Backyard Aquaponics
A place to discuss aquaponics

I'm hoping to use my indoor system to get some seedlings going for our outdoor garden. I was trying to figure out the best way to do this. It seems like transplanting might be difficult because when the plants' roots come out of the water, they will all become one long hanging root mass, not spread out like they should be for growing. So I was thinking that I should grow them in some kind of media in pots so that they can be transplanted in the media into the dirt. Would shell grit be good? Does anyone have experience with this topic? Can you tell me how you did it

I haven't grown seedlings in AP for transplantation but I've planted plenty of cuttings that have been growing roots in a bucket of water, planted seedlings I've washed the soil off the roots and so on. You just have to be gentle when transplanting and carefully spread the roots out a little. As with bare rooted plants, I generally try to make a little mound in the hole to spread the roots down over. Seems to work, and I can't imagine it'd be overly different from seedlings in an AP setup given you're essentially planting the same thing.

Buy rockwool cubes.
Dont let the roots get too large, not hanging too far out of the cube.

Transplanting from AP usually has a 100% failure rate, however if do it early enough, then it may work.

Larger plants are used to much, much more water and wilt and die very quickly after being put into dirt, even with twice daily waterings.
I havent transplanted a lot of plants, nor every type, but the ones i did all failed and i have heard of no success stories.

That's surprising, I wouldn't have thought it would be such a failure. What do you put it down to? I really wouldn't have thought it would be much different from a cutting rooted in water.

I suppose a lot of it would be transplant shock, but I'd have thought going from soil to an AP system would be more of a shock to a plant, and that so far I've had complete success with. It is interesting that it doesn't seem to work though.

Hmm, I'm tempted to pull a few of the seedlings out of my barrel system, stick them in the ground and see if I can work out where the problem lies.

What about weaning them off of the high water levels somehow before transplanting? Or having a flood and drain system that has a long time between floods?

In commercial AP systems seedlings are typically started in trays with a soilless potting mix of 60/40 percent coconut coir/vermiculite and fertilized 2-3 times weekly with a 9-45-15 fertilizer to promote good root growth. Well, according to Dr. Rackoy anyway.

I've tried starting seedlings directly in my DWC bed in 2" net cups with Oasis root cube media with poor success. I've since switched back to using trays outside my system.

Well i am utterly surprised by this thread, i have been growing all my seedlings up until last week in my DWC and recently switched to using a shallow tray with AP water due to lack of space in the rafts.
I 3/4 fill the pot with vermiculite, sow seeds, then top up with perlite, same for DWC and shallow tray and i was using the shallow tray technique for many weeks pre having the DWC online.
I then transplant the seedlings to either their own pot in the DWC, or into the GB's or into my organic dirt garden.
Granted i do loose the odd few, and intact last weekend lost half my transplant to the dirt but only due to my negligence in by transplanting around lunch time on a warm day into fresh organic mulch that was too hot, but i was in a rush and paid the price.
Generally i do the transplant late in the evening and give them a soaking so they have all night to recover, and where possible i leave as much of the vermiculite/perlite around the roots as i can.

This seedling raising technique i have found to be much easier than dirt raising and love it.

As i stated above, transplanting seedlings may be just fine, but larger plants are used to a certain amount of water and it is a huge shock to no longer have that constant supply.
weening the plants may work too.

Alternatively you can use the shallow tray technique but use good draining potting mix, that is how i started but got sick of washing roots pre transplant to GB's.

Kitacooch... Could you explain what you mean by shallow tray technique. Also, I was hoping to grow the seedlings pretty big before planting out. Do you think that will work? I might try a few different approaches to do my own research.....hmmm

When i say shallow tray i mean i use a tub, place in my cace about 5mm of AP water in it. Then i have tray that is like a plastic mesh that i place my seedling raiser cups in so i can then lower the tray into the tub with the water in it.
Everything stays moist with rich AP water. Will take a pic over the weekend and post for you.

Give it a go marg, cant hurt to try.

It's easy to transplant from soil to AP but difficult to go the other way. I believe there is a difference in the roots that develop. Going from soil to AP, water is readily available, giving the plants the time they need to shift, going from AP to soil doesn't. Kitacooch's way makes sense. I haven't tried vermiculite but I think it would work for the switch to soil and that's what I would try. Avoid inhaling the dust. I'd do the transplant as Kitacooch does, in the evening and leaving as much vermiculite on the roots as possible followed by watering. This will help to keep the roots from sticking together, will keep water near the roots, and will give them overnight to begin acclimatizing.

I mostly go from soil to AP because the AP water is pretty cool here in the Spring and it's easy to get seedlings going in seedling mix on a heat mat. I suppose I could try using a tray of vermiculite on the heat mat instead.

Here is my seedling raiser, these are densely sowed as they all going into the AP, when raising for dirt garden i sow more sparingly.

I dont think ive managed to transplant a single thing from AP back to dirt.. The shock kills it