What Are Garden Boulders?

The name for the small to medium-sized stones that adorn exterior areas is garden boulders. They may be marble or limestone, among others.
What Are Garden Boulders?

Written by Jonatan Menguez

Last update: 23 November, 2023

Garden boulders are detachments of larger rocks that, as a result of corrosion and the passage of time, adopt a smooth texture. In addition to garden boulders, there are other uses, like construction, paving, and decoration.

Because of their aesthetic qualities, these stones are often placed in different interior spaces. However, one place par excellence for boulders is the garden. There, besides the decorative aspect, boulders offer several advantages related to the control of humidity and weeds.

Find out how to use boulders in your garden, which is the most convenient type, and the benefits.

What are garden boulders and what are their characteristics?

A boulder, also known as a stone, is a piece of stone that has broken off from a larger rock. When in motion, this object can be transported by different natural phenomena, such as water currents, earth movements, or wind gusts.

The smallest version, pebbles, are usually found in riverbeds and streams, as well as on seashores.

Pebbles do not have a defined shape or size. When they’re smaller, they are often simply called stones.

Thanks to the corrosion generated by friction, they eventually adopt a similar morphology. They oscillate between rounded and oblong formations, although their most outstanding characteristic is the lack of edges.

In addition, the constant blows that their surface receives, generated by wind currents, water, and other phenomena, give them a smooth, polished texture without cracks. This condition gives this type of stone a very particular smoothness, exploited for functional use in construction and, above all, for the decorative aspect.

Size and classification

The granulometric scale, which measures and classifies sedimentary formations according to the grains, indicates that boulders have a size of between 64 and 256 millimeters. Stones of smaller diameter are known as pebbles, while those larger than 256 millimeters are known as boulders.

Canto rodado.
Boulders, stones, and pebbles acquire their shape after being exposed to climate and geographical conditions.

Different uses of garden boulders

Whether they come from basalt and are black, or white and from granite, these stones are used for numerous functions:

  • Construction: Due to their smooth texture, they are often used in different types of construction. In particular, they’re common in the elaboration of pavements. It’s common to see highways and roads with the presence of this material.
  • Plasters: They are also useful for wall coverings, since they have good adherence to cement and are easily stacked.
  • Decoration: There’s no doubt that boulders are pleasing to the eye. Their shape and texture give them a distinctive look compared to other stones. Architects and designers take it into account for decoration, both indoors and outdoors.
  • The garden: In home patios or yards, stones combine their aesthetic conditions with the ability to maintain humidity and the possibility of delimiting paths.
  • Archeology: Because of their resistance to the passage of time, scientific studies of material remains use them for dating according to human marks and movements in the ground.
  • Spas and relaxation: Their soft texture makes many relaxation sites use them to step and walk on them, thanks to the pleasant effect they generate. People also use them in massages.

The advantages of garden stones

In outdoor spaces, these stones have multiple benefits. They range from the organization and delimitation of spaces to the care of the soil, since it protects the substrate of the plants, preventing drought and the growth of weeds.


Boulders are good for patios, gardens, and green spaces to beautify the land from its uniformity, texture, and color. In this way, you can place them wherever you like. You can place them along paths or around plants, to improve the aesthetic aspect, for example. It’s also possible to reserve a space to place a floor of pebbles for walking on them, just like a spa.

Fill in spaces

If you have fountains, pools, ponds, or a watercourse in your garden, pebbles are ideal for filling in the surrounding spaces. Many landscapers use them in public places, forming an attractive combination between the passage of water and the texture of the stones. It’s also possible to place them inside fountains to decorate the bottom.

Garden pebbles protect the soil

When placed on top, boulders receive climatic phenomena and protect the soil to maintain the temperature during sudden changes. Particularly when the sun’s rays are strong, as they are highly resistant. Pebbles reduce the impact of the sun, allowing the humidity of the substrate to linger longer.

They form paths and can be used to line spaces

Combining the pleasant sensation of stepping on pebbles and their aesthetic aspect, they become a suitable material to form paths in the garden. If you have a large outdoor space, interconnecting it with pebble paths adds functionality and decoration.

It’ s also possible to separate and line different sectors of the patio with them, such as a swimming pool, a playground, or a vegetable garden. They combine very well with cacti or succulent plants.

Canto rodado para cactus.
Pebbles combine perfectly with succulents.

Types of garden stones

There are different types of boulders, depending on the size, shape, color, and the larger rock they come from. Choose the types of marble depending on personal preference and the needs of the garden. They’re very attractive, although with a high weight and traces of white dust. There are also smaller alternatives that are ideal for the decoration of ponds and fish tanks.

Placing them is very easy. It’s enough to generate the space to insert them after removing the soil and smoothing the ground.

It’s advisable to observe the weather forecast and make sure that there is no rainfall, since it can move the stones before they settle. If you want to produce better adherence, it’s possible to apply a layer of cement before placing the pebbles or stones. This way, they will be more fixed once they dry.

Choosing garden stones according to their colors

Although there is some uniformity in the different pebbles, they do vary greatly in size and color. Therefore, you can purchase options from rocks such as granite, limestone, basalt, or marble. They adopt gray, white, black, black, brown, or hybrid shades that are perfect to combine with some sectors of a garden.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.