Rock on – our rockery in autumn

Nerine sarniensis hybrids blooming in the rockery

Nerine sarniensis hybrids blooming in the rockery

When I am old and maybe decrepit, needing to draw in the boundaries of the garden, I shall fluff around in the rockery. I really enjoy this area and, as we enter autumn, my heart sings with the new season blooms.

Traditionally, rockeries are for growing alpines and sometimes retaining banks. However, we can’t grow alpines in our climate and our rockery is on the flat. It is pure 1950s vintage, built from a combination of rocks of various sizes, concrete and some brick, with sunken paths and raised beds divided into many hundreds of little pockets of soil. It is designed for highly detailed gardening and at about 20 metres by 10 metres, it is relatively large.

The purpose of the multitude of small beds is to keep bulbs separate and to confine the more invasive ones. Most of the pockets have two or three different types of bulbs in them to give seasonal interest.

There is always something to see, though summer is the toughest season. Because there is so much stone and the beds are elevated, parts of it dry out almost to dust. We have dwarf conifers, cycads, and a few other small shrubs to give both all year round structure and summer shade. There are a few smaller perennials and a limited range of annuals and biennials but generally, the rockery is about the bulb collection.

The range of nerine colours at one time

The range of nerine colours at one time

As we enter autumn, it is as if the rockery heaves a sigh of relief and leaps back into life. All the bulbs whose growth is triggered by autumn rains start to move.

As a general rule, we find that the species bulbs look better. They are usually smaller flowered and more delicate in appearance than the showy hybrids which can look out of scale and even vulgar in this particular context. The exception is the nerines which peak this month. While we grow some nerine species, it is the sarniensis hybrids that dominate. A few of these are of Exbury origin but most are the result of breeding efforts by both Felix and Mark Jury. The colour range is delightful – from white, through every shade of pink including near iridescent highlighter pink, to purple, corals, almost apricot, oranges and reds. Unlike the floristry business, we want shorter, squatter stems so that the heavy heads are held upright even through autumnal weather.

Cyclamen hederafolium

Cyclamen hederafolium

Also lighting up the autumn is Cyclamen hederafolium (formerly known as C. neapolitanum) which hails from southern Europe and Turkey. This is the easiest of the dainty species cyclamen to grow and it has gently naturalised itself here. It throws its first brave flowers up in January but peaks this month. It is one of a number of autumn bulbs that bloom first before the leaves appear. Others are most of the nerines, colchicums and Haemanthus coccineus.

Moraea polystachya

Moraea polystachya

The pretty autumn flowering peacock iris, Moraea polystachya, outdoes almost every other bulb with its long flowering season. It seeds down gently into the cracks between the rocks without becoming an invasive menace. Some of the ornamental oxalis also give extended displays of colour but not all oxalis are born equal and neither are they all born with good manners. The most reliable performers in our rockery are O. purpurea ‘Alba’, O. luteola and O. lobata. They have been here for decades and never looked threatening.

O. luteola and purpurea 'Alba'

O. luteola and purpurea ‘Alba’

Colchicum autumnale

Colchicum autumnale

Then there are the bulbs with a much shorter season. Colchicum autumnale makes a bold statement with its big lilac chalices held above bare soil. Hippeastrum bifida is a transient delight for us. We have it in both pink and red and the blooms look as if they have been touched with gold leaf when the sun shines through. The autumn flowering leucojum is one of the daintiest and prettiest of tiny blooms and the crocus also delight.

Autumn crocus (species unknown) with cyclamen hederafolium

Autumn crocus (species unknown) with cyclamen hederafolium

The rockery is not what I would call low maintenance. The more time I put into it, the better it looks. In spring I completely replaced the soil in maybe a dozen pockets in my efforts to eradicate the pretty but invasive Geissorhiza aspera. I do not lie when I tell you that we have battling it for well over 25 years, hence my extreme action in replacing the soil in the worst affected areas. We have to be vigilant on weeds, slugs, snails, narcissi fly and weevils. I wire brush the rocks from time to time to stop the moss growth from hiding their shapes. There is plenty there to keep me busy in my dotage and, with the raised beds, I can do a lot of it sitting on a stool. Sometimes it is the detail and the little pictures in the garden that delight.

024First published in the NZ Gardener April edition and reprinted here with their permission. 

5 thoughts on “Rock on – our rockery in autumn

  1. hillview400

    Hi,

    I think your mystery crocus is one of the various members of the Crocus serotinus group. There are a number of subspecies, one of which, salzmanii, is quite well represented in New Zealand and Autralia. Sometimes the darker strains are referred to as C. asturicus. Its all a bit of a muddle! The genus crocus is currently being taken apart using phylogenetics and lots of field work so your crocus may end up as C. salzmanii or C. asturicus.

    In my experience it is a rapid increaser but the flowers are a bit flimsy. BTW it hails from parts of Spain and North Africa.

    1. Abbie Jury Post author

      I think I once worked out that it was serotinus but then got stuck narrowing it down from there, so thank you for that information.

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