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.

[TCLynx]

My systems.  Big system media is a mix of 1/2" brown river rock (mostly quartz type rocks that don't affect pH) and shells (I don't recommend the shells but I've still done OK since they only buffer up to 7.6 rather than above 8 the way most limestone will.)  I've grown carrots, beets, onions and turnips nicely and radish grows well too though we don't eat much of it.  I've also grown sweet potato and jicama in that system.  Make sure the get the jicama out before it gets cold and starts to rot, it needs a really long season though and can take over the world as tropical vines are want to do, the foliage and been pods of jicama are supposedly poisonous so you are only growing it for the roots that I've had get anywhere from baseball size up to basketball size.

 

The 300 gallon system has the brown river rock but no shells.  Turnips, onions, radish, beets, and carrots all did great.  I have not tried the sweet potatoes or jicama in that system at this time but see not reason that they wouldn't do fine.

 

I have not yet tried peanuts in aquaponics.  I don't know if the plants would be able to peg the flowers in gravel so this might be appropriate to a sand bed.  Perhaps I should try it this season though since I haven't planted any peanuts yet.

[David Waite]

Interesting TC on the jicama. When you get into aquaponics the endless rumors of cant grow root crops or tomatoes ect...ect is pure gibberish. What  I am finding out is quite the opposite. I think aquaponics is as unique as soil types in that some people might struggle with certain crops depending on system design or media ect.... I am curious to put to bed the rumor that you cant grow carrots for example. If people reply to this and the ones that are successful have a round media then this might help future growers. If we find out cracked gravel works fine as well then we know otherwise. I have found cracked gravel to be locking into itself in nature as we use it in walkways for that purpose vs round rock wont lock or compact. Hope the more experienced aquapons chip into this discussion as well...........Take care.

[Ricky Flickenger]

I hope they do, this is a great discussion! Next year I want to experiment with root crops and would love to see others findings!

[Robert Magnes]

I have been wondering about growing root crops. I think I will try some carrots, radishes and onions. My Roma tomatoes and Sweet Banana peppers are producing like crazy. I am just waiting for them to get ripe enough to pick. My wife even took a cutting off the tomatoes and planted it. It started growing and is now producing fruit. Our system is a media bed useing I guess standard cracked pea gravel from Lowes. It is flood and drain with a bell siphon cycling every 17 min. The tank is a 50 gal. hard pond liner with a small kiddie pool for a grow bed, it is around 45 to 50 gal. It has 5 Shubunkin Goldfish in it and has been up and running for 7 months.

[TCLynx]

It is important to note that some crops (roots or not) will only thrive when you plant them in the correct season.

 

I've found that here in FL many seasons are quite up-side down (don't plant broccoli in the spring here like you would up North.)  Many of my favorite root crops happen to be cool weather crops so will be best planted in the fall here but in a cooler temperate climate one might be able to grow those fall and spring.

 

I guess what I'm saying is don't automatically assume that a failed attempt is the fault of aquaponics.  Keep in mind season (day length for onions) temperatures and potassium are also very important to root crops. 

[Harold Sukhbir]

Hi All,

Do you all think that the average 20 min. cycle time is good for root crop? I've no experience here, never grew any(except tomatoes), and would like to learn.

[steve]

I understand potatoes do not like to produce many tubers when the root temperature over 80 degrees. Also I would purchase seed potatoes. Not the ones you eat in the store as they may contain sprout inhibitor, among other things. I would really like to grow them as sometimes they are over 1.50 a pound here. Maybe there is a more heat loving variety out there. Glad to hear you're other crops are doing well!

