Troughs

[penstemon]

And ...
shale trough with...I was going to say what's in here but I'm feeling too superstitious.

[Lesley Cox]

Just catching up with this thread after months away from it. Where was it? Didn't appear in my Inbox. No matter, it's here now.

A question: Who WAS Walter Shrimpton?

[Lvandelft]

A question: Who WAS Walter Shrimpton?

Calceolaria Walter Shrimpton was the result of a cross of Patagonian C. darwinii  with C. fothergillii from the Falklands. The cross was made by Michael Shrimpton,  (still?) an alpine plant specialist from Essex, who named the plant after his father.

[Gerry Webster]

As a newbie, recently bought my first trough. It is empty and so have been reading about composts etc. Have read about the problems of a perched water table and why not to put crocks etc at the bottom of the trough. It all makes sense. However, is it not the case that most people put their troughs on blocks and that will create a perched water table?

Confused.

All my hypertufa troughs,  except one,  are raised on blocks & contain rubble (crocks) + sharp sand in the base.  The exception has no base - it was cast directly on the soil - but otherwise has the identical rubble + sand. I use them to grow bulbs & in more than 25 years I have never had any obvious problems with drainage.

[astragalus]

All of the troughs here are sitting on cinder blocks, and have for about a quarter century. Most require daily watering during the summer.  I took these pictures a few minutes ago.
1. trough with porophyllum saxifrage (my favorite plants) trying to escape, and Primula Linda Pope, among others. Trough was broken and I glued it back together

Bob, when you say you "glued it back together", what did you use?  I haven't had any long-lasting luck trying this with broken troughs.   With an older trough you usually have very established plants you don't want to attempt moving.  Gluing back is a
worthwhile alternative.

[rgc]

Been reading the answers to the perched water table issue with interest. I can see the definite advantages of avoiding a perched water table with bulbs in pots. However, troughs have a much greater volume (and depth) and most growers have success with putting their troughs on blocks with crocks and other drainage material in the base. The use of a wick is interesting, but does not seem to be widely used. The conclusion would appear to be that as long as you have a well drained compost with grit and sand, both approaches will give similar results. Or am I missing something?

[Paul Cumbleton]

Hi Bob,
The problem with putting crocks or other drainage material at the bottom of any container is that it does not actually help the container to drain - in fact quite the opposite, it actually hinders drainage by, amongst other things, raising the perched water table. You can read a detailed explanation of this effect here: http://www.pacificbulbsociety.org/pbslist/2007-February/v42msft361un0q238ci4t8eiv6.html

That being said, these effects are relatively small and many plants can actually cope with them. This is why I agree with you that in a deep trough growers often have success even if they have put unnecessary materials at the bottom. However, if you were trying to grow species that are particularly sensitive to moisture levels then success would be more likely if the whole container were filled with a well-draining mix without anything else added in layers beneath.

Paul

[rgc]

Thanks Paul.
I had read your interesting article and you certainly make a very convincing case for plunging pots in sand.

As you say, the effects are relatively small, especially for troughs.

I gather that the main reason usually given for crocks is a fear that the drainage holes will get blocked.

[Gerry Webster]

In my experience if the gaps between the crocks/rubble in the base of a container (trough or very large pot) is filled with sharp sand then the mix above drains perfectly well - at least as well as if the container was filled with the the mix alone. I see no difference in principle between this procedure & standing a pot on sharp sand to facilitate drainage.

[astragalus]

Paul, I think the problem is that many troughs, at least those available in the U.S., are NOT deep enough.  My best trough came from Elmdene (spelling?) and it is 18" deep.  Everything performs beautifully in this trough.  Most of the others are 6 to10" in depth and I live in a very windy, cold area with winter minimums to -20F (but not in the last few years).  It is brutal for troughs and their plantings.  Some of them are protected from winter wet with a rain shield which is open on the ends for good air circulation.  Personally, I've found the deeper the trough the better it is for the plants.

[Tim Ingram]

Anne - Paul showed us the value of deep containers beautifully by simply using a rectangular wet sponge and holding in a sideways and vertical position. In the former it held water at least halfway up and in the latter the water drained away much more leaving only the bottom part of the sponge wet. I suppose the best way to use shallow troughs is to build up the planting with rocks and crevices so you actually increase the depth considerably. One of the best 'troughs' I have seen was made using upright paving slabs (2ft x 2ft) in Mike Smith's nursery, as was, near Swaffham in Norfolk. A shallow trough I have looks quite nice but the moisture levels fluctuate far too much. But there must be many exceptions that prove the rule!

[astragalus]

Tim - I've seen that sponge trick demonstrated and it certainly shows the value of depth in troughs.  But even more it is the necessity for root space, especially for tap-rooted plants of the Fabaceae.  With a very shallow trough you need to be very clever with watering and also fertilizing because whatever nutrients are there will be quickly exhausted.

[rgc]

Does anyone have any experience or comments on the use of (non clumping) cat litter as part of the compost for a trough? I take it that the point is that it will absorb water from watered compost and act as a reservoir, making water available if the compost gets too dry. So it will cut down on variations in moisture levels while also acting in a similar way to grit. (Like perlite?)

Last year we got a new cat from the cat shelter (elderly, arthritic and high blood pressure) and so she was kept in initially. She now asks to go out and so we have left over cat litter. Put some of the litter in water outside about 6 weeks ago to make sure it would keep its structure and it has not been affected in any way.

[Lesley Cox]

Thank you Luit, for the note about Walter Shrimpton. So many people are commemorated as named plants but we (I) frequently don't have a clue who those people are or were. This plant is truly wonderful (it must be, I've lost it several times ) and it's good to know the background.

[Lvandelft]

Thank you Luit, for the note about Walter Shrimpton. So many people are commemorated as named plants but we (I) frequently don't have a clue who those people are or were. This plant is truly wonderful (it must be, I've lost it several times ) and it's good to know the background.

Lesley, while researching on the net as well, I found an interesting article which I totally forgot to add to my reply:
http://www.essexchronicle.co.uk/brings-best-horticulture/story-19605226-detail/story.html
When clicking on the > in the picture you'll see a pic of Michael Shrimpton.