What Is River Rock?
River rock is a type of limestone formed from sedimentary rocks such as sandstone, siltstone, shale and mudstones. It consists mainly of quartzite (a form of feldspars) which are common minerals found in rivers and streams. These types of rocks are often referred to as “river chalk”. River chalk is a very durable material when compared to other types of soil. It can withstand extreme weather conditions and it does not require much water or fertilizer to maintain its health.
The main benefit of using river rock for garden beds is that it provides excellent drainage and protection against erosion. It also acts as a natural barrier between the ground surface and the surrounding vegetation.
How To Use River Rock For Garden Bed?
It is advisable to choose a variety of different sizes of river rock so that they do not become compacted during heavy rains. A good way to ensure that your bed is well drained is to place a layer of gravel over the top. You may also want to add some crushed oyster shells along with the river rock if you have access to them. If you wish, you could even try adding pieces of driftwood or branches into the mix. This provides much-needed shelter for small insects and animals to access your garden.
Before you begin the planting process, you need to prepare the soil properly. This involves digging a hole for each plant that is large enough to accommodate its roots.
It is best to mix compost into the top layer of soil before adding the river rock. You should create hills with a slight depression in the center so that water can drain away from the base of the plant. It is very important to take your time creating a strong foundation for your garden because the roots of your plants cannot grow through river rock.
Before you add the river rock, water the soil so that it becomes soaked. You can then gently place the river rock around the base of each plant.
Spread a layer that is between 3 and 4 inches thick around each plant. It may sound like a lot but the plants will soon begin growing through it and covering it up completely.
You can then add a few extra layers around the top of the plants to ensure that the roots are completely covered. After this has been completed you need to add a final layer of gravel.
This will also aid in drainage although it is not essential and you could just leave it out if you wish.
The final step is to plant your seeds or young plants, making sure that each one is at the same level as the others. River rock is heavy so you will need to make sure that your plants are strong enough to withstand the pressure of the rocks.
Another important consideration is that some types of plants have roots that grow towards the surface rather than downwards. This means that they will end up poking through the river rock and ruining your hard work.
It is therefore best to stick to plants such as clover, which spreads fairly quickly and can help to naturally enrich the soil.
There are many advantages to using river rock in your raised garden beds and many different ways in which you can lay them out. You will need to experiment a little to find the design that works best in your yard but the results will be well worth the effort.
See more: How to plant a rock garden.
More Gardening Tips
You may also like: How to Create a Rain Garden, How to Build a Raised Garden Bed, How To Start A Vegetable Garden from Seeds, How To Start A Vegetable Garden from Transplants.
Sources & references used in this article:
The construction and configuration of Anasazi pebble-mulch gardens in the northern Rio Grande by DR Lightfoot, FW Eddy – American Antiquity, 1995 – JSTOR
The agricultural utility of lithic-mulch gardens: Past and present by DR Lightfoot, FW Eddy – GeoJournal, 1994 – Springer
The nature, history, and distribution of lithic mulch agriculture: an ancient technique of dryland agriculture by DR Lightfoot – The Agricultural History Review, 1996 – JSTOR
The cultural ecology of Puebloan pebble-mulch gardens by D Lightfoot – Human Ecology, 1993 – Springer
The landscape context of Anasazi pebble‐mulched fields in the Galisteo Basin, Northern New Mexico by DR Lightfoot – Geoarchaeology, 1993 – Wiley Online Library
Water accumulation in soil by gravel and sand mulches: Influence of textural composition and thickness of mulch layers by YJ Ma, XY Li – Journal of Arid Environments, 2011 – Elsevier
Calm active and focused: Children’s responses to an organic outdoor learning environment by S Nedovic, AM Morrissey – Learning environments research, 2013 – Springer