The best organic fertilizer for seedlings is also the simplest, worm castings. Learn the exact super simple method I use to fertilize my houseplants, my seedlings and starter plants with worm castings.
It takes all the risk of over fertilizing away and ensures your plants have an abundant supply of balanced nutrients to access as they need it.
Potted Starter Plants Will Run Out Of Nutrients
Growing indoors over the winter and/or also starting your plants indoors for your outdoor garden can be tricky. The plants, in their tiny little pots, will eventually run out of nutrients vs a plant growing right in the soil outdoors. Outside in the ground they’re exposed to a lot more soil (nutrients) and moisture. It’s a very different story than in those tiny little pots.
The Result Of Lack Of Nutrients
We need to make sure we’re giving them what they need to grow without delay, being stunted and to survive transplant without too much shock once you transplant them outside. You want them to not skip a beat and go on to be strong healthy, vigorous plants that produce well for you.
I will share both methods using worm castings and also alternative organic liquid fertilizers. Whether you can’t get worm castings or you don’t have enough, there will be times when you need to supplement with other options.
Worm Castings Vs Woom Poop Vs Vermicompost
They are all the same! You will hear all of these names used but they all refer to one thing, the poop the worms leave behind after consuming your compost materials such as vegetable scraps, plant matter or even suitable paper products.
This is the method of using red wiggler worms to consume organic matter and turn it into beautiful nutritious black earth that your plants are going to go crazy for. It is literal gold to a gardener. It is even more nutrient dense than standard compost using a bin.
This post is not going to be about how to make homemade fertilizer for seedlings by making your own compost or worm compost. I do have a very in-depth mini-course on those two methods as well as several others. I will link it here→ Your Essential Compost & Vermicompost Guide 2.0
This post is all about how to use the worm castings once you have it (whether purchased or produced yourself).
When you’re mixing up your soil for repotting plants or starting your seeds you will need a standard potting soil mix and worm castings. The ratio I used is not exact and that’s the beauty is it doesn’t need to be. It’s not instant release like a liquid fertilize which could shock and kill your plants.
Typically I mix into 1-3 ¼ cup scoops into about 4lbs of dirt. Vermicompost goes a long way (also why I love it).
For larger and more hungry plants I mix it a little on the heavier side. This would be for plants like peppers, tomatoes, pumpkins, cucumbers or anything that grows quickly and vigorously. I use this same mixture across the board, every time I increase the pot size, divide a plant, start seedlings. It has served me well in all areas of plant growing.
When To Start Fertilizer Your Brand New Seedlings?
Once your seedlings get past those first 4 leaves, the cotyledons and the first 2 true leaves, you can start to supplement additional worm castings through watering.
Add Worm Castings To Your Water
I add about 1 heaping tablespoon to a 2L watering can and let sit for the day or overnight and then water my plants with it.
Keep giving it a stir as you water and it will deposit a small amount in the pots as well as the nutrients that leached in the water will be absorbed in time by your plants.
This wouldn’t be considered a proper “worm tea” which also uses worm castings in water to water plants. Worm tea involves aeration, using a bubbler, of the mixture as well as a sugar for the bacteria to feed on and proliferate. This is more of a halfway step to full worm tea. It deposits the nutrients but doesn’t focus on the bacteria growth aspect (helps build even better soil).
You will find a full detailed worm tea tutorial in my composting course Your Essential Compost & Vermicompost Guide 2.0.
It’s very rare that I add in any extra supplementary fertilizers other than worm castings.
If You Run Out Of Worm Castings
If you feel like you don’t have enough compost or you don’t have access to any at all you’re going to want to look for an organic liquid fertilizer.
A water soluble fertilizer is key for your seedlings ie. it dissolves in water and you disperse it with your watering.
When you’re shopping for organic liquid fertilizer keep it simple (I will link a list to some great options here).
What Kind Of Fertilizer Should You Buy
Look for something that’s balanced in the nutrient numbers on the label. These 3 numbers are your nitrogen, phosphorus and potassium, or macros for plant nutrition. There are reasons to look for one nutrient higher than another such as more nitrogen to boost leaf growth etc but if you’re not very familiar with this it will cause you more complications and likely imbalance in plant growth. When in doubt , keep it simple and go for balance.
Be Careful With Fertilizers!
Liquid fertilizer is almost instant absorbed by your plants. This means extreme caution is in order. Less is NOT more in this case.
Seedlings especially when they are very small require no stronger than a 1-2 for the nutrient strength. If you can’t find a fertilizer with this you can dilute it down to this when watering. This is another reason I love worm castings. It’s a naturally slow release. You can’t shock your plants which means much less room for error.
Why Use Compost or Vermicompost First Always?!
Compost and vermicompost help retain moisture, creates fluffy soil that can breath well, and brings in lots of great microbes into the soil. The microbes are like little gatekeepers. They unlock the nutrients for your plants. So it’s a win win on all fronts. It’s easy, fool proof and benefits your plants in so many ways.
I am a broken record on compost and vermicompost. It turns my household yard and food waste into something super beneficial for my plants while reducing my households waste significantly.
My plants still surprise me sometimes as how well they respond to being planted in worm castings. They sometimes out run my ability to keep up with transplanting them. Which is pretty amazing!
Simplified Seed Starting Process
As a gardener growing in Zone 3A, which means starting a lot of my plants indoors, this keeps my plants happy, healthy, strong and saves me all the stress and headache dealing with plants that are behind, or die after transplant.
It has simplified my seed starting methods and the amount of attention I need to give my plants. All of this means I am a much happier gardener and find a lot more ease in the process!
So if I haven’t convinced you yet to start your own compost or vermicompost system then please reach out to me and tell me why you don’t think it is for you. I would love to know if there is a way I can help you find the perfect system big or small to get you going. It really is so beneficial to the environment through your reduced household waste and your plants with LOVE you! (PS it’s not stinky or gross.. not if it’s done right) Email me here and let’s chat → Info@themindfullivingmovement.com