Wisley Alpine Log Feedback

[Gene Mirro]

What medium are they using to plunge the pots in?  It looks like sand/gravel.  Do they do anything special to keep the potted plants from rooting into the plunge mix?

[Paul Cumbleton]

Thanks for the comments & questions everyone, here are some quick answers: Yes Maggi, the Aluminium frame of the new house should be pretty much maintenance-free. Alitex did leave us a couple of tins of green touch-up paint in case of the inevitable occasional knock or scratch. This coming week the electricians will be sorting out the power supply and our on-site chap re-connecting the water supply. Once these are done we can at last get on to the exciting bit – moving in the plants and putting on a new display!

Gene, the plunge medium is washed sharp sand. As this house is just for display, plants are not in it long enough to root out into the plunge. However, when back behind the scenes in their growing houses most are also kept in plunges and here it can be a problem. We don’t have a real solution other than to lift pots occasionally and trim off protruding roots – most of them don’t seem to suffer from this indignity. The many benefits of plunging far outweigh this down side.

On to the meadow questions. Let people loose with scythes…? I have visions of multiple unattached feet…and worse still think of the paperwork to do a sensible risk assessment!! More seriously, moving the cut grass to the arboretum is done the same day, without composting. The trees are grown in grass but there is a 2 metre diameter circle around each tree where there is no grass (i.e. it is bare ground). This is because research has shown that trees, especially young ones, establish and grow better by not having grass or other competing plants around their bases. The grass is put onto these bare circles where it helps to keep the weeds down. We have considered other options; the best solution would probably be to get the hay baled and fed to horses in local stables. However the amount we produce is so small that this is uneconomical and we think the best compromise solution was to use it on site, which is also good environmentally as there is very little transport involved – less than a hay mile!

Paddy as for long-handled forks, I’m tempted to say that it is not the size of your tool but what you do with it….but seriously it is odd that the short versions are almost universal here. We do have some long ones for anyone who prefers to use one, but few do. Personally I do find the long handles ones very awkward to use. Maybe it’s a question of what you are used to.

[Paddy Tobin]

Paul,

Re forks/tools, as we would say here regarding footballers: 'a good big one is always better than a good small one'

Paddy

[gote]

I doubt that a scyte is much more dangerous than the tool in use but:
A: Not all can use them (The difficult part is to keep them sharp) and it is much more work.
B: The decision to make is: Do I do this because I need excercise or because I want the grass cut?
We do the same thing but we usually cart the grass away to our neighbour's cattle.
Since we want as much seed as possible and our seasons are later we do it around September 1st just in time before the Crocuses.
It works well. We get a little more wildflowers in the meadow every year.
Göte

[Gene Mirro]

Paul, what do you consider to be the benefits of plunging pots?  I believe a moderation of soil temperature swings would be one.  What else?  And thanks for sharing your expertise on this forum. 

[Kristl Walek]

Gene,
Just a comment from a Wisley outsider who has been using plunge beds for almost two decades in a very tough gardening climate (-45C winters, mid-winter thaws, lack of snow cover).

Firstly I would say that my (coarse sand) plunge bed is without question THE most important and valuable thing I ever constructed for my business. At the end of the season, everything I can manage to fit in, goes in and is overwintered here. Seedlings that are too tiny to overwinter, trees, shrubs, bulbous material. Plants in pots, in flats, whatever. They are plunged to their rims in logical "depth of container" rows (for practial reasons). The bed is left totally exposed to the elements. I would say that no matter what kind of winter I have, the overwintering rate is very high (over 80%).

Very large, deep pots (when the plunge bed is full) get the same treatment, but are put in "graves" in the now-empty vegetable garden. Tight up against each other, backfilled with whatever soil is there. Overwintering here is also very high.

From my experience, I am not convinced that the sand plunge bed necessarily does a better job of overwintering just because the pots are in sand (except in a winter where there is a flooding problem in the area, and then the faster drainage obviously helps). However, the ease of doing the actual plunging makes the sand a better choice. It's a rather pleasant job in the late fall, working in the sand bed. Sand obviously has to be moist to do the work of digging well---so if there has been no rain, I will have to wet it down with the sprinklers before I start.

The picture I have posted is just a small section of the plunge---I am guessing it is about a 50 by 25' area.

Kristl

[Carlo]

Looks fantastic Kristl...is that a stone walkway down the middle? How deep is the bed?

[Carlo]

Oh, and are you plunging clay and plastic pots?

Obviously Wisley's bed (being raised) is a different beast altogether...

[Kristl Walek]

Hi Carlo,
Nice to find so many old friends on this forum....

The sand plunge is at ground level, yes, and is entirely sand. It's only my German/Slovakian obsession with logic and efficiency that compels me to line things up so that they appear to be other than what they are  So, no stone or other "hard" walkway, just a good, straight line in the sand every so many feet for easy access to the pots in the spring (when mostly everything is pulled out).

I don't pot in clay generally so no, there are no clay pots plunged, even on an experimental basis.

The bed is not very deep---as the initial intention when it was built almost 20 years ago was to plunge alpines in small pots. It's approximately 12-18" deep. Framed with railway posts.

When the sand level goes down (as it inevitable does every few years (sand ends up in the top of the pots, and I continually "steal" from it during the summer for potting, etc), the tri-axle load truck can back right up to the area and dump another load straight in. I then (feeling very Japanese-German-Slovakian), spend time raking it smooth and level to ready it for the next round of plunging.

Kristl

[Kristl Walek]

a P.S....

For gardeners in a cold climate, the plunge offers, I think, the best alternative to overwintering both established plants and young seedlings too small to safely overwinter any other way. In my experience, cold frames cannot even come close to what is possible in a plunge bed.

Kristl

[ChrisB]

I have just filled half of my (Alitex) cold frame with sand to create a plunge bed.  It has a brick base.  Don't know why I've never thought of doing this before.  Have taken one of the covers off and left one on, so I can have the best of both worlds - my floury auriculas can leaf successfully without losing their ?what is that stuff called? and I can control the amount of water I give to my bulbs whilst in the other side I can over winter more rain tolerant plants and seeds I shall sow this autumn.  Already there is not enough room!  I use the other side for very large pots that need winter protection, but I am now tempted to get another dumpy bag of sand and put it in there too.

[Maggi Young]

"Floury stuff" equals "farina... Ive said it before and I'll say it again... there's often a clue!

[Paul Cumbleton]

Thanks everyone for the discussion on plunges. I think plunges are really useful and so I intend to make the next Wisley Log all about them - so Gene I'll answer your question there this coming week.

[Lesley Cox]

A great new log edition. How wonderful to have a whole, brand new house to plant! The planting and the plants are superb. And the pictures too are amazing, a great thrill, like our own person show bench. Thanks so very much, everyone involved. I'm especially pleased to see the Empodium as I was given a potful of semi dormant bulbs recently. Something super to look forward to.

[alanelliott]

More of Gemma please now she's started so the rest of us students at RBGE can keep and eye on her!