A Dried up Riverbed

[Palustris]

The Dried up River Bed.

   There are not many people who can claim that their latest alpine plant growing area came about because they always wanted a Yew hedge.  I have spent many hours in various National Trust properties admiring and envying the beautiful Yew hedges. Up to the beginning of last year, there was nowhere in the garden where we could put one, so it remained a dream. However, while visiting a local nursery we discovered that they were selling off 3  feet tall yew plants at £15 for ten plants. Now that was just too good an opportunity to miss, we bought 10.
   At the northern corner of our garden we have a small wood. The trees are actually Damson and the ground under them is full of a Galanthus nivalis form. I wanted to extend the area in which the snowdrops grew so I spent part of the winter clearing away the brambles and ivy from the section nearest the boundary. This opened up the wood to the strong winds which cause a lot of damage to our garden in spring. The clearance also left us with a length of fence with nothing growing up it. It was just about the right length for the yew trees! I fastened windbreak material to the wire netting which is the boundary fence to give the trees chance to establish before they had to brave the icy blast.

[Palustris]

Now those who have read about our gardening here in other articles will perhaps remember that the soil in this part of the garden is best described as a mixture of broken glass brick rubble and leaf mould with a sprinkling of scrap metal. Therefore, I had expected to have to do a fair amount of work to clean it up before planting. In went the fork, spades are no use in this kind of soil. Clang!  Every where I pushed in the fork, after about 6 inches depth, I hit something solid. I cleared away the 'soil' removing as much of the nasty stuff as I could while doing it. Just below the surface I came across rocks.
   That is not unusual in this garden, almost everywhere we have dug we have found 'rocks'.    They are almost all the rounded pebbles one finds on beaches or in river beds. The area was once a glacial lake and the fields round us are full of this material. We think that as the fields have been cultivated, any unwanted material has been dumped on the waste land which is now our garden. Mind I always worry that we have found something of archaeological interest, until the ubiquitous HP sauce bottle turns up, below the pebble layer. So, after a weeks digging and removing this is what I had. There were also a large number of broken house bricks, slates and other such material. This was taken to the local Recycling  yard.

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   The rocks themselves I stored behind the compost heap until I had decided what to do with them.

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   Fortunately/sadly, early on in the winter we had something of a disaster. The temperature dropped from plus 8c. in a rain storm to minus 8c, in something around two hours. To show what effect that kind of weather can have, we lost all our sprouts (vegetables in an Alpine article! Heresy! } and cabbages. The plants simply exploded. When spring arrived we also discovered that the weather had wiped out all the hebes in part of the garden. That was quite a blow as they were all grown from wild collected seeds and thus irreplaceable. However, it did leave us with an area where we needed to do something to fill the empty space. The area faces south east and is well sheltered from every other direction by plant covered trellises

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   The other side of the path from this was already an area of gravel, which has to be kept that way to allow access to the Septic tank when it needs emptying. It also was a useful place to put the rocks before placing them in situ.

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   Then came the problem of deciding what we were actually going to make with these rocks. Most of them were less than a foot by a foot by a foot. There were 5 or 6 bigger ones and a lot of much smaller ones, down to gravel size. Since they were glacially  deposited they are of very mixed  origin which makes creating a conventional 'Rock garden' a little difficult.
   We discussed various options with one or three 'experts' and the best suggestion was made by Vic Aspland. He thought that the material looked rather like the sort of rocks on found at the top of a beach. That is what we set out to re-create.
   After clearing off the top soil we discovered that, as is often the case in this garden, the subsoil was a nice mixture of coal cinders and brick rubble. It does make building alpine areas so much easier when one does not have to spend hours digging drainage material in.
   The first action then was to make a barrier between the new feature and the garden area behind it. Since it was intended to look like a beach and we had some lengths of logs I made my version of a groyne

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   Then we began trying to place the rocks. This was much harder to do than we had anticipated.

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   No matter how we tried, it always ended up looking like a conventional rock garden. So after a few head scratchings and rock moving around and cups of tea, finally we changed the design a little to making a dried up riverbed. We placed the largest rocks first.

