Starter Media

[Ryan Chatterson]

I just wanted to get a better idea of what kind of starter media everyone uses to sprout seed... Rockwool? Coco fiber? Filter material? Perlite? Direct Sow?

I personally prefer rockwool cubes but have also used coco fiber in a small netting material for starts. I direct sow into pea pebbles or perlite beds and things work well.


Looking forward to seeing what you guys are doing :)

[TCLynx]

For large and/or fast sprouting seeds direct sowing has worked very well for me.

However, when I am lazy or if I need to start things indoors then move out, I've often used peat pellets or coir pellets which works well for transplanting into towers and beds alike.

I've also used trays of coco fiber for baby greens or shoots.

 

It all kinda works, just gotta figure out what works best for you.

[Rick Op]

Anything but perlite. I can start a seed in a cotton string and I don't have to worry about it blowing into the fish tank and getting eaten.

 

Usually I do direct sow, my medium is expanded shale which wicks water up a bit above the actual water line. And if a late spring Cold Front threatens, the seedlings can be pulled out of the loose medium and brought indoors no matter how big they've gotten.

 

If you're in gravel, you may want to employ a wick (like a mop string) to be the middleman between the seed and the water until the roots reach down far enough.

[Chris Smith]

I use lava cinder in 2" new pots. It is the cheapest media I can find and readily available when living on a volcano. The cinder has good wicking capability and will keep the seeds moist when the net pot is sitting in 1/8 inch of water. Since there are voids between the cinders, the roots get all the oxygen they need. I used to use coir and had poor germination rates at times. With cinder I get nearly 95% or better germ. Cinder is easy to recycle too.

[Greener]

I just bought a bunch of Botanicare CocoGro 5kg bales (each compressed bale expands to ~65-70L, or ~18 gal, when soaked.  This stuff looks great, and the best price I could find, by far.  Here's the description: http://www.sea-of-green.com/cocogro-brick-clone-2.html).  

 

I also bought 72-cell seed starter trays as well as 2" flats for microgreens/shoots.  The cell trays have holes in each cell, but I will have to drill holes in the trays.  These will sit on wicking mats, and I'll also use heat mats on cold winter nights.  I also got a number of the matching humidity domes, some 2" high and some 7" high, for cold nights.

 

I'm planning on starting with a coco & sand mixture, but I wonder if the roots will get enough oxygen this way.  I think they will be okay, but does anyone have advice about this?  One drawback is that clean sand is expensive (and heavy)!  OK I have only checked Home Depot so far, but dang!  (Also I found it hilarious that the sand package had images of kids playing in a sandbox, and the package said ideal for sandboxes, gardens etc.. but then RIGHT below the images of the kids there was a fine print disclaimer saying prolonged exposure to the sand dust could cause serious lung problems, maybe even lung cancer.. and then.. KEEP AWAY FROM CHILDREN.  Ha!  So, buy this for your kid's sandbox.. but DON'T let them near it!!  Wow.).

 

I was thinking of experimenting with coco and hydroton too.  I could justify buying a small amount of hydroton for seed starting, but getting enough for my GBs is out of the question.  Does anyone know how easily hydroton can be crushed into smaller pieces?  I think the balls might be just a little too big for my purposes.

 

My notes tell me to avoid perlite, rockwool and vermiculite, the dusts can be very bad for your lungs and the small particles that will inevitably get into your system can be very bad for the fish.  I doubt this is much on an issue in a big system without too much of the stuff in it, but still I will try to avoid it if I can.

 

I am very interested in seeing what media others are using for successful seed starting.  Thanks for sharing!

 

[Lon Wells]

Sand-dust can cause silicosis. Washed sand has the fine dust particles removed so it is safe in children sand boxes the added effort raises the cost.  Since aquaponic sand is covered with water the dust will not become air borngetting into your lungs because it is wet. Use a dust mask before you wet the sand and you will be safe.

Greener said:

I just bought a bunch of Botanicare CocoGro 5kg bales (each compressed bale expands to ~65-70L, or ~18 gal, when soaked.  This stuff looks great, and the best price I could find, by far.  Here's the description: http://www.sea-of-green.com/cocogro-brick-clone-2.html).  

 

I also bought 72-cell seed starter trays as well as 2" flats for microgreens/shoots.  The cell trays have holes in each cell, but I will have to drill holes in the trays.  These will sit on wicking mats, and I'll also use heat mats on cold winter nights.  I also got a number of the matching humidity domes, some 2" high and some 7" high, for cold nights.

 

I'm planning on starting with a coco & sand mixture, but I wonder if the roots will get enough oxygen this way.  I think they will be okay, but does anyone have advice about this?  One drawback is that clean sand is expensive (and heavy)!  OK I have only checked Home Depot so far, but dang!  (Also I found it hilarious that the sand package had images of kids playing in a sandbox, and the package said ideal for sandboxes, gardens etc.. but then RIGHT below the images of the kids there was a fine print disclaimer saying prolonged exposure to the sand dust could cause serious lung problems, maybe even lung cancer.. and then.. KEEP AWAY FROM CHILDREN.  Ha!  So, buy this for your kid's sandbox.. but DON'T let them near it!!  Wow.).

 

I was thinking of experimenting with coco and hydroton too.  I could justify buying a small amount of hydroton for seed starting, but getting enough for my GBs is out of the question.  Does anyone know how easily hydroton can be crushed into smaller pieces?  I think the balls might be just a little too big for my purposes.

 

My notes tell me to avoid perlite, rockwool and vermiculite, the dusts can be very bad for your lungs and the small particles that will inevitably get into your system can be very bad for the fish.  I doubt this is much on an issue in a big system without too much of the stuff in it, but still I will try to avoid it if I can.

 

I am very interested in seeing what media others are using for successful seed starting.  Thanks for sharing!

 

[David Waite]

I was using the coco compressed bales and my germination just sucked. About 50 percent on lettuce and 10 on spinach. I switched to peatmoss which is cheaper and my germination is a lot better. I dont like how wet it is in my rafts and the fact if its over the air stones they will bubble out the mixture sometimes. I am going to try a blend of Perlite and peat on the nextset of seeds. Like to rockwool concept but the 10 cent cost per is more than my cheap a-- wants to pay. What do you think of small shredded bark, has anybody tried this. Chris you should bag the lava and market it heehe. We cant get anything but red here and it just is a mess with water.

[Larry Hill]

My first batch of stuff I used a 50-50 mix of coir and vermiculite.  It worked pretty well, but the media got washed out of my net pots pretty easily if the bubbles hit it.

 

I switched many of the started plants over to small chipped marble.

 

My latest experiment, which I'll have to report back on is this:

 

Filled the net pot 2/3 with pebbles.  Then I made a wet paste of vermiculite in a small bucket.  I smeared a little on top of the pebbles, sprinkled my seeds in, then smeared some more vermiculite paste on top.  I'll be watching them carefully to see if the vermiculite stays moist - I might have to hand water a bit, or go with the pebbles lower in the pot so the vermiculite has better contact with the water and wicks better.

 

[TCLynx]

Add some rayon yarn as wicks and you may not need to worry about hand watering.  Goodwill mop heads (the bright white ones) have rayon stings that work well as wicks.

[Chris Smith]

I would love to bag and sell the cinders except it is bad joo joo to remove rocks from Hawaii. Rocks are constantly mailed back to Hawaii post offices after people brought them home and began having bad luck.

[TCLynx]

And if people were to send too many rocks off the Islands, they would be shrinking instead of growing pretty quickly too.