Back to Business

I am finally back in Oregon after three weeks of intensive turfgrass education, and I must say I am very happy to be home.  I was super excited to see my wife and our two dogs, and to see how my hydro-garden was looking.  I had set up automation (irrigation and lights) on everything except for my wick watering bins, so I was fairly certain that everything would at least stay alive.  None of the units received any additional water, fluid changes, or any other care at all.  When I got back home at 3:00 am, I said hello to my dogs, and pulled back the curtain on my hydro-garden to see how things were doing.  I must say I was very happy to see how much everything grew while I was gone.  The most striking thing to see was the fennel.  They were hovering around six inches when I left, and by the time I got back, they had grown up into my light fixtures that I had raised to ten inches above the plants.  My lettuce bin was also packed with growth, and two of my cilantro plants had grown pretty large.

Healthy Cilantro, Sickly Basil, and Healthy Fennel

Luscious Lettuce and Kale

Gleaming White Roots = Healthy Plants!

Buttercrunch Lettuce, Ready to Eat

The only plants that appeared to suffer a bit from neglect were the radishes in the wick-watered units.  They were watered only once before I left, and there was nearly no moisture in the bins by the time I got back.  The leaves on about half of the plants were slightly wilted, and some appeared chlorotic (unable to produce chlorophyl, usually appearing yellow).  Yesterday, I filled the bins with a fresh 450 ppm nutrient solution, and I fully expect the plants to recover.

   

Radishes are dry, but still alive

Yesterday, after getting half a night's sleep, I went to work for a few hours, and came home to tend to my garden.  I pulled all the rafts from the bins, placed them between folding chairs, and started tending to the bins.  I checked the ppm of the remaining nutrient solutions in order to see how much actual nutrient was absorbed by the plants over three weeks.  The lettuce had consumed the most water and nutrients by far.  There were only about 1.5 gallons remaining out of the 4 gallons that were added prior to my trip, and the solution only read about 150 ppm, very low compared to the original 600 ppm .  The other bins were both at about 400 ppm after originally being mixed to 700 ppm.  I cleaned all the algae out of the bins and filled them each with 4 gallons of water, and mixed the solutions to 450-650 ppm.  I also changed out the solution from the reservoir that feeds the seedling tray and the coco bin.  This reservoir barely had enough water to allow the pump to remain submerged, and it was a bit dirty from the coco draining back into the reservoir.  I mixed this reservoir to 400 ppm.

Carrots and Radish in coco, sowed 3 weeks ago 

Seedling tray, mostly planted 3 weeks ago

Once everything had fresh water, I did a bit of rearranging so that the smaller plants would not be shaded by the larger ones.  I only have 3 rafts, so i placed the smaller plants in a true DWC lid that keeps the net pots suspended above the solution; only the dangling roots contact the solution.  I already had a fourth light fixture and a larger bin, so I set it up as a DWC using a lettuce raft to hold the plants deeper into the bin, but not actually floating on the water.  So, now I have 4 functioning DWC units, 2 of which are true lettuce rafts.  There are quite a few seedlings that are ready to move to a new hydro home, and I am currently working on a vertical drip system which will be unveiled soon, so stay tuned.  So, here is how we are looking now.

 DWC with thyme, lettuce, basil, oregano, zinnia and mimulus  

(trying my hand at some flowers) 

Lettuce raft bursting at the seams

Cilantro and fennel (after pruning)

New plantings: snap peas, spinach in coco, basil, and zinnia

The whole shebang

Garden Happy!

Far from Home

     For the last week I have been in New Brunswick New Jersey, attending the Rutgers turf grass management course, so I am improving my plant knowledge, but I am away from my plants at home.  Before I left, however, I did implement measures to increase my plants' chances of survival.  The DWC units should be fine because the roots are constantly submerged in nutrient solution, but I increased the volume of water in the tanks by a gallon, so there should be very little chance that all the water will be lost due to evaporation or transpiration.  I also mixed the solution about 50 ppm stronger than the previous batch of solution so that the plants will have plenty of food while I'm gone.  I also raised the lights a few inches to make sure that the plants won't touch the bulbs if they get too tall.
    
     As for the germination tray, I bought some materials and set up an irrigation system.  I also set up an additional bin for root vegetables, which I seeded the day before I left.  The germination tray is now a flood and drain system.  In my flood and drain system, the tray is set up on an angle with a 1/4" drain on the down hill side that runs back into the reservoir on the floor.  The theory is that nutrient solution is pumped into the tray faster than the drain can get rid of it.  This action floods the tray to a shallow depth, wetting the rockwool cubes and coco net pots I have in the tray.  Once the pump stops, the solution drains back into the reservoir and allows air to be absorbed by the plant roots.  I set the timer to irrigate 3 times daily for 15 minutes each time, and this seems to be adequate.

Notice the debris on he bottom of the tray.  

This is coconut fiber that has washed out of the coco pots.

     I also set up a drip irrigation system on the new root veggie bin that is filled with coconut fiber.  This system is simply tied in to the same nutrient reservoir as the germination tray.  I installed a 1/4" drain in one corner of the bin, and this drains back into the nutrient reservoir.  I used coconut fiber because it is a neutral medium, has decent water holding capacity, has a texture similar to high organic matter soil, and has a high cation exchange capacity.  

     CEC is not necessarily something to be concerned about in hydroponics, but in this case, it may be relevant.  CEC is a soil's ability to hold onto positively charged ions of various nutrients such as ammonium.  In hydroponics, nutrients are dissolved in water and are constantly being delivered directly to the roots, so no soil is needed for positively charged cations to bind to for slow nutrient release; the nutrients are always available to the plants.  In soil, a decent percentage (up to 50%) of nutrients are lost and made unavailable to plants due to leaching past the root zone, biological breakdown by microbes, and various other factors; this makes CEC in soil critical for successful plant growth because it allows unused nutrients to bind to soil particles for constant feeding.  Organic matter and clay particles are the only elements of soil that actually have CEC because clay and OM have negative charges.  

     My hope is that with the light irrigation schedule in the coco bin, the coco will basically become super rich soil with plenty of cation binding sites; hopefully a good growing environment for the root vegetables.

     With the addition of this extra level of automation, my germination tray should be more productive even when I'm not out of town because I will not have to water seedlings manually and sporadically.  So, here are some pics of my plants the day before I left: 1/7/12.

 Cilantro and Thyme

 Lettuce and Kale

 Cilantro, lettuce, basil, and fennel

 Carrot

 Radish

 Herbs

 Herbs

 Lettuce and Kale

 Lettuce and Kale

Herbs