Lately, there are pros and cons to covering soil of snake plant with coarse gravel or rocks. Is it a good idea or bad idea to cover the entire soil around a snake plant or succulent with rocks? What happens if the soil is more directly exposed to air and light? Is this relevant? It looks better to have rocks than black soil/dirt, but I wonder whether this would harm the plant.
While some people do not recommend it, many do. The most important thing is the type of potting soil mix you use. It must drain quickly and well. If not, then the plant will suffer regardless of the top dressing. It is important to make your mix grainy-gritty enough to provide good drainage and airflow.
There are those who argue not to use top dressing (rocks, grit, etc.) in very hot climates because it might get too hot. This may be possible. Despite the fact that plants come from arid climates, potted plants require a bit of attention. If I understand you correctly, soil – mix does not need to be in direct contact with sunlight. The plant does.
It is necessary for containers to have drainage holes. In general, glazed containers take a bit longer to dry. The same could be said for plastic. However, if one combines well draining mixtures with containers that have good drainage, it will make a big difference. The mix I use for succulents and snake plant is very gritty and inorganic, and I top dress it generously. I also top dress tropical plants with grit or small gravel.
However, there are people who claim that adding gravel to your pots is unnecessary. Here are the cons of covering soil of snake plant with coarse gravel or rocks.
Do Gravel Layers Improve Air Circulation?
Water passes through a coarsely textured material faster than it does in a fine one, so plants need good drainage so that their roots receive enough oxygen. Water does not easily move from fine to coarse textures, so rather than move freely and easily between the soil and drainage layers, it sits between the two layers and doesn’t drip until the soil is fully saturated.
Gravel Takes the Space
In an article titled Old Wives’ Tales, The Guardian reports that there is already so little space as plants are crammed into containers, and then gravels or crockery are added to provide drainage, which reduces the amount of soil available for root growth. In other words, you make a pot even smaller, which leads to an unhappy crowded plant.
Adding A Drainage Layer Causes Root Rot
Sue McDavid, a Master Gardener from the University of California, writes that plants like a good drainage system. The roots of plants will be damaged if water pools around them too long, which can lead to root rot. Over the years, gardeners have used Styrofoam packing material, gravel, broken pottery, and the like to cover the bottoms of containers. This should not be done… only the potting soil should be put into a container.
This type of drainage eliminates the need for water to run through soil, gravel, or other material and then out drainage holes wherever possible. Instead of flowing through soil, gravel, or other material, and then out drainage holes, water will completely saturate the soil. “This could take a long time, and in the interim, the roots of the plants will be deprived of oxygen.”
Gravel Adds Unnecessary Weight
The reason to avoid this is that gravel or pot shards at the bottom of a pot add unnecessary weight to the container since they are heavier than most lightweight potting soils and they become difficult to move.
What To Do
There is no need for a drainage layer, as Master Gardener Sue McDavid pointed out – only the potting mix should be put into the container. However, if you are concerned that the soil will wash away (which is also not going to happen) you can prevent this by placing a layer of paper towel or newspaper over the holes before you add the mix.
Those are the pros and cons to covering soil of snake plant with coarse gravel or rocks. It is up to you to use it or not. Now, what do you think? Is it a good idea or a bad idea to add gravel into your snake plant pots?