Tag Archives: rockery

From big picture gardening to small picture detail

Ours is not a rockery for growing alpines

Ours is not a rockery for growing alpines

My mission to weed our stream and ponds, about which I wrote last week, has been subsumed. That is to say it has largely been taken over by the menfolk in my life and turned into something much larger but I am not complaining. I was trying to clear the water weed. They are now building an additional weir, flushing the stream and hiring a sludge pump to clear the ponds. I know my limits. I have moved up from the park and into the rockery.

Moving from the open areas to the intimacy of the rockery is going from one extreme to another. The former is big picture gardening and much concerned with giving large trees space to grow and anchoring the whole picture well into the surrounding environs. This used to be called borrowed views and vistas before those terms became so pretentious they fell into naffdom. The rockery is all about little pictures, highly detailed gardening. I wouldn’t be without either, but I really enjoy the attention the rockery requires.

Traditionally, rockeries were about creating an environment that resembled scree slopes of mountains in order to grow alpines. We cannot grow alpines. We’ve tried but it doesn’t work. Our high humidity, high rainfall and mild year-round temperatures conspire against alpines. For us the rockery has become the place to keep track of treasures and to confine dangerous but attractive bulbs. Most gardeners know how easy it is to lose bulbs in garden borders. Some get swamped out by neighbouring plants, some are so anonymous when dormant that they get pulled out with other plants, some just seem to go, we know not where. If they have their own pocket in the rockery, it is possible to label their location and restrict competition.

Rockery conditions are surprisingly harsh. All that stone and other hard material heats up in summer so the soil dries out quickly. The gentle, steady rain we had last week didn’t penetrate very far. This means you have to be pretty selective about small shrubs, perennials and other plants but the bulbs don’t usually mind. In the wild, most are used to marginal conditions.

Too much of a good thing - Cyclamen hederafolium with black mondo grass

Too much of a good thing - Cyclamen hederafolium with black mondo grass

Two summers ago, I took the rockery apart pocket by pocket. At the time, I estimated there were about 500 separate compartments and it took me a full month’s work. At least I got to know it and all its inhabitants. This time I am only concentrating on the messy bits and the areas where plants responded a little too enthusiastically to the earlier renovation. The combination of black mondo grass and pink Cyclamen hederafolium is very pretty, especially as snowdrops come through the marbled foliage of the cyclamen in the depths of winter. But you can have too much of a good thing and all three inhabitants were trying to outcompete each other. I am thinning them drastically.

To garden in this style, you have to be willing to tolerate the messy season bulbs have, when their foliage is looking past its best. Most bulbs use the time after flowering to build strength below ground so they can flower again next year. When they have done that, their foliage dies down naturally. With some, this is a quick turnaround. Others, like nerines and colchicums, take many months. We just try and ensure that other areas of the rockery have more attractive displays to distract the viewer and leave the plants to their natural cycle.

I used to think that every pocket of the rockery should have something of interest in it all the time. This is actually a lot harder than it sounds because you then need to use a succession of maybe four different plants which can co-exist quite happily – and each compartment should have different combinations. In other words, for me this would be getting on for 500 miniature gardens. Rockeries are no place for mass planting. I flagged that idea – too hard and not necessary. Some compartments will have periods of the year when they appear empty and that is fine as long as there are no weeds. There is no place for any weeds at all in this intensive style of gardening.

Ours is an aged example – sixty years to be precise. We have some fine, gnarly, old, characterful dwarf conifers to give year round structure along with some smaller growing cycads (though somebody forgot to tell the handsome Cycas revoluta to stop growing). We have a few easy care, small perennials to soften the edges. A compact little blue campanula is one of the best of these along with a well behaved little scutellaria. We like the tall punctuation marks of some plants drifted through the rockery. The upright orange-toned orchid, Satyrium coriifolium, is the choicest one. The large flowered yellow Verbascum creticum seeds down gently to give the statement in late spring and the amaranthus (Love Lies Bleeding), similarly self seeded, is growing before our very eyes to fill the vertical accent role in autumn. These plants just provide a framework for the real stars – a succession of any and all interesting bulbs we can grow.

It means there is always something of interest to look at. I enjoy that sort of detailed gardening.


First published in the Waikato Times and reproduced here with their permission.

A Major Mission in the Rockery

The refurbished rockery looks a little barren in places but below the mulch are many bulbs waiting to spring into fresh growth

The refurbished rockery looks a little barren in places but below the mulch are many bulbs waiting to spring into fresh growth

My current activity started in a very minor way. I must thin out the Cyclamen hederafolium and nerines in the rockery, I thought yet again but this time I had my timing more or less right. The nerines look fantastic in flower in autumn but the clumps had become so large that they had forced themselves up out of the soil and the foliage hangs on right into late spring, swamping treasures around them.

