Growing root crops in media beds

[David Waite]

My system is about 26 weeks old as of sept 15 2011. I am having better than expected success with root crops. So far beets, onions, garlic, carrots and radishes all love the media beds. I think my success is partly to my gravel being round and not cracked. What successes or failures is other aquapons having. My system is flood and drain with affnan siphons. About 20 min cycles. My ph is at 7.8. I am having no luck with potatoes .That is the only root crop that has failed. Please be specific. Media type, cycle time, ect...ect.

[David Waite]

Allisyn thanks for the link. I think you are on the right track with the shorter variety. I too will order and plant this month. keep us posted on your progress.

Allisyn Wood said:

I found some carrots from Seed Savers Exchange.  They're Paris Market. They're shaped like beets and get 1-2" dia.  French Heirloom.  Says they do well in shallow or rocky soil.  50-68 days.  I have not planted them yet (going in the 15th) so I can't attest to how they grow, but it sounds like they might be perfect for our gardens. 

David Waite said:

Carrots are slow and growth rates are disappointing. Onions leeks and garlic are all positive. size ranges are all over the map from silver dollar to softball. The cabbage doesnt belong but it was part of the harvest. So for the discussion root crops continue to be very productive and worth growing. I have rudabaga and will update when its time to harvest. Part of my problem on carrots are high ph which they dont prefer. I am going to plant round two of all root crops and see how they do this fall. Hope to carry them over this winter and harvest all winter with minimal to no heat. The experiment continues.

[David Waite]

Well my root crops are at the end of the ropes. The carrots were really disappointing. Small and irregular in shape. Still in my first year only had the potato fail completely. Currently planting round 2 of garlic and carrots. I am switching to a shorter variety recommended by earlier post. The melon was part of the harvest and was a great success. The Leeks flavor is to die for. Rudabaga is on the list for next year. I am switching media this winter to help lower the ph. I will also install an RO to help with carbonates. Will keep you posted.

[Harold Sukhbir]

Hi David,

  

[David Waite]

Hey Harold planted some elephant garlic a few weeks back. Cant wait to see how they do. Each head is the size of a saucer. Should be interesting.

Harold Sukhbir said:

Hi David,

  

[Kobus Jooste]

Hello all root crop growers.  I would like to aske everyone if they have seen vastly different results based on the water flow patterns employed in their root crop beds?  I had flood and drain in the sand bed to start off with, and the beets were really not all that happy.  I started over, and added a surface distrubution grid over the unit, with a balancing valve on the outflow to ensure that the NFT does not overflow. The result is now that the bed only floods about half-way to the top at most, but the sand still gets a good wetting every hour.  The plant growth change has been immediately obvious.  I'm working on the assumption that a dry (relatively dry in any case) media with frequent surface trickling is much better than traditional flood and drain.

[David Waite]

Kobus my beets really did well with 20 min flood and drain. I did start them in peat pots and only the bottom of the pot came in contact with the water. When I planted all my root crops I would pull the affnan siphon and let the grow bed fill to the overflow. I would then dig down into the gravel until I felt or saw enough moisture to grow the root crop. I then planted slips, bulbs and put peat pots in. Then I would back fill accordingly. Carrots I dug a 2 foot sq area out till I had moist gravel and then I sprinkled in the seeds. I then backfilled with the gravel aprox 1 in over the top. The germination was excellent. Same for the radishes. I think I will skip the peat pots on the beets next time and plant directly into gravel. I did direct sow method and peat pot method for leeks and had better success with direct sow. The peat is just to wet. To be clear my water is about 1 to 2 inches below my gravel at the overflow point. Standard stuff there.

Kobus Jooste said:

Hello all root crop growers.  I would like to aske everyone if they have seen vastly different results based on the water flow patterns employed in their root crop beds?  I had flood and drain in the sand bed to start off with, and the beets were really not all that happy.  I started over, and added a surface distrubution grid over the unit, with a balancing valve on the outflow to ensure that the NFT does not overflow. The result is now that the bed only floods about half-way to the top at most, but the sand still gets a good wetting every hour.  The plant growth change has been immediately obvious.  I'm working on the assumption that a dry (relatively dry in any case) media with frequent surface trickling is much better than traditional flood and drain.

[Kobus Jooste]

Well then David, it looks like my approach is a bit different and worth keeping it going to see what the different flow patterns result in.  There could also be obvious sand / gravel differences in how the plants respond. I wet once an hour over the surface of the sandwith filtered water.  I will keep going like this - p.s. the potato is also in this bed getting the same treatment.

[David Waite]

Kobus definitely keep going. I am following your experiment and think you are on to something. I saw your potato and was excited. Mine didnt even germinate. It just rotted and became worm food.

Kobus Jooste said:

Well then David, it looks like my approach is a bit different and worth keeping it going to see what the different flow patterns result in.  There could also be obvious sand / gravel differences in how the plants respond. I wet once an hour over the surface of the sandwith filtered water.  I will keep going like this - p.s. the potato is also in this bed getting the same treatment.

[TCLynx]

I've seen some carrots rotting in my gravel beds lately.  I think this is probably more to do with the heat and perhaps pests because I have gotten carrots to grow fine in flood and drain gravel and even constant flood gravel in the past.

 

I have noticed that the taste of the carrots from my big system isn't as sweet as the ones grown in good compost.

 

Beets did well where the ants didn't do damage.

 

Most of my flood and drain gets flooded once an hour but I have a few that get flooded every ten minutes.

[Safwat Zaki]

Hi David,

Can you tell us if you are adding any other oganic fertilizers to grow rootcrops in your aquaponics system? The other question is what kind of food you are feeding your fish? I know potatoes don't like wet feet, my suggestion is to grow it in a different GB into dry medium such as perlite or compost overlaid cocconut coir using its wick action to water the plants.

Thank you for any information. Safwat

[TCLynx]

I know most root crops need potassium to grow well so if your system is short of potassium you may have trouble.  I know my big system has a problem not only with the Iron lock out due to high pH but.....

Also because of the overabundance of calcium (shells as 40% of media=too much calcium carbonate) in that system the potassium tends to precipitate out of solution and I see lots of potassium deficiency issues too.

 

Still searching for more plants that like the alkali water.  Watercress is great in winter here but the heat just decimates it so need more greedy plants for summer (other than bananas.)

 

Uh, I suppose you could sort of think of water chestnuts as root crops and they seem to be doing well for me in the wet alkali conditions but they don't seem quite as greedy as the cress.

[Safwat Zaki]

Hi Kabus

From my experience I found that most of plants don't need wet feet, just a continous light moisture around their roots so they can breath, the best approach in this case is using a wick system thru adding perlite on the top of cocconut coir or clay pebbles in the flood and drain unit

This way it is easier also to plant rootcrops than planting directly into the gravels.

Kobus Jooste said:

Hello all root crop growers.  I would like to aske everyone if they have seen vastly different results based on the water flow patterns employed in their root crop beds?  I had flood and drain in the sand bed to start off with, and the beets were really not all that happy.  I started over, and added a surface distrubution grid over the unit, with a balancing valve on the outflow to ensure that the NFT does not overflow. The result is now that the bed only floods about half-way to the top at most, but the sand still gets a good wetting every hour.  The plant growth change has been immediately obvious.  I'm working on the assumption that a dry (relatively dry in any case) media with frequent surface trickling is much better than traditional flood and drain.