The make or break of succulents
Succulents, and truth be told, most other plants as well, need a well-draining growing medium.
To start with – what is the actual purpose of a growing medium:
- It supports the plant and keep it upright
- Supply the plant with water, minerals (Food!) and air
Minerals – plants need food, just like us. And like us different plants have different requirements. Plants like tomatoes, that produce fruit, are hungry and need a lot of specific nutrients at specific times. Other plants like succulents, that have evolved over years under harsh conditions, have a lower requirement and some even thrive in poor soils.
Air – To put it simply – roots also breathe and there is a constant exchange of oxygen and carbon dioxide. If there are no air spaces in your soil, and it is a soggy mess, the soil will be anaerobic, meaning no oxygen. No micro-organism or earthworms will survive and the poor plant will die…
Again, different plants, different requirements but most succulents do not appreciate a soggy, wet mess to grow in.
There are heaps of scientific articles if you want to go deeper into it but let’s keep it simple:
I mix 4 parts of compost with one part of coarse river sand.
Why compost: It is a natural way to improve your soils’ physical, chemical and biological properties. Compost is rich in plant nutrients and beneficial organisms. An additional handful or two of bone meal can’t hurt as it is a natural slow release fertilizer.
Always use a good quality compost – if it smells it is usually not good quality….
Smelly compost is an indication that the balance in the original heap was off and you can even burn your plants. Smelly compost can be due to too much nitrogen, too much carbon dioxide or lack of micro-organisms. It is just not worth buying cheap compost and destroying all your plants.
How to ensure it is a good compost? Do a quick little test: Plant some cheap radish seed in it – they germinate extremely fast and is a good indicator plant. If the radish thrive, your plants should do well.
Just remember: Compost batches differ from one batch to the next. Even if they have a recipe, they never 100% use the same starting material and if demand is high they might not always wait till the heap is properly composted.
Cheap compost that has not reached a critical heat will also not have killed off all the weed seed and you might be very busy weeding to make your pots look good and to remove competition from your new little succulent.
Why river sand: It improves drainage which is critical for succulents. This might not be true for all plants as your pampered indoor plant might not enjoy a dry, fast draining soil.
Please ensure the sand is as coarse as you can get – a silt consistency is going to harm rather than help. Sand will also help to make your growing mix less “dense”.
Have you ever tried to take a plant out of a pot and the growing media sticks to it like glue? Over time your compost has broken down and all your air spaces have disappeared. And you wonder why the plant is dead?
Sand will ensure your mix stays nice and crumbly with lots of air spaces.
Stay away from building sand – there could be nasty chemicals in it, and it also has a high lime content wreaking havoc with your pH
There are hundreds of other types of growing media: perlite, vermiculite, peat and coco peat – each with their own pros and cons.
Mostly these media are expensive so please do your homework to ensure they are worth their money and that you are aware of hidden dangers.