Have you ever had a houseplant or outdoor annual that you potted and thought, “hmm, I’m a decent enough plant parent, but it feels like that died a little too quickly even for me.” You could have your plant in the right light, fertilize it properly, and water to its exact needs, but if the soil isn’t right, the whole operation crumbles and you’ve got yourself a deceased darling who didn’t have to be destined for such a dark fate. So, how can this be? Is choosing the right potting mix really THAT important? Sure is! Let’s talk about why.
Stop That Myth!
There is one common misconception out there that we should put to bed right now: soil is soil is soil. Actually, when you break it down, it’s not that simple. Potting soil has distinct characteristics and qualities that make it conducive to growing in pots instead of in the ground. The most important being, it is lighter! Garden soil has very little aeration and thus, it is generally heavy. Heavy soil can suffocate roots and inhibit proper drainage. A good potting soil mixture needs to be consistent throughout, and it needs to have a balance of moisture retention and drainage at the same time (generally”“this can vary depending on what you’re potting.)
The Main Components of a General Potting Mix
Most potting soils are going to have a few key ingredients:
- Sphagnum peat moss– for moisture retention and soil amendment. Peat moss helps with heavier soil and breaks it up to encourage drainage, while also assisting well drained soil retain more moisture. It also has a slightly acidic pH.
- Perlite- for moisture retention, pore space, and drainage. Perlite is lightweight and has a neutral pH.
- Vermiculite- increases porosity, adds magnesium, calcium, and holds moisture.
- Sand- adds drainage and weight.
- Limestone- neutralizes the pH of a peat moss-based potting mix.
It is crucial to remember that these are not the only ingredients you might encounter in a potting mix, and you may not even encounter all of these. The reason is that there are many different types of potting mixes for different plants, and they all have different components for different reasons.
Different Types of Potting Mixes
The reason why some soils have different components is because they are meant to assist in growing different varieties of plants. For example, a cactus is not going to want to grow in the same soil as a peace lily. We know this simply because one prefers water and one doesn’t.
Here are some potting soils to be aware of:
- All-purpose- for indoor and outdoor pots. Ingredients will vary depending on the brand.
- Indoor- intended for most houseplants, but watch out for any mixes that contain compost or bark, as they can bring in fungus gnats.
- Seed starting mix- a light, a soilless blend that encourages root development and drainage.
- African violet mix- somewhat versatile mix that is formulated for improved aeration, drainage, and retention. African violets like to be warm and moist, and this mix can therefore be used with other houseplants that prefer the same conditions.
- Cactus and succulent mix- contains sand and (commonly) perlite to encourage aeration to roots and heavy drainage. This is an important one to get right because cacti and succulents like to be on the drier side, and the heavier moisture retention in most potting mixes would not jive with these desert dwellers.
- Orchid mix– a soilless, bark mix that emulates their tropical rainforest habitat of growing on the bark of trees in tropical rainforests.
- Organic potting mix– contains all-natural matter with no pesticides or additives. This can be a great option for edible gardens with veggies and herbs, to give you an “all natural” garden.
These mixes are just the tip of the iceberg! We hope that after reading this, you will proceed with caution before using your leftover orchid mix to replant your African violet because that’s all you have left in your shed! Pot your plants with purpose.
If you have any further questions or wonderings about which type of soil to use for which plants, come see us at Salisbury Greenhouse. We have all the answers and products you need to meet your plant’s needs.