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   You need to imagine the water flowing from the top right of the picture, down to the path, through various little channels. You need a good imagination though!
   Now it was just a question of adding the rest of the material.

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   Since this was to have been a beach scene we had bought a load of  ballast to use as filler. This is a mixture of 25 mm gravel and sharp sand. I also added  equal quantities of 12 mm. shingle (rounded gravel) to it. This mixture was spread over the area between the rocks. The sand is a rather bright colour, but it was all that was available. It is river sand so it does not contain any lime.

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   The next layer was sharp sand and 5 mm. grit in equal quantities.

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The final layer is a mixture of 12 mm. gravel and some larger pebbles.

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   The same sort of construction was continued on the other side of the path, except that since this was already a gravel garden and extremely well drained we did no more than scrape the gravel away, place the rocks and cover the area with sand.

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   Now comes the interesting part, planting it up. For the first time ever though, I have not had plants in mind during the construction.


















The finished construction.

   The 'soil' is about 4 inches of sand over gravel and extremely well drained. It will need careful thinking about..
   Paul Cumbleton (Senior Supervisor of the Alpine Section at Wisley) very kindly suggested the following plants. I will have to go looking for some of them.
   Aquilegia jonesii Aquilegia laramiensis Aquilegia saximontana Aquilegia scopulorum Aster coloradoensis Astragalus coccineus Epilobium rigidum Eriogonum cespitosum Eriogonum douglasii var meridionale Eriogonum flavum var. piperi Eriogonum gracilipes Eriogonum kennedyi Eriogonum kennedyi var alpigenum Eriogonum kennedyi var kennedyi Eriogonum ovalifolium Eriogonum ovalifolium var. caelestinum Eriogonum ovalifolium var. nivale Eriogonum siskiyouense Eriogonum thymoides Eriogonum umbellatum Eriogonum wrightii ssp. subscaposum Hymenoxys acaulis Lewisia nevadensis var rosea Lewisia pygmaea Lewisia rediviva Penstemon californicus Penstemon davidsonii var. praeteritus Penstemon eriantherus Penstemon eriantherus var. redactus Penstemon eriantherus var. whitedii Penstemon humilis var. humilis Penstemon jamesii ssp. jamesii Penstemon janishiae Penstemon nanus Penstemon newberryi f. humilior Penstemon ophianthus Penstemon thompsonii Phlox hendersonii Phlox hoodii Phlox hoodii subsp. muscoides Phlox longifolia ssp. brevifolia Phlox opalensis Phlox pulvinata Phlox speciosa Primula rusbyi Silene californica Silene hookeri ssp bolandieri Townsendia condensata Townsendia exscapa Townsendia incana Townsendia leptotes Townsendia mensana Townsendia parryi Townsendia rothrockii white-flowered Townsendia spathulata Viola pedata

[greenfinger]

Nice work, homo ludens! This kind of one's own experiences with trial and error is what magazine readers like most.
Success with the choice of the plants. In French there is a saying: "embarras de choix". When there is a lot to choose from it sometimes is difficult to make a choice.

[ideasguy]

Flower Genie Version 2 is finished, and what an excellent list of plants to start testing it with, Eric.

First one for me to research - since its a member of my favourite Genus, Primula rusbyi
Its all over the internet! Some great photos.
Of particulat interest, since your thread is Alpine garden related, is this one:
http://www.auriculas.org.uk/Show_pictures_04.htm

How can anyone fail to love primulas - gorgeous!

I had a quick lookup in RHS Plant Finder, and my RHS A-Z encyclopedia, when you posted your article, and found that many of the plants were not listed - they must be rather unusual. But, I'll research each one using Flower Genie and Google. Great test material.

[Palustris]

They are all American and as far as I can find out, you would need to find a source of seed for them. The various seed exchanges of the Rock garden societies would be best.
I shall probably add a rider when I send the article off.
I am waiting for a while, so that I can ask at the first Alpine show I am going to, next month sometime.