Topic: Hydroponics anyone?

[Leonie]

Good afternoon.

Well moving on from Grahams 'Extending tomato growing' thread.  I wondered if anyone else had tried growing with the hydroponic methods?

I am having pretty good results in this my first year but would love feedback from anyone else who may have tried it?  

Im looking at buying a lighting system and trying to grow veg all through winter in my greenhouse with a combination of electric and natural light.

Graham I hope you dont mind me getting the ball rolling  :)

[tim]

My only contact has been the site I mentioned. They do it all & are well recommended.

But before this goes much further, might it be sensible to have a heat, light, water, machinery , greenhouse, shed slot? None of those are edible plants.

[Leonie]

Yes you are right, sorry Tim/everyone  :'(

Im not quite sure what to do with the thread now, can someone move it?

[john_miller]

I have grown acres of plants hydroponically, so I may be able to answer some questions you may have.
The problem that any attempt to grow vegetables overwinter will encounter is the low light levels. I have been gently ribbed here in the past about bringing economics into my responses but I would assume that you are talking about growing tomatoes and cucumbers overwinter with the intent to be more cost effective than growing, for instance, cabbage?
These plants flower and fruit in response to climatic stimuli (a phenological response), the most important of which is light levels. Additionally these plants have an absolute minimum light requirement just to make vegetative growth. This is why lettuce is commonly grown overwinter as it's minimum light requirement to grow is lower than tomatoes or cucumbers, probably due to their provenance (lettuce is a autumn germinating/winter growing herb from the fertile triangle: tomatoes are summer growing perennials from northern South America, cucumbers are a summer growing annual, originally thought to be from the Middle East too). The phenological response is registered in the plant at the growing point so by illuminating this part you will certainly induce an earlier response than by generally illuminating the whole plant. In the depths of winter you would probably need one light per plant, held so close you could singe the foliage!
Long season tomato crops are normally started, under lights, in November, with the intent to get the first flowers in late winter and the first fruit ripening in mid spring. The crop will be carried through to late autumn. For a commercial grower 50% of the profit from these crops come before the end of May, when the price drops considerably. With this in mind I hope you will appreciate that if someone had been able to get earlier crops (and increase profits as a result) from tomatoes it would have been done long ago.

[tim]

What would we do without you, John!! = Tim

[john_miller]

There are as many responses to that, Tim, as there are people on this site! Some are probably not flattering!

[Jill]

Ignorant newbie (both allotment and forum) here so apologies in advance, but what's hydroponics?  Jill

[john_miller]

Literally, culture in water. In practice, growing a plant without what is commonly perceived as soil. This can include a continous flowing solution (Nutrient Film Technique), an interrupted one (flood benches) or using a physical substrate like peat, sand, perlite, rockwool to support the plant and liquid fertilising as often as needed.

[Jill]

Thanks, John.  What, then, are the perceived advantages of hydrophonics over soil-based methods?  Jill

[Hugh_Jones]

I grew tomatoes hydroponically for a couple of years in the early 1960s. The plants were grown in slightly inclined troughs containing washed black boiler ash (which in those days could be obtained in large quantities for the cost of cartage), and the nutrient solution I made up myself in accordance with the formulae contained in my then bible on the subject - Tomato Growing by Prescription, by Reuben Dorey BSc.

Although the plants (Perfection) grew well and produced plentifully, My family complained of the watery flavour (describing them as `shop` tomatoes) and I changed to the ring culture system, which was a lot less trouble and produced much finer tomatoes.

[john_miller]

