GROWING MEDIUMS
A growing medium is simply any medium in which your plants grow. As horticulture, both commercially and domestically, becomes more advanced, so the growing mediums used becomes more important. Similarly, the number and variety of growing mediums available commercially has increased dramatically. The choice of growing medium is a hotly debated subject and usually has no definitive answer. Each grower seems to end up with their own specific blend.
Here are some things to consider when choosing where to start:
What kind of hydroponic system are you using?
There are six basic variants and many sub-variants. (Drip System, Ebb & Flow, N.F.T., Water Culture, Aeroponics, and Wick). Different mediums have different characteristics. Cocopeat has excellent water retention properties but this is not a key requirement for Ebb&Flow designs.
What crops are you growing?
Small veggies like lettuce or micro veggies have a very different requirement to plants like tomato and peppers. My general opinion is that the smaller the plant, the smaller the individual parts of the aggregate should be. For instance a lettuce or spinach would not do well in a bed of large LECA balls.
Are you going the aquaculture root?
Mediums like perlite have a high ‘dust’ content which would not be good for the fish.
Do you want a consumable medium, or a reuse-able one?
Coco peat is difficult to separate from plant you remove and hence needs replenishing with each crop. It also has a limited life in terms of number of crops. LECA on the other hand is very effective as a more permanent medium.
Can you secure a regular supply and consistent quality of your chosen medium?
This is very important in South Africa. Exchange rate volatility can adversely affect your business model.
Do you have the time and space to make up your own mix?
How flexible do you need your set-up to be?
