Latest / Hydroponics Daily / Why Is My Rhododendron Flowering in Autumn? The Truth About Precocious Blooming

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Why Is My Rhododendron Flowering in Autumn? The Truth About Precocious Blooming · Hydroponics Daily

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  Hello there and welcome back to
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  Hydroponics Daily, your go-to podcast for everything soilless cultivation.
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  I'm your host, Dr. Russell Sharp, the founder of Utrema Ltd,
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  and we manufacture interesting fertilisers, novel biostimulants and organic biopesticides.
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  Today I have a question that came in from my GP, my doctor, and she said,
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  why is my rhododendron flowering this autumn?
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  So rhododendrons normally flower in the spring and produce very vivid displays,
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  ornamental displays, but sometimes they flower in the autumn.
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  And I have grown thousands and thousands of rhododendron plants as part of my
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  PhD studies back from 2000 to 2004, so I am well-placed to answer this question.
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  It's not just rhododendrons that do this.
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  A number of crops and plants, ornamental plants do this.
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  I was walking around Charlie Coat Manor today,
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  which is a National Trust manor house here in Warwickshire near Stratford-upon-Avon
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  where William Shakespeare was born and I saw some snowdrops appear and that
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  is precocious flowering.
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  They should not be around at this time of year and that's because
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  normally they they have the environmental
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  signals they've picked up are i've sort
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  of tricked them into flowering at the wrong time so normally it's a a warm autumn
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  causes this and you think great i've got double flowering i've got flowering
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  in the autumn and flowering in the spring this is great two displays however
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  this is not the same as a second set of flowering what we.
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  Secondary bloom it's precocious flowering this means that
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  these flowers will not you'll not get
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  flowers on those stems in in
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  in the spring and so you've actually dampened and
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  weakened your your massive floral display by having precocious flowering and
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  also they were if it's a a fruiting crop then you won't get fruit on them they
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  will die and wither with the winter conditions and the frosts so not to be confused
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  it's something you normally do not want is precocious flowering.
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  And what else can we say about it so it's yeah it's grown but it's
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  caused by a stress of some
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  sort now what's this got to do with hydroponics well it
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  could potentially be an issue in hydroponics if you think about strawberries
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  normally in strawberries they grow day neutral strawberries if you're trying
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  to get them to be grown from seed to harvest in the hydroponic setup so if you're
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  continually growing in hydroponics then you would just use day neutral ones that don't,
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  respond to photo period but also they don't respond
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  to a winter chill they will just flower and fruit regardless however these
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  are considered not as good as the june bearing
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  short day varieties and these
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  are the ones that are grown for wimbledon which is in june and
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  they're grown in hydroponically in in
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  cocoa with in gullies with hydroponic feeds there
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  is a a topic for hydroponics and
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  if these flower in the autumn then that is obviously a loss of strawberry crop
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  so that's a big issue so if you're growing june bearer strawberries then outdoors
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  even if it's hydroponics then then that could be an issue you're growing them
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  indoors then obviously you're probably not going to be growing dune bearers
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  but you might be growing them hydroponically indoors,
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  for propagation purposes so you might be getting them from seed or from from
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  a plantlet cut off the main mother plant,
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  growing them indoors, getting them booked up, and then they may flower too early,
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  so they might initiate the flowers.
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  And that's an issue, and you can run into issues when you're growing perennial
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  plants in vertical farms or in grow rooms indoors with artificial conditions and artificial lights,
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  because there are a whole host of different problems you can get.
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  So if you try to grow, I've got a Venus flytrap, and after Halloween, which was yesterday,
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  I have to take get out of my grow room and let it die off
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  and let it die down because it just won't be survived if you keep it growing
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  too long and because it needs that winter dormancy so don't think just because
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  you can grow you think oh i'll give it the perfect conditions and it won't go
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  dormant sometimes the plants need it for proper development if you try to grow an apple tree.
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  Indoors without any cold treatment it won't produce any apples it'll just keep
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  on growing vegetatively because it needs that cold to initiate flowering and for bud burst.
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  It just won't burst its buds and it won't flower properly and the flowers probably die off.
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  So there are certain plants that can't just be grown continuously indoors.
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  They need to receive a cold treatment.
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  I know you could put that cold treatment into a grow room. You could have a cold store.
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  When I was doing my PhD, there were cold stores for
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  apples and rhododendrons and things like this so that you could make them
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  flower at certain times of the year and that's what you do if you're
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  growing for the chelsea flower show which is the most prestigious horticultural show
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  here in the uk they force them into the cold the ornamental plants and then
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  bring them out early from the cold store to get them to flower it's the right
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  time for the chelsea flower show which may be months away from when that plant
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  would normally flower so you this is not the case with say.
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  Tomatoes and cucumbers or even legal cannabis where you don't have to worry
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  about a cold treatment because they would never experience that in their.
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  In their natural environment because either they are
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  tropical perennials or they're annuals so
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  for perennial crops if they're
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  woody or not then you need to consider do they
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  need a cold treatment and do you need to protect them
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  from precocious flowering before
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  before that cold treatment so as i
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  say this would be a big issue for say hydroponic strawberry
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  growers who've grown outdoors or in greenhouses especially in
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  greenhouses because they're getting a warm winter warm autumn whereas
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  they would normally get a much colder one so you might need a
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  special variety that's much tolerant to precocious flowering
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  just like you have lettuce plants that are tolerant to
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  bolting any flowering on say lettuce or
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  spinach cabbages is precocious flowering and
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  that's deleterious because it ruins the crop basil things
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  like this and you just want don't want them flowering anytime it's not
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  a case of early flowering so something to consider it's something
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  that will become more of an issue as vertical farming
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  and indoor growing away from greenhouses and polytunnels try
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  to get away from leafy greens and microgreens and just
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  vegetative growth and trying to
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  diversify away from annual crops like tomatoes cucumbers
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  legal cannabis and cut flowers if you try to grow something more complex that
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  requires a winter period then this is going to become a real issue and this
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  is one of the reasons that everyone's looking at hydroponic strawberries at.
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  The moment because it's a big crop but it's difficult to grow and no one can
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  crack it or very few people have managed to crack it.
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  There are loads of crops like that though that you would need a winter period
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  for flowering so like raspberries.
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  Plums, apples, all sorts of crops that aren't grown commercially,
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  hydroponically, and having a winter period and making sure they flower at the
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  right time and that you can introduce pollinators and fruit set is going to
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  be a massive issue and needs to be considered.
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  So if you've looked at this in an indoor growing environment and had issues
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  or found potential solutions, then let me know.
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  I heard a good podcast today and they said that indoor growing is growing indoors
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  in in a grow room is you're playing god and when you're in a greenhouse or a
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  polytronal then you're playing with god and i thought that was a good analogy
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  so yeah that's a good one i'll end on that.
• 7:56
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