Rejuvenating the Rockery
14th July 2009

After the colourful display of spring alpines and bulbs the rockery can look tired and jaded in summer.

Stand back and take a critical look at it. Are parts of it overgrown with the more rampant plants smothering smaller gems? Are there patches with more bare soil than plants? Is it boring?
Don’t worry, you are not a bad gardener and you are not on your own. That is the nature of rockeries and they all benefit from an overhaul every few years.

Weeds sometimes go unnoticed especially if they are hidden under rock rose (helianthemum) or heather. Take the time to search them out removing them by root. Where grass or persistent weeds such as vetch or couch have become established then it is best to clear out that pocket of soil and replace it with a mixture of fresh, weed-free topsoil and grit.

Aggressive plants such as dwarf cotoneaster may need to be pruned back from slower growing alpines and if the plant is really too big for its allotted space then dispose of it and replant with something more suitable.

Some plants, such as gentians, Rhodohypoxis baurii and hardy cyclamen, will gradually take over more ground but without displacing plants already in position. Pruning and dividing plants will, once again, expose more of the rock that, hopefully, is worth looking at. Careful use of a pressure hose will freshen the rock without damaging plants.

Surface the soil with coarse grit. It will deter weed seedlings and act as a moisture retentive mulch while keeping the collar of alpine plants dry.

When replanting select plants that are slow growing. Gaps may be temporarily filled with autumn, winter or spring flowering dwarf bulbs.

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