By: Garden4Dinner

The last time I made my own seedling soil, my seeds did not grow very well. The only success I have had is using a Burpee peat pod kit with the included liquid fertilizer. I now know I did something wrong when I made my own soil, but I still don’t know what.

This fall I got a soil test on my garden beds. The results inspired me to pay attention to my seedling soil more. My garden beds contain a high amount of compost, but are missing some necessary nutrients.

Soil Test

This time I did a soil test. I used a soil test kit I bought at a hardware store. I actually have 2 soil test kits and this Rapitest Soil Test Kit is my favorite because it is easier for me to compare the colors. The color indicator is on the tube. Additionally, I like that the same tube is used for the same nutrient each time because it is labeled.

My results were surprising.

soil_test Seedling Soil Test

I was glad I did the test, because my high compost seedling soil is definitely nutrient deficient. My results were:

  • PH – Neutral
  • Nitrogen – Low
  • Phosphorus – Very Low
  • Potash – Medium

The hard part is determining how to correct the problem. I need a liquid fertilizer, because I need very small amounts for the seedlings. I read that seedlings only need 1/2 of the amount of fertilizer as other plants. The liquid nitrogen that I use will be diluted enough not to burn the plants.

Choosing Fertilizer

I had dry fertilizer but I didn’t have liquid fertilizer. I decided to purchase Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon, and Alaska Morbloom Concentrate 0-10-10 Fertilizer, 1 gallon, and I already purchased earlier this year  Jobe’s 09326 Organic Bone Meal Granular Fertilizer 4-Pound Bag . These should allow me to get the ratios I need.

fertilizer The Fertilizers I used for Liquid Fertilizer for Seedlings

The Bone Meal is not a liquid fertilizer, but I have read that I can make it from Bone Meal.

Liquid Bone Meal Fertilizer

I then made liquid bone meal fertilizer. I thought that if I added some water and put it on the stove on medium heat and waited for the bone meal to dissolve, I could use it as liquid fertilizer. I would say my experiment was only partially successful. A lot of the bone meal dissolved into the water, but there still was some sediment after cooking for 30 minutes. I may not have been patient enough, but it seemed like it would take a lot longer before it would actually disintegrate. I don’t even know if it would fully disintegrate.

bone_meal_liquid_fertilizer Bone Meal Liquid Fertilizer Cooking

I decided to use it anyway, so we will see how successful it is.

In a future post I plan to show how I calculated the amount of liquid fertilizer to add.

Mixing the Fertilizer

A few days later, I mixed up the fertilizer. Just a word of warning, this should be done outside. The fish emulsion fertilizer is especially smelly. I saved a milk jug from this morning, cleaned it out, measured the weight of the ingredients, and placed them in the milk jug. I filled the milk jug up to the top with water to make 1 gallon of fertilizer. This produced fertilizer to apply 2 Tablespoons per every 2 inch peat pot. This gallon of fertilizer should be enough for 3 of my 2 square foot flats. I then applied the fertilizer to the soil for my onion seeds. I made sure to shake often when applying the fertilizer because of the bone meal sediment.

mixed_fertilizerFinished Liquid Fertilizer

Seedling Soil Test

I waited a week to do another soil test to see how my fertilizer did. The results were pretty good.

  • PH – neutral 7.0
  • Potash – adequate-sufficient
  • Nitrogen – sufficient-surplus
  • Phosphorus – depleted

I was a little surprised the level of Nitrogen was so high considering I tried to go on the light side of application. I wonder if the Nitrogen is high because the pots are not very deep. The Potash and PH level are good. For the Phosphorus, I am not too surprised. This is about what I expected after the liquid bone meal did not turn out as well as I had hoped. It looks like I need to add a little phosphorus. Phosphorus helps with root development so I will make sure to try to fix this for the next seedlings. I plan to leave the other nutrients alone.

seedling_soil_testSoil Test after Amendment

Amendment Choice

In an attempt to be frugal and reuse some Bone Meal fertilizer I already had, it didn’t work out. I plan to purchase Liquid Bat Guano Fertilizer to help with my low phosphorus.


  • Soil test: 8 minutes (not including waiting time)
  • Mixing the seedling fertilizer: 15 minutes
  • Bone meal fertilizer: 5 minutes (not including the waiting time)
  • 2nd Soil test: 32 minutes (not including the 40 minute wait time, I did another soil test at this time)

(These are the materials I would get if I did it again)

Total cost: $51.38
Total time:
60 minutes

Have you made your own liquid fertilizer for seed starts? Was it successful?

[Image Credit: ©2017 Garden4Dinner]