Growing onions DWC

[Prybar]

I am 63 and very new to hydroponics.
I own a restaurant sports bar.
Because of the food situation in the country. I grew all my vegetables outside this sumer. This was an edge!
Now taking it indoors to keep it going.
What a learning curve!

My onions are my only DWC system.
The rest of my units are all RDWC systems.

I took a 2 x 3 cement mixing tray about 8 inches deep.
And a one inch thick piece of Styrofoam which I drew a graph on 3 inch centers.
Then took a big countersinking tool in a drill and just popped it through the other side. Makes a cone shaped hole.

I grow scallions for the green stem to garnish some appetizers. Just saying.

Frost killed the onions. I dug up about 125 of them. Cut the tops off. Washed the roots off and trimmed. Stuffed them in the hole.

The foam board floats on the nutrient water with 2 air stones underneath.

One week, they are 3" high, kicking it!

Has anyone tried this. The pic is the day I put them under light.

[pepperhead212]

I grew scallions last season for the first time in hydro, and surprisingly, they got covered with black aphids, yet I never have this problem with them outside, and as soon as I pulled them out, the aphids disappeared from the other plants. And I never had this problem with chives or garlic chives. Same thing with spearmint, even though peppermint is totally immune to the aphids in hydro. Had this problem with some herbs with spider mites, too, only in hydro.

I save the lower 3/4" of scallions all the time, and use them as sets! And I often cut out a cone from the root end of large onions, and use those as sets. I wish they did better in the hydro - I hope yours do better.

[Prybar]

Thanks. Sure hope I don't get bugs.
How soon into growing did you notice?

[Prybar]

Forgot to ask you. Was it in a tent or room.
Thanks for sharing your experience.

[applestar]

I’m a complete hydro neophyte and don’t know the terms, but I dabble with aquaponics experiments and have been growing scallions/green onions in I think “flood and drain”? Is that the right term?

In the ground, scallions and bulbing onions (roots) are very susceptible to overwatering and soggy soil, but are dependably drought tolerant especially if not completely dried out but have access to slight dampness/moisture.

I suspect they would grow well in the kind of set up with root misting rather than soaking in water.

[pepperhead212]

Forgot to ask you. Was it in a tent or room.
Thanks for sharing your experience.

That's just down in my basement - no tent - with some long, 4' LED lights. Two DW systems, each with an airstone and small powerheads, with some sponge filters.

It was quite a ways in when I noticed those aphids, like after I had harvested some already.

[Prybar]

[/img]Today's update on the onions. Today they are 7 days old from planting.
Pics

[Prybar]

Also today I noticed some tips had got burnt so I moved it up, 6.

[Prybar]

Here is today's pic. Exactly 2 weeks and ready to harvest.
This was my first dwc. Now I will expand.

That is only enough for one week.
I'm thinking a full 3 x 3 tray now, with holes closer together.

[Prybar]

Two weeks ago.

[imafan26]

Looks good. Onions grow very fast in water.

[Prybar]

This is the chamfering tool that I use in my drill, for making onion holes. Works perfect, keeps light out from starting algae.

[pepperhead212]

I like that idea for the "cone" cutter for the Styrofoam. What size hole do you make at the bottom, or the output side? I can see using that for some smaller things, as well as onion sets. Most of the things I grow need the larger baskets, however.

[Gary350]

If you only grow onions for garnish maybe you should grow Winter Onions outside, also known as Egyptian walking onions. These are zero maintenance, plant sets 2" apart then walk away and never look back. These onions grow good in full sun in freezing weather, snow & ice does not kill them. My relatives in IL & MI grow them. My grandmother grew winter onions near the back door, if she needed onions she pulled some up then crumble the tops to let sets fall, where ever sets land is where they grow.

Cut the tops off they keep growing back. There is no need to ever pull up these onion plants just leave them to grow tops and new sets. Each onion plant will grow about 50 onion sets. I bought 100 sets and 1 year later I had 4000 onion plants. I gave away most of the sets if I had planted 4000 sets it would have grown 160,000. more onions. There seems to be different varieties of Winter Onions some have stronger flavor than others. The variety I have are mild flavor they look good and taste good too.

I planted 125 onions in the garden in a 2'x2' square location next to 98 garlic. Flower pot on the right has 100 onion plants in it. Pot on left has about 30 or 40 onions in it. I only planted onions in pots to keep sets from dying, they need a new home some time soon. It is 29° this morning and going to be 6° and snow next Friday morning.

[imafan26]

Onions are cut and come again. You can keep picking off the tops and they will grow start growing back in days. The only downside is that as the onions get older the greens will get fatter and tougher. While it is o.k. to cook with the tougher greens, garnishes are better with the thinner leaves. Try growing chives in DWC, they taste a little different but they do not get fatter as they age. Or you can grow green onions from seeds and replace the old ones when they get too fat. Gren onions from seed are slow to grow so they need a good head start.