London (change)
Today 14°C / 8°C
Tomorrow 19°C / 10°C
19 messages
19/12/2013 at 10:36

Like everyone here I always read all the gardening sections of newspapers, online and wherever we find them.

I quite often read the same 'solutions' that are often wrong or badly explained. Can you add that you have found or are just silly?

I will start with 'cluster your pots together during a frost for protection'

Plants do not release heat, so those pots all need to be in sun for a few hours to store any heat to provide any protection. Clustering pots anywhere where the pots themselves are not in sun is wasting your time.

19/12/2013 at 10:40

If the pots are clustered it makes it easier to throw some protection over them.  Perhaps they just needed to add that to make sense of the tip!

19/12/2013 at 11:11

You're right, though, the advice does rather suggest that the plants can huddle together like sheep or penguins to conserve their body-heat.

I suppose there would be some protection from the cooling effect of frosty winds. But as remarked already, the main benefit would be that youcould then protect the whole cluster with a layer of bubble-wrap or something.

KEF
19/12/2013 at 11:23

Ventilate GH's on mild Winter days. I think 15C is mild.

I know what they mean but mild & Winter don't go together for me.   

19/12/2013 at 11:31

I can't understand when you read 'Bracts' and 'Leaves' in the same sentence. I thought they were one in the same?

19/12/2013 at 11:41

They're different.  A bract is a leaf like structure found just below a flower.  Usually the flower is insignificant in form and size but essential for reproduction so the bract is brightly coloured to advertise it.  

Leaves are for transpiration and photosynthesis.

19/12/2013 at 11:59

Thanks obelixx,

That makes sense, I understand now.

19/12/2013 at 12:56

KEF - It's winter yet it's 8C at head height on our north facing back wall.   That is positively balmy.

19/12/2013 at 13:39

I find the labels with only hieroglyphs very unhelpful. Written for and international market but a lazy option nonetheless.

19/12/2013 at 16:25

"Hardy"

Bet it isn't up here, pal!!

I'm very pleased that the RHS have introduced a new hardiness guide - will the plant labelling companies use it??   3 guesses - 1 will do!

19/12/2013 at 16:38

In technical terms, the soil in the pots will radiate heat as infra-red radiation (heat) in all directions.  If a pot is surrounded by other pots, some of this heat will be absorbed by the other pots instead of being lost to the environment.  The effect of this is that (say) 10 pots clustered together will cool down more slowly than 10 pots spaced widely apart, so it is worth doing.

19/12/2013 at 17:39

I think I see what you're saying, Bob - do you mean that the soil heats up during the day and then stays warm, like a storage radiator? In which case yes, I suppose there may be some benefit from clustering pots when there are significant fluctuations in temperature between day and night.The soil can radiate heat if the sun has provided it during the day (although not if it's constantly cold).

But I'd imagine that to make the most of this effect, you'd need to un-cluster the pots when the sun is shining, to allow the pots' surfaces to absorb the sun's warmth and heat up the soil. If they do get really cold, they'll take longer to thaw out if they're clustered together, won't they?

19/12/2013 at 17:55

Highland Jeannie wrote (see)

"Hardy"

Bet it isn't up here, pal!!

I'm very pleased that the RHS have introduced a new hardiness guide - will the plant labelling companies use it??   3 guesses - 1 will do!

I have certainly seen online plants being described as hardy in mild parts of the UK...when you look into it (not on the site selling them) then sheltered, frost free and winter dry is the only way to keep them alive. That rules out everywhere (and yes I know parts of Ireland and the Scillies are very mild but they are also very wet and windy).

 

19/12/2013 at 17:56

Another common thing I see are online suppliers not giving the plant/pot size supplied. They have pictures of a flowering mature plant in the height of summer. So when people get bare roots or a 9cm pot with a twig in it they feel robbed.

19/12/2013 at 18:08

I ordered some wallflowers online, said they came in a 2litre pot. Which indeed they did, plugs pushed into a pot of compost! From a very well known female TV gardener! Another con.

19/12/2013 at 18:45
Sue Gough wrote (see)

I ordered some wallflowers online, said they came in a 2litre pot. Which indeed they did, plugs pushed into a pot of compost! From a very well known female TV gardener! Another con.

I had something similar. The plant was in a 1 litre pot and the roots where 9cm pot. It had fallen out and broke in transit because of it...

19/12/2013 at 18:59
Sue Gough wrote (see)

I ordered some wallflowers online, said they came in a 2litre pot. Which indeed they did, plugs pushed into a pot of compost! From a very well known female TV gardener! Another con.

 

blairs wrote (see)
Sue Gough wrote (see)

I ordered some wallflowers online, said they came in a 2litre pot. Which indeed they did, plugs pushed into a pot of compost! From a very well known female TV gardener! Another con.

I had something similar. The plant was in a 1 litre pot and the roots where 9cm pot. It had fallen out and broke in transit because of it...

Most annoying!  Hope you've both added these suppliers to this thread!:

http://www.gardenersworld.com/forum/talkback/name-n-shame/165744.html

 

22/12/2013 at 23:14

I like to see what i am buying, go to the garden centre shop local.

 i don't own a GH to raise plug plants in.

some plants are started in tiny plastic cages, or net, which can restrict the plants growth. especialy if let dryout.

 

22/12/2013 at 23:42
BobTheGardener wrote (see)

 

In technical terms, the soil in the pots will radiate heat as infra-red radiation (heat) in all directions.  If a pot is surrounded by other pots, some of this heat will be absorbed by the other pots instead of being lost to the environment.  The effect of this is that (say) 10 pots clustered together will cool down more slowly than 10 pots spaced widely apart, so it is worth doing.

Heat has to come from somewhere though and the soil is not producing heat by itself. If the pots are in shade then there is no heat to radiate.

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