Starting seeds

[ken harmeyer]

What is the best way to start seeds?  I know you can't start them in dirt as you would normally do, so what do you use.  I live in Honolulu so I can run my system year round. I don't want to buy anything more, I don't have the storage space.

[Alex Veidel]

What style of aquaponics are you doing? Media? DWC? If you're doing media based aquaponics, you can just plant the seeds directly into the media, at whatever depth is recommended for the seed (usually about twice as deep as the seed is wide). Other than that, a lot of people use vermicompost (worm castings), coconut coir, vermiculite, or a combination of all three. You can even start your seeds in dirt, then wash them and transplant into your system. I personally either sow directly into media, or start in vermicompost.

[ken harmeyer]

I am using volcanic cinders.  They are light and about as big as large gravel. I am afraid if I put the seed directly into the cinders they would float away. Strangely enough, dried coconut is hard to find around here.  Do you start the plants in vermiculite and jiffy pots? Then plant the whole thing?  Or do you start a bunch of them in a pot and take them out and put them in the cinders?

[Bianca LoBue]

I suggest not to put them straight into the media, not to say that it doesn't work, but the risk you run is exactly what you think. What are you growing? Each plant has its own way of germination. Here is a good web page to start your propagation.. 

http://grow.ars-informatica.ca/index.php

[Roger Baldwin]

I have had good luck sowing straight into my media. In fact I planted more seed than I needed, to increase my chances and it seems like everything has had a very high germination rate. So, I have had to do a fair bit of thinning and transplanting. Also it is amazing how well bare root transplants take in a media bed. I planted way too many cucumbers and had to thin them so I just pulled the the plants out when they just had their cotyledons developed. I transplanted two into another AP media bed and 5 into a soil bed. The 2 in the AP didn't even wilt before they took off and they are just as vigorous as the ones that didn't get thinned. Out of the 5 in the soil 3 might make and they are way behind. So if you don't want to sow direct, then any form of transplant would work IMO, but I would would limit the amount of decomposable material you add.

[Alex Veidel]

Are you using continuous flow or a flood and drain based system? If it is a flood and drain, then your water line should be rising a few inches below the surface of your media, leaving a couple inches of dry media. That will take care of the seeds not being anchored. I just have a tray of vermicompost with seeds planted in it, like you would a tray of soil. Then you pull out the seedlings and transplant them into your media.

ken harmeyer said:

I am using volcanic cinders.  They are light and about as big as large gravel. I am afraid if I put the seed directly into the cinders they would float away. Strangely enough, dried coconut is hard to find around here.  Do you start the plants in vermiculite and jiffy pots? Then plant the whole thing?  Or do you start a bunch of them in a pot and take them out and put them in the cinders?

[Pat James]

I am setting up a raft system and am going to start seeds in vermicastings.  I figure that as the vermicastings are washed out of the net pots and into the system, it is a purely organic material that will neither settle out or bog any of the system.