If you are to spend any amount of money on hard landscaping in the garden then it should be something that will last for years.
The most economical of the natural stones are sandstones, many from India and China. These come in various colours, the most popular being cream and grey, as well as different surface finishes; riven (generally the most economical), sawn and textured. Sandstone has a good slip resistance even as a sawn smooth slab when wet and this is why it is one of the most commonly used stones for landscaping in the UK.
There is a wide range of slab sizes so this paving can be laid in a random, more traditional manner or as a single size slab for more modern schemes. Grey slabs weather better and require less maintenance. The creams are lovely but look best when sparklingly clean, which really does mean lots of scrubbing and are best used in a situation in full sun where algae will find it hard to take hold.
Our own native sandstones are lovely and most are commonly called Yorkstone. New sawn Yorkstone is a lovely material with a slightly sparkly surface and lots of life in each slab. These work well laid both in a traditional and contemporary way but both look best pointed with an exterior tile grout at 3mm wide rather than more traditional sand and cement pointing. Reclaimed Yorkstone is never pristine and often arrives with holes or bits of old metal in and is never calibrated (in other words, sawn to the same thickness to make it easier to lay) is best laid in a random pattern with a conventional cement mortar. It will become slippery when wet as its surface has already been smoothed by many years of foot traffic where it was originally laid. It does add instant history to a scheme, though, and works well with reclaimed stock bricks, flint or granite cobbles.
The more expensive natural stones – granite, limestone and basalt – are often slippery when wet and should have a textured surface applied before laying. This can be a sandblasted or bush hammered finish: both create dents in the surface of the slabs to provide grip but this process does leave the slabs with a matt surface which can often seem a little lifeless. They can work well when combined with other slabs of a bright hue as a border or detail. Many of the best grey and cream slabs lie within the limestone range but all should be approved for use outside. Some limestone from southern Europe will not take the cold of an English winter and should be avoided as they will shatter in the frost.
But all materials, even manmade ones, will discolour and age over time, which in most cases helps to settle the scheme into its surroundings. Algae are the scourge of paving stones and there are many products available on the market to help deter growth. It is always a good idea to speak to the supplier you purchase your stone from for their advice on a cleaning product as natural stones tend to react in different ways to different cleaning agents.
Kate Gould is an award-winning garden designer and a regular exhibitor at the Chelsea Flower Show. This is the latest in her series of monthly posts on design tips for transforming small gardens: read the rest here.