What I did not realise when I started was that the task was going to be so major that I would spend eight hours a day for several weeks, taking apart the contents of the rockery pocket by pocket. It has become a Major Mission.

Cyclamen hederafolium is the autumn flowering species, formerly known as neapolitana. It is a gem which flowers over a period of months in white and, more commonly, cyclamen pink. After many years, decades even, they sure were overdue for thinning out. They grow from flattish, round corms and a large one is about 10cm across. Some of ours were closer to 25cm across and as I gently excavated, I found them up to three deep. In fact, my thinning exercise yielded up around 60 litres of surplus corms with which Mark plans to carpet woodland margins and add to his naturalised bulb hillside in the park. That is six 10 litre pots, in case you are wondering how I arrived at the 60 litre figure.

Having started, I found that the English snowdrops and black mondo grass which share some of the same rockery pockets were also in desperate need of thinning. And while I was about it, I figured the heavily compacted soil could do with aeration and a light dressing of compost. Then the rocks needed some of the lichen and moss scraped off them and some of the pockets had soil levels which overflowed. In fact a complete spruce-up seemed in order. And of course the areas which I did looked so fresh and clean that I felt I had to continue. I am still not finished but I am a driven woman and will not desist until I have done the lot. I have uncovered rocks and divisions in the pocket beds that we did not even know existed.

Rockeries are not in fashion these days, not at all. Ours is a 1950s style rockery using raised beds in island formation. There are a lot of rocks, brick and concrete in it and it must have been a major exercise to build. I had not noticed before that the largest rocks are in the beds closest to the drive. The further you go from the vehicle access, the smaller the rocks get and the more freeform concrete construction there is. I can understand why. Some of the largest rocks must have been very difficult to move.

The basic rockery concept is to emulate the conditions of an alpine meadow. We can’t do alpine, though we have tried. We lack the winter chill and are a great deal too humid with rainfall evenly spread all year. Alpine meadows are cold deserts kept dry in winter by a coat of snow and ice. So our rockery plants are by no means traditional. No gentians or edelweiss here. But what it gives us is a section of garden which is highly detailed, where the pictures are small and individual and baby gems can be admired in close up view. It is entirely different to the big picture style of garden where form, colour and flow are what dominate. Bulbs rule in our rockery, especially those of a miniature or dwarf persuasion. We use cycads, venerable dwarf conifers and some smaller growing perennials so the area is not totally bereft of woody and herbaceous plantings but they are merely the backdrop.

Best guess is that there are well over 500 individual pockets in our rockery. And the skill that has my gardening ability stretched to its absolute limit is the creation of differing combinations in at least some of those pockets. So one may contain nerines for autumn colour, moreas (peacock iris) for early spring and a small perennial such as a prostrate campanula for summer interest. I can not claim that I get triple layering in them all. I wish. Alas some will be bare during parts of the year because they are too small or I Iack the material or skills to plant in layers. But the structure provides the year round interest and does not demand to be filled to capacity twelve months of the year. Some bulbs will only flower for one or two weeks but in that time, they are the daintiest and most ephemeral of delights which would be lost entirely in larger garden beds.

Mark’s parents both loved the rockery. Stepping out from the house, there is always something different to view. Day to day maintenance is relatively easy. We have always worked to keep it weed free, to restrict the occasional invasive bulb (it is why one has separate pockets to keep those with wandering ways in a confined area) and beyond the occasional light mulch and ongoing tidying, it is not generally labour intensive. With most of it being raised, it is not back breaking either. Many bulbs are happy to continue in an environment which is relatively poor. But there comes a time when the soil is so impoverished and compacted that treasures start to go back and thugs multiply so much that the competition is to survive, not necessarily to flower well.

Bulbs are not gross feeders so we like to spread a thin layer of compost on top to mulch and give a light feed only. Not every plant is precious and that realisation has been wonderfully liberating. Some plants are past their use-by date. Some are just in the wrong place. Some have multiplied too well so there are too many of them. Going though centimetre by centimetre has been like a voyage of discovery. I have worked out that I can average about four square metres a day if I stick at it. With about 100 square metres of rockery, it is a mere 25 days work.

Some people like to garden in containers to keep little treasures apart and to be able to give different conditions. Despite my current intensive effort, I think the rockery concept takes less work overall for more aesthetically pleasing results. Maybe the rockery will stage a fashion comeback. If the thought of assembling, placing and securing all those rocks defeats you, there is an alternative in what we call the carpet garden, but for more thoughts on that garden genre you will have to wait.