What most people don't realise, Jill, is that the worst place you can try to grow plants is in the soil. It ties up nutrients, denying them to plants, and harbours pathogens, which will attack the plants at any opportunity. It often gets compacted, interfering with gaseous exchange with the atomsphere, and results in root death. It also warms up relatively slowly which can limit root growth; this in turn will reduce the growth of above ground plant parts. For plants in which the fruit is the edible part this will result in delayed fruit development and ripening. In greenhouses where lettuce is grown hydroponically two extra crops per year can be harvested.
Due to these factors tomatoes in greenhouses, well grown, may crop about 120t ha^-1 when grow in the soil. Hydroponic production, using peatbeds or rockwool, quickly produced yields of 250t ha^-1, following it's introduction.
If you search on this site for 'spuds'n'tyres' you will find a description of my brief association with Nutrient Film Technique (NFT). When it was introduced in the mid-1970's yields quickly rose to 300t ha^-1.  If you link to the Esoteric Hydroponics web site that someone else has posted elsewhere the drawbacks of the system are described, although, in my opinion, after four seasons using the system, they are a little overstated.
I spent the winter of 1979/80 in Israel managing a vegetable operation using the gravel of the Negev desert as a substrate to grow plants in. This, I think, would satisfy anyones definition of hydroponics. We dug in manure from the local kibbutz prior to planting (in a trench under the plants) but basically all the nutrition came from the liquid fertiliser we applied at every watering, the manure acting as a reservoir for the applied fertiliser probably.
While I do not doubt Hughs' findings with hydroponics, in independent blind taste tests conducted during the development of NFT consumers indicated a preference for tomatoes grown hydroponically, especially in NFT, compared to those tomatoes grown in soil. What we percieve as taste is a function of the amount of salts (not salt!) present in the plant tissue. As the amounts of these salts increase we find the food tastier. Plants grown hydroponically have much more access to these salts, as they are not competing with soil particles, nor with microfauna and -flora, resulting in higher levels of these salts in the tissue.
Hugh: the sixties are a little before my time. Whose idea was this? What is the cation exchange capacity of this substrate compared to, for instance, soil? I don't even want to think about the heavy metals present in this substrate!  

[tim]

Just been re-thinking my 'not-so-bright-idea' overnight.

If we take out the hardware, mechanics, services, pests & diseases from 'edible plants', what do we have left?? = Tim

[Leonie]

You were right Tim it probably could have been sited better elsewhere, however im one of those blinkered people and i've hardly noticed there are other sections to this site, as im having such a great time here!  I'd be happy for it to be moved to a more suitable area though  :)

I know you mentioned on the other thread that you use a light for your seedlings, may I ask is it a metal halide one?  I've been looking into the differences between MH and sodium ones, however the sites I've been directed to are usually where people are growing their 'crop' in cupboards with no natural sunlight at all, this wont be the case with mine.

On to the subject of growing toms and cucumbers because of the higher value of the crop as opposed to cabbage etc.  Well thats not really the case, its more that I enjoy growing food for my family and appreciate the home grown taste so would actually grow any crop, be it expensive in the shops or not.  I just want to have my own food year round.

Hugh, I have heard of people mentioning watery tasting veg and I wonder if it has something to do with making up the solution yourself?  I may be completely wrong but I know if the solution isnt spot on, or perhaps the ph is too low etc, then the plant may not be able to take up certain nutrients even though they are plentiful in the solution?  I use a ready made one and have found my toms to be more tasty than my brothers who is a tradional gardener.

John your articles make very interesting reading.  I havent tried the NFT methods myself, really i've used the wick method for everything, even seeds and its just so much easier.  Im not sure I agree with you on the lights being so close as to nearly singe the plants, I have only ever seen one hydroponic growers 'garden' and he wasnt growing veg, just big bushy houseplants, however he had and area about 12ft by 12ft with no natural light and he only had a couple of metal halides.  I do wonder if it would have been different for growing veg, but he did give me the idea to set up a MH in my greenhouse and see what would grow.

I have had great success in myfirst year using perlite/vermiculite as my medium.  The children have often pulled out a carrot, shook it and eaten it on the spot, no need for washing as theres no dirty soil!!

I've also changed over my aloe vera house plant to hydroponics and they seem to love it.  I dont have to worry about waterlogged roots due to overwatering anymore.

Thankyou people for your thoughts, I hope this thread continues as im on my learning curve and need the help!  :)

[graham]

Thanks for all the interesting and informative contributions to this thread.  As you will see from our previous discussions Leonie and myself have been trying out small amateur systems with some success and would like to take it a little further. For me the problem has always been the use of 'synthetic' fertilizers but since the introduction of organic based feeds I'm encouraged to try again - I stress this is a personal preference  I think Tim's point on the previous thread "extending the season' still makes a lot of sense, that we have to strike a balance between cost of production, volume of produce and quality although an amateur greenhouse is not exactly cost efficient anyway. One of the interesting fact of hydroponics is how they are used to deliver the vast majority of high value supermarket vegetables and flowers, I read recently that 90% of the dutch flower business is now under hydroponics, and yet people don't seem to know.  I'm not advocating trying to replicate supermarket type vegetables, that the last thing I want, but I do feel there is a place for hydroponics for the amateur grower

[tim]

Leonie - you checked the growthtechology site? Our thing is the 'Whitefire' light, & I use it as a day extension light - say 10 hours extra a day, whenever its power is better than daylight, except for a 5 hour night break. Its effect on lettuces was rewarding - really sturdy plants, which went straight out like this, & produced lettuce over a kilo each. = Tim

[Leonie]

Tim thankyou thats exactly the information I was looking for! Yes if I know that I can 'extend' my day by using lights then its definatley worth forking out money for a good light.  Were those lettuce grown to that size simply by using your light or were they in a greenhouse?

