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"Forced" Vegetables · Hydroponics Daily

• 0:00
  Hi there, welcome back to Hydroponics Daily with me, Dr. Russell Sharp.
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  Now come with me on a journey to a dark, distant place, lit only by candlelight.
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  Can you hear those plants growing in the dark?
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  Yes, we're in the Rhubarb Triangle. What the hell is the Rhubarb Triangle?
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  Well, it's the place where 90% of all forced rhubarb is grown,
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  and it's in Yorkshire in northern England.
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  Forced rhubarb is rhubarb that is grown in the dark to produce succulent sweet stems.
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  Today's subject of Hydroponics Daily is forced vegetables. These are all vegetables
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  that are grown normally in their first year and then in their second year,
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  before they sprout and regrow, they're taken into the dark and they etiolate.
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  This means that they turn white or whitish so
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  the term forcing is not great because it
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  also means to force a plant into flowering so forcing
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  is not great the other word for this technique is also called blanching and
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  blanching is not great either because blanching also
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  has a culinary meaning and meaning you know to soften
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  tissues by boiling them so neither of
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  them are great etiolation is the technical scientific term and there are certain
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  crops where this is used so we've talked about rhubarb and it's grown normally
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  in a field and then they're called corms they're dug up and then they're all
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  jammed into a warehouse and given treatment to make them.
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  Detect a winter period or a cold vernalization period
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  then warmed up everything's dark i think they use either
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  green leds or candle candlelight they used to
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  use candlelight until very recently anyway green
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  leds are good because they the plants don't detect them the phytochrome
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  doesn't detect them and then you they produce
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  these pinkish to white stems which are
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  much more succulents and sweeter than normal rhubarb normal
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  rhubarb's great got it there in my garden but as
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  soon as you've eaten it you can feel your teeth getting soft
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  because of the high oxalic acid
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  content in the in the petioles and so
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  you don't want to be eating too much rhubarb it doesn't taste as good as the
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  forced rhubarb that is the creme de la creme that's the stuff that goes to the
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  high-end restaurants the forced rhubarb interestingly if you eat the leaves
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  of rhubarb extremely potent well inducer of diarrhoea, shall we say.
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  And if you eat wild rhubarb, you can actually poo yourself to death.
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  You can actually, you know, it's that bad. It's that bad a laxative.
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  That's the word I was looking for.
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  So wild rhubarb leaves stay way clear.
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  PTOs, they're fine with a bit of sugar. They're lovely, but they do make your
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  teeth soft because of the oxalic acid content.
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  And if you eat too much oxalic acid, you can get kidney stones, I believe.
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  But I'm not an expert in human biology, so I don't know
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  so rhubarb nobody's growing hydroponic rhubarb
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  it's just too big a plant i think to be grown hydroponically
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  the size of the hydroponic unit you would need would be just too massive even
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  though hydroponics is is very popular in wakefield and around there in the rhubarb
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  triangle i think it's about 25 square meters no idea what that is in square
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  miles the next crop that's grown.
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  In a forced way is asparagus so
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  again it's a perennial plant and then they they
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  cover it or dig it up and dig the corms
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  up and then force them to produce those white sprouted
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  asparagus which could sell for a lot more
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  than the normal green stalked asparagus you can
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  as well as putting like commercially the rhubarb goes
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  into a warehouse you can get these bell terracotta
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  jars to stick over the rhubarb corms in
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  in the spring and then to blanch them
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  and the same for asparagus however those terracotta
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  bell jars are ridiculously expensive
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  so you're better off just getting a plant really big plant pot maybe a big rose
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  pot and then covering the the drainage holes up with some plastic that can't
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  be see-through because nobody's paying 200 pounds for a bit of forced rhubarb
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  you know for the sake of those bell jars so asparagus is another one,
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  So asparagus, blanched asparagus is very expensive, not as expensive as hop asparagus.
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  Hops in the cannabis family, the most expensive vegetable in the world is hop asparagus.
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  And that's where you, as soon as the hop dies down,
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  it's what we call a herbaceous perennial in that it dies down into the root
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  system in the winter and then shoots up in the spring and then produces a vine
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  where those female buds, those female flowers, is what you harvest.
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  However if you get them before they turn into a vine and get the sprouts they
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  look like asparagus they're called hop asparagus and a very small amount of
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  that can sell for 10 pounds to a restaurant and god knows how much they charge
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  in michelin style restaurants for hop asparagus and the reason it's so expensive
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  is because you only get a certain amount per hop field and then that.
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  Really cuts back and severely impacts the ability
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  for that hop plant to then produce hops that can
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  be used for beer so you you are you are sacrificing hops
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  to make hop asparagus so jim one
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  of our customers who grows hops he has tried it he has sold a bit but
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  it's not a big thing it's not a big crop if you think hop you
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  could grow hop asparagus hydroponically you know
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  there are people growing hops as but commercially then
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  hop asparagus would be good big good one to try anyway i've
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  digressed away from forced vegetables i was talking about forced
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  asparagus i've done rhubarb now the
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  real one that is also grown hydroponically is endive which is chicory isn't
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  it and we think of chicory as the root i've given up coffee this week last week
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  and this week and one of the alternatives is chicory and trickery drink i'd
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  rather just drink hot water than drink trickery to be honest though,
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  Adra or you know, Rubosh chicory sounds disgusting, it's a coffee substitute, very popular in Europe,
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  in sort of you know recent history, however they found that if you didn't harvest
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  the chicory roots then you could actually.
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  You could the next year, if you kept them in storage, the roots,
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  they would sprout and it was delicious sprouts, and then you know the white
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  sort of rugby ball shaped.
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  Vegetable that's how it was discovered it was it
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  was sprouted in warehouses where they store in the chicory roots
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  so now it's a commercial and and there it's
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  not north yorkshire where that one's grown it's belgium it's
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  a belgium endive it is is where
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  and belgium's where it's grown and it's called
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  white leaf there or witloof and they
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  now also grow it hydroponically in its second year and
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  there it's called hydro witloof i'm told
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  so and that hydroponic method was developed in the
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  1970s so probably one of the very first hydroponic crops
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  so we must look at chicory and think oh it must be related to lettuce looks
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  a bit like lettuce it looks like a sort of like an iceberg lettuce or or even
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  a chinese cabbage looks a lot like a chinese cabbage but no it's not it's it's
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  chicory it's a perennial and it's in the chicory's in the daisy family let's have a look,
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  what family is it in yep the well the aster family yeah daisy family it's a
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  really big plant family there there are like 32,000 species so and then Chinese
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  cabbages they look like they're.
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  Etiolated but they're not really they just grow that way with not much chlorophyll
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  in the lower leaves so they look that's why they look a bit like Belgium endive
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  but they're they're not related,
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  completely unrelated actually you know and more
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  more endive is more closely related to lettuce but
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  even then it's a it's a long shot because lettuce is not
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  a perennial and so yeah that's
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  they're the main forced vegetables if i've
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  missed any forced vegetables then please let me know i'm more than happy to
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  do an updated episode and that's been it for hydroponics daily for today make
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  sure you click follow so that you always get to hear this absolute rambling
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  nonsense every single day on your phone thank you very much for listening goodbye.