Filling Pots and Planters in a Tropical Container Garden
and why you shouldn’t fill them with regular garden soil
So you made the first step and purchased your pots and seeds to get your veggie garden started (yay, WFH Phase 2 Heightened Alert!). Now you scratch your head because you can’t quite figure out what to fill your pots with. Veggie Mix, Potting Substrate, Soilless Medium, Free Draining… what do they even mean? How do you tell what good or isn’t? Is heavier soil better value for money? If you are feeling confused about it, don’t worry — because we did too!
We rounded up some of the information that helped us, and we hope it comes in handy for you too:
1. Different Plants, Different Needs
When filling pots and planters in a tropical garden, the most important thing to remember is that different plants have different needs when it comes to fertility, moisture and drainage. Their needs will also differ during their life cycles — seeds would require more frequent watering than mature plants, for example.
So before deciding what to fill your pots and planters with, decide what you will be growing first. Pick plants with the same soil needs if you are planning to grow multiple plants in the same container.
2. Use A Soil-Less Growing Medium As A Base
A soil-less growing medium looks like soil, but contains none of the inorganic material — sand, silt, or clay, that regular soil has . It is made primarily of peat, wood chips, or coco coir, perlite and/or vermiculite, and often a slow-release fertilizer including compost and/or vermicompost. They are a perfect option for tropical container gardens for a few reasons:
They are very light, so it is easy to shift your pots around.
Coco-coir based soilless growing medium are especially great because they drain well i.e neither too fast (so your plants cannot absorb the water and nutrients) nor too slow (so your plant roots sit in moist conditions for too long). They essentially hold on to moisture without being waterlogged, and enable plant roots to thrive well.
They do not compact easily, unlike garden soil, and will not cause the roots of your plant to choke
3. Mix It Up So It Fits The Needs Of Your Plants
Going back to point 1, different plants have different needs. While soilless mediums are a good base to start with, they may need some amendment to create the growing conditions required by certain crops.
For example, if you are growing mediterreanean herbs like Rosemary and Thyme, you may need to add perlite, sand or fine gravel for extra drainage. Fruiting crops like tomatoes and cucumbers are heavy feeders, so you’d need to add bone meal or compost to the mix. Add 1 part compost for every 3 parts of soilless mix, so you maintain the porosity and well-draining properties of the mix.
4. Keep It Biologically Active
As they are growing in containers, the mix you use tends to be lacking in the beneficial soil life and ecosystem that is present when you grow out in the open field. Beneficial micro organisms are the unseen workers that help to break down the essential nutrients in the soil so you plants can take them up, and also colonizes the surface so it keeps bad microbes at bay. Keeping the soil biologically active keeps your plants healthier and starves off fungal diseases. Having compost and vermicompost in the mix is helpful because they are filled with all the good guys. You can also feed your soil with a diluted seaweed solution to provide micro nutrients and additional beneficial microbes to keep it biologically active. We also like to ‘chop and drop’, where we leave some of our trimmings on the top soil layer so the break down and feed the soil.
Choosing a growing medium is one of the most important things to consider when creating a tropical container garden. It can be far more complex. But generally speaking, thinking about the above options will be the best place to start. You got this!