When i've read websites that explain how to use lights for growing (they are usually talking about 'pot' however, im struggling to find much on veggies) they say you need to use the white light (metal halide) for strong stocky healthy growth, however then you need to move to yellow light (sodium) to mimick the sun and encourage flowering. This is where my concerns lie, I simply wanted to use white light in my greenhouse and let the extra light and heat from the lamp grow my plants from seed to crop.  

I need to find some good sites that can simplify this white/yellow light thing.  

[tim]

In a cold lean-to. I germinated them in a propagator - despite the fact that lettuce are said not to like heat - & grew them on in daylight + 10 hrs extra with the lights. Sowed 22/5: germinated 24/5: put out 7/6: cut 25/7. = Tim

PS Don't faff around with sites - give Tim (yes!) @ growthtechnology a call & get a direct answer.

[Leonie]

Thanks for that Tim, I've used growthtechnologys nutrient solution before and been pleased with the results, bit pricey though.  I'll probably have a chat with them and discuss my lighting requirements.

Ozzy, why do you prefer soil?  And surely its messy if you are growing it in your cupboards.  Oh and yeah right you are going to give up some of your valuable growing space to lowly crops like toms and spuds!!  ;) ;D

[Hugh_Jones]

John, I doubt very much whether any enterprising horticulturist ever attempted to quantify the electro-positive element of black boiler ash, much less determine its exchange rate vis-a-vis soil.  It was simply regarded as a cheap inert aggregate and was also extensively used in the making of concrete `cinder` blocks for house interior walls and as a filling for house floors. As to heavy metals, in the early sixties these were things that only the mad scientists worried about in their esoteric discussions.  Don`t forget that in those days we happily poisoned our soil with DDT and its derivatives, dipped our brassicas in mercury (calomel) to ward off club root, fumigated our greenhouses with nicotine... need I go on?

The idea of using an aggregated medium was simply a `follow on` to the original idea of hydroponics after it was discovered that a plant growing entirely in nutrient solution would simply stop growing unless air was pumped regularly through the solution (I`m sure you don`t want a dissertation from me about the importance of the full development of root hairs).  An aggregated medium admitted aeration and consequently obviated the need for this, and black boiler ash was just one of several media used for this - others being gravel, sharp sand, or mixtures of these.  It was also used extensively among amateur gardeners as the base bed for ring culture for similar reasons, having the advantage over other media of its light weight when it all had to be shovelled out of the greenhouse, sterilised, and shovelled back in again.

Now there`s a bit of history for you!

As to fruit quality, I suspect (with hindsight) that Perfection was not the best variety anyway - I should have stuck with the Ailsa Craig and Stonor`s Exhibition that I grew when I was a mere stripling.

[john_miller]

Perhaps Hugh you are a potential goldmine, rather than simply a goldmine of information?
Accepting that work for some does indeed increase so as to fill the time available for it's completion, I imagine that a scientist at some point was able to fill a few spare hours by conducting tests on boiler ash and figure out how well it retained nutrients in comparison to soil. We just don't know where to look! I certainly agree that no horticulturist would have that amount of spare time though.
Another bit of history: when I was in college (1976-79) the horticultural department demolished their last two movable greenhouses as they were deemed irrelevant to 'modern' horticultural education. In truth they were, I have never seen any others, although you may have memories, or seen, them?
Someone I met recently has just become a manager of a farm that is changing from an uncertified organic (organic by neglect rather than intent) dairy farm to a certified organic vegetable facility. With the intent of boosting gross receipts and, subsequently, profit, the first structural changes being made on the farm are the erection of moveable greenhouses. This gentleman, thinking he was on the cutting edge of greenhouse production, was visibly deflated when I told him that he was simply re-inventing the wheel. The more things change the more they stay the same. I don't think we will get mercury or DDT back though!