[TCLynx]

Sweet potatoes are heat loving and water loving at least until you get ready for harvest.  As to sprouting sweet potatoes, Buying slips generally means (I hope) that you are getting pest free stock, but if you can get the root from the store to sprout (suspend it with some toothpicks in a cup of water by the sink and change out the water regular.)  When it sprouts you can cut off pieces that have some roots and some vine/leaves and plant them.  To avoid chemicals and stuff you might buy organic sweet potatoes from the store (then you can eat one to see if you like the variety before trying to grow it.)  Two and three years ago I grew lots of sweet potatoes from slips I started off store bought stock but I did get a sweet potato weevil infestation the second year and so did not grow any last year.  We mail ordered slips this year.  Now is the time for planting Sweet potatoes.  By the way, the young leaves and vine tips are also edible.

 

Regular Potatoes like a long but cool season to grow and don't need as much water as sweet potatoes like, they are a challenge to grow here since it does get too hot but if we try to grow them through winter the freezes will knock them back too so a challenge.

[Kobus Jooste]

I think the end result will have a lot to do with the amount of "give in the media.  I have had carrots accidently seed in my gravel beds ( was plantin seeds in trays on top of the bed for soil planting) and although they germinated and tried to grow, they ended up looking like roadkill as the gravel did not budge (I had angular 19 mm quarry crush).  In 16 mm river stone, the radish I planted did well too, but the gravel still did not give way enough for the tuber/root development needed and I had more leaves than root.  I am not trying all of the typical root stuff in sand to see how that will go, as there will be no issue with space for expansion.  Never tried with hydroton but have seen many reports of root crops doing well in that. 

[David Waite]

Kobus interesting on the cracked gravel causing deformities. I am curious as more aquapons reply or give their stories that maybe cracked or angular rock gives root crops to much pressure to form a concentric shape of the root crop. Thanks for you imput.

[TCLynx]

I'm also going to note here that it might not be just simply the angular rock that may tend to lock together making the roots work harder to expand, but also the container the rock is in.  Because I have seen root crops push pretty darn hard against gravel to move it out of the way so they can grow.  Now if the container the gravel and crops are in, doesn't allow for the easy movement of gravel out/up and away, it has been known to happen that root crops can buldge out and even bust a plastic container.  SOOOOOO

Suggestion being that perhaps barrels cut the long way might be most appropriate to root crops.  See as the roots push against the gravel it can slide up and out fairly easily while if it is in a straight up sided container, it will tend more to just push out and buldge the container.  This is about the only time I'm going to suggest that a barrel cut the long way has it's place if you can see what I'm saying.

 

I've seen the results of potatoes grown in storage bin containers in hydroponics using perlite.  The potatoes tended to buldge the bins out and break them while the ones grown in a half barrel did fine without damanging the container.  Granted perlite is light weight easy to push media compared to gravel but I've experienced the buldge and bust option with a banana plant while the ones that were growing in the "barrel cut the long way" type beds didn't damage the beds, the gravel just tended to mound and rise up.

[David Waite]

This is good to know. So lets add a third dimension to this. If you are having success with root crops lets include the growbed design. Straight sides or angled. My sides are straight and the rock is round in nature.

TCLynx said:

I'm also going to note here that it might not be just simply the angular rock that may tend to lock together making the roots work harder to expand, but also the container the rock is in.  Because I have seen root crops push pretty darn hard against gravel to move it out of the way so they can grow.  Now if the container the gravel and crops are in, doesn't allow for the easy movement of gravel out/up and away, it has been known to happen that root crops can buldge out and even bust a plastic container.  SOOOOOO

Suggestion being that perhaps barrels cut the long way might be most appropriate to root crops.  See as the roots push against the gravel it can slide up and out fairly easily while if it is in a straight up sided container, it will tend more to just push out and buldge the container.  This is about the only time I'm going to suggest that a barrel cut the long way has it's place if you can see what I'm saying.

 

I've seen the results of potatoes grown in storage bin containers in hydroponics using perlite.  The potatoes tended to buldge the bins out and break them while the ones grown in a half barrel did fine without damanging the container.  Granted perlite is light weight easy to push media compared to gravel but I've experienced the buldge and bust option with a banana plant while the ones that were growing in the "barrel cut the long way" type beds didn't damage the beds, the gravel just tended to mound and rise up.