Picking the right type of rock for your pond – and then using it imaginatively once you’ve made your selection – can make such a difference to the overall look and feel of that whole section of the garden. When it comes to the garden pond – and especially one in a small garden – any old stone you find definitely won’t do, at least not if you want a really attractive end result.
Fitting In With The Garden
One of the most important things to consider when selecting rock and gravel for the pond is how it will fit in with the rest of the garden. Unless your water feature is located in its own little setting and hidden away so you don’t see any of the rest of your plot, you’ll need to take any existing rockeries, scree gardens, gravel paths and so on into account.
In nature, the rocks in any given area tends to be the same; although you will sometimes find a wildly unexpected stone in an unusual area – perhaps dragged there by retreating glaciers – by and large, if an area is limestone, it’s limestone and that’s all there is to it.
The upshot of this is that although there is always a little variation in colour, all the stones tend to be similar harmonious shades. For some types of formal or architectural ponds, deliberately manipulating colours to make a striking contrast can work very well – if that’s to your taste and what you were after all along. If not, the effect can be rather jarring. Install a blue slate cascade alongside a Cotswold gold path, for instance, and the look will certainly be striking – but it won’t look very natural.
Again, it depends on what you’re trying to achieve.
For a very artificial, structured look, cut slabs or matched pieces will give any rock-work a very controlled and architectural feel, while if a more natural appearance is wanted, a mix of sizes will work best. A lot obviously largely depends on the size of your garden – there’s no point in getting things hopelessly out of scale.
As a general rule, if you’re going for a natural look, pick some rocks which are as big as you can realistically get away with – ideally something which looks too big to have got there by itself. This avoids one of the most common mistakes of rockeries and rock features – looking like someone just emptied out a barrow of rubble, or worse still, what many books call the ‘dog’s grave’.
Shape and Smoothness
The shape and smoothness of rock, stone or gravel needed depends on the intended use. Mostly it’s common sense: overly smooth stones used for pond edging may be dangerous when wet, while rough or jagged ones used within the pond – or left in a position where they’re likely to fall into it – could damage the liner and so on.
Some kinds of features have particular needs. For bubble fountains, smooth, river-washed cobbles are the best choice – avoiding anything which is much under an inch (25mm) across to get the right ‘splash’. If you’re looking to fill the bottom of a cascade pool or small artificial stream, however, smaller sizes of gravel are usually called for, since they take up less space and algae tends to grow less well on them than larger pebbles. It’s a good idea not to go too small, though, especially if your water flow is a bit swift, or you may find they wash out too easily.
Sourcing Your Rock
Most garden centres and pond specialists – and even some of the larger pet shops – either have supplies of suitable rock or can point you in the right direction to find some. It’s often worth spending the extra to get rock that is specifically intended for the purpose, to avoid the possibility of anything leaching out of the rock and harming your fish or plants. Generally granite, sandstone and slate are good, safe choices, while limestone can alter the pH of the water, so along with the likes of concrete and reconstituted stone, it’s probably best avoided.
Wherever you get your rock and gravel from, it’s essential to give it a thorough washing before use, especially if it’s destined to be used within the pond itself, to remove any potential contaminants which might be harmful to your pond.
Rocks and water features are natural partners; well done, they complement each other perfectly, so it’s definitely worth the effort to make sure you pick the best sort – whatever the final effect that you’re hoping to achieve.