adding fertilizer to seed starting coir.

Greatgardens · April 17, 2018

**IF** you were going to add a small amount of dry organic fert. to a coir seed starting mix, what would it be? I'm looking for a bit of "insurance" since I typically let my first plants get very large before going outside. For example my Rejina Red plants are now a full foot tall.

My initial thoughts are Burpee Bone Meal. 6-8-0 or one of the others that is typically 0-10-0, but leaning to the Burpee. Or can you suggest something you think might be better?

BTW, I've done "no additions" for many years -- I'm looking for potential improvement.

-GG

Al@NC · April 17, 2018

I put a dry slow release fertilizer in my dixie cups in the bottom 80% of the potting soil. Then add jiffy mix sterile to the top 20% of the cup with the mindset that once the seedling is growing it's roots deep enough in the cup it hits the fertilizer and it will take off. I have used all sorts of different ferts such as Osmocote in the past without giving much thought to which one to use though.

I'm curious as well about others that may add ferts to the seed starting mix...

Al

Father'sDaughter · April 18, 2018

Personally, I prefer to wait until seedlings are getting their first true leaves, then I start with a 50% strength liquid fertilizer with every other watering.

I used to use Neptune Fish/Seaweed Emulsion, but the smell gets pretty bad indoors. I now use the Vegetable formula from The Urban Farms (the Texas Tomato Food company). I start seeds in DE and up-pot to 100% coir, so my medium provides nothing on it's own.

Greatgardens · April 18, 2018

So in your use, multiple liquid fert. additions instead of a "permanent" one-time dry addition?
GG

AlittleSalt · April 18, 2018

Just a comment about fertilizing - I wait until the tomato plants have four true leafs and are 3 - 4 inches tall. I don't use coir, so I can't offer thoughts there.

Father'sDaughter · April 21, 2018

Quote:

Originally Posted by Greatgardens

So in your use, multiple liquid fert. additions instead of a "permanent" one-time dry addition?

GG

That is correct. They stay on the every-other-watering at 50% strength fertilizing schedule until they go out to the garden. It has worked very well for me so I stick with it.

bower · April 21, 2018

I have no experience with coir, but I can vouch for bone meal as a fert for seedlings, at least, here where it's cold it seems to work fine. As Al said, mixed into the bottom 80% or so is best, just because I find that fert on the top tends to promote wierd fungal stuff to grow.
The bone meal here is 4-12-0 iirc so some N as well as P. IMO the high P helps the cold situation by ensuring soluble P that's easier to take up in the circumstances. But liquid fish fert would provide that too, if watering works for you. I can't really water on a schedule here because I don't control the temperature and rate of uptake, and I want to keep the seedlings on the dry side not cold and wet.

It's possible that there's a better more balanced dry fert available with some K in it as well, but I don't know it or haven't tried.

Oh, and as regards the timing - I don't use ferts on the heat mat when germinating, but I put a few grains of bone meal into the cell pack and pot up the seedlings in 9 cells until they get a couple sets of true leaves. I've never seen any adverse effect of giving them a little fert before they have true leaves, but I wouldn't want to do that for germination stage as it might promote rots in the hot wet environment.

hl2601 · April 22, 2018

Thanks for your insights Bower and Al-
I have used osmocote sprinkled over the tops after transplanting generally with very good success. However-I see what you are saying about the issue of fungal diseases as possibly problematic. Never even considered that before. Also never thought of your solution to mix it into the bottom when transplanting. Love learning here!

April 17, 2018	#1
Greatgardens Tomatovillian™ Join Date: Feb 2010 Location: Indiana Posts: 1,124	adding fertilizer to seed starting coir. IF you were going to add a small amount of dry organic fert. to a coir seed starting mix, what would it be? I'm looking for a bit of "insurance" since I typically let my first plants get very large before going outside. For example my Rejina Red plants are now a full foot tall. My initial thoughts are Burpee Bone Meal. 6-8-0 or one of the others that is typically 0-10-0, but leaning to the Burpee. Or can you suggest something you think might be better? BTW, I've done "no additions" for many years -- I'm looking for potential improvement. -GG Last edited by Greatgardens; April 17, 2018 at 01:48 PM.

April 18, 2018	#5
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	Just a comment about fertilizing - I wait until the tomato plants have four true leafs and are 3 - 4 inches tall. I don't use coir, so I can't offer thoughts there. Last edited by AlittleSalt; April 18, 2018 at 01:17 AM. Reason: missing letter

April 21, 2018	#7
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	I have no experience with coir, but I can vouch for bone meal as a fert for seedlings, at least, here where it's cold it seems to work fine. As Al said, mixed into the bottom 80% or so is best, just because I find that fert on the top tends to promote wierd fungal stuff to grow. The bone meal here is 4-12-0 iirc so some N as well as P. IMO the high P helps the cold situation by ensuring soluble P that's easier to take up in the circumstances. But liquid fish fert would provide that too, if watering works for you. I can't really water on a schedule here because I don't control the temperature and rate of uptake, and I want to keep the seedlings on the dry side not cold and wet. It's possible that there's a better more balanced dry fert available with some K in it as well, but I don't know it or haven't tried. Oh, and as regards the timing - I don't use ferts on the heat mat when germinating, but I put a few grains of bone meal into the cell pack and pot up the seedlings in 9 cells until they get a couple sets of true leaves. I've never seen any adverse effect of giving them a little fert before they have true leaves, but I wouldn't want to do that for germination stage as it might promote rots in the hot wet environment. Last edited by bower; April 21, 2018 at 02:38 PM. Reason: add

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

April 17, 2018	#2
Al@NC Tomatovillian™ Join Date: Jun 2012 Location: Vernon, BC Posts: 720	I put a dry slow release fertilizer in my dixie cups in the bottom 80% of the potting soil. Then add jiffy mix sterile to the top 20% of the cup with the mindset that once the seedling is growing it's roots deep enough in the cup it hits the fertilizer and it will take off. I have used all sorts of different ferts such as Osmocote in the past without giving much thought to which one to use though. I'm curious as well about others that may add ferts to the seed starting mix... Al

April 18, 2018	#3
Father'sDaughter Tomatovillian™ Join Date: Nov 2011 Location: MA/NH Border Posts: 4,919	Personally, I prefer to wait until seedlings are getting their first true leaves, then I start with a 50% strength liquid fertilizer with every other watering. I used to use Neptune Fish/Seaweed Emulsion, but the smell gets pretty bad indoors. I now use the Vegetable formula from The Urban Farms (the Texas Tomato Food company). I start seeds in DE and up-pot to 100% coir, so my medium provides nothing on it's own.

April 22, 2018	#8
hl2601 Tomatovillian™ Join Date: Dec 2017 Location: Metro Denver Posts: 770	Thanks for your insights Bower and Al- I have used osmocote sprinkled over the tops after transplanting generally with very good success. However-I see what you are saying about the issue of fungal diseases as possibly problematic. Never even considered that before. Also never thought of your solution to mix it into the bottom when transplanting. Love learning here!