegetable peelings, apple cores, egg shells, etc.) in a container on your countertop or under your sink.

When it’s full, head outside to dig its contents into the garden. That’s right, Dig and Drop: Dig a hole 8-12 inches deep, drop in the scraps, then cover it back up. As the bits of orange peel and carrot tops decompose, they’ll add valuable nutrients to the soil. You can bury food scraps, including the occasional salmon carcass, between rows of veggies or among larger plants.

I can hear the uproar now, “But Marion, my dog will just dig ’em up!” And I say, “don’t blame the dog.” If your, or your neighbor’s dog, digs in your garden then some preventive measures need to be put in place, whether it’s a fence, fishnet barrier or... hello... training. 

Many gardeners treat their plants with fish emulsion, Alaska Fish Fertilizer being a local favorite. Fish emulsions are basically an organic, fast-release liquid fertilizer made from whole fish and byproducts from the commercial fishing industry. It contains nitrogen, phosphorus, potassium, calcium, magnesium, sulfur and sodium, among other nutrients.

Fish emulsion can be a little pricey to buy, plus it lacks microorganisms important for soil and plant health.

Plants appreciate a wide array of fish-based feeding, including a whole salmon (OK, it had been in the river a while and was not fit to eat) placed at the bottom of a planting hole. Or homemade fish emulsion.

All you need is a bucket with a lid, mesh screen, sealable bottle, dried leaves, sawdust, or other carbon (brown) material, fish scraps, and water. (Adding molasses can help build up microbes that speed decomposition.) Here is how to make it:

I’ll be making my own batch soon, following this recipe. I’ll let you know how it goes...

Designate a five-quart bucket for the emulsion. It will always smell like fish after this, so you likely won’t want to reuse it for something else.

Collect your fish scraps (bones, skin, guts, etc.).

Layer them in with leaves and/or old sawdust until the bucket is two-thirds full (You can also start by lining the bucket with a bed sheet and then tying off the bag with string when you’ve added all the ingredients.).

Add 1 cup of molasses, preferably unsulfured (molasses with no additives).

Cover the mixture with fresh water, leaving a few inches of space on top of the bucket.

Seal the bucket and tuck it away. (Some references suggest sealing the bucket with a lid with holes to provide airflow. Would covering the bucket with a piece of plywood and weighted with a rock work as well?) Stir the mixture (or lift the bag) each day for two weeks. Or if you want to automate the process, hook up a simple “bubbler” pump to aerate it.

Let it sit for another two to four weeks. It will break down faster in warmer weather.

STRAIN THE MIXTURE

Once your fertilizer mixture is done steeping, lift out the bag or strain out any solids with a fine metal screen (an old window screen works well) and save the liquid in sealable bottles or jars. 

To use the homemade fish emulsion, here’s where sources really diverge. I’ve seen the ratio vary from diluting 1 tablespoon to 1/2 cup of the concentrate into 1 gallon of water before applying the fertilizer to plants.

If using an oily fish such as salmon or herring, I’d probably stay on the side of caution, adding just 1 or 2 tablespoons of the concentrate to a gallon of water. Perhaps doubling the amount of concentrate if halibut or rockfish is used.

HOW TO APPLY FISH FERTILIZER EMULSION

Use a watering can to apply the diluted fish emulsion fertilizer to your raised beds, containers, hanging baskets, tomatoes, cucumbers, or overall garden as a soil drench. To encourage your plants (or lawn?) to absorb the fertilizer, water the soil immediately after fertilizing.

When feeding plants such as nasturtiums, strawberries and peas, cut the concentrate in half. Otherwise, too much nitrogen will encourage big leaves and fewer flowers, fruit or veggies.

Don’t get rid of the leftover scraps. Add more water to the bucket and start the process again. You can typically use used material about three times.

I recently learned of the benefits of watering plants with a homemade yeast brew. But that’s another column.

Meanwhile, try making your own fish emulsion and let me know what recipe you end up following. 

The best part is that we have another way to use fish scraps!

Check out my YouTube channel. To find it online, copy the following name and paste it in your browser: youtube.com/ItsNeverTooLate. Meanwhile if you have a garden question, get it off your chest! mygarden@alaska.net.