Do you want to learn how to make your own homemade orchid potting mix?
As a new orchid enthusiast, you might be repotting because you've purchased a new plant from the store, or it's that time of year when you need to refresh the growing medium of the orchids in your care. Orchids are generally repotted in fresh growing medium every 1 to 2 years.
The signs that you need to repot are when:
- Your potting media are breaking down or decomposing
- Roots are overgrown
- Your plant is getting too big for its container
- The roots are starting to rot or become diseased
If any of the above happen, you will need a new container (or sterilize the existing one) and change out your potting medium. There are two ways that you can get new potting mix. You can either 1) buy it ready-made from the store, or 2) DIY your own.
It's easy to buy a mix from the orchid nursery or gardening shops. Simply tell them what orchid variety you have and buy the best media for that. At some point though, you'll be wanting to make your own.
Here's our step-by-step tutorial on how to make your own potting medium, specifically, bark mix. But first, let's ensure you know your basics.
Potting Media 101
Orchids are different from regular plants in that they don't need soil. Instead, they need good air flow and drainage. This is where potting mixes come in.
A good potting media should:
- retain moisture
- drain rapidly
- provide good circulation
- be slow to decompose
It's important to find the best medium for your orchid because it will:
- determine how much airflow your plant will get
- determine how much and how often you need to water
- directly affect the health of your plant
The thing about potting media is finding the best mix for your plant. There is NO one combination that works best for every orchid variety or grower. You'll have to experiment to find out what works best for you and your plants and actually that's part of the fun.
Common Potting Materials
Bark mix is a great potting medium because you come very close to mimicking an epiphyte's natural growing environment. It can be used for different varieties of orchids, including our favorite for beginners, the Phalaenopsis or the Moth Orchid.
Here are some common materials that you can use to make bark mix.
Fir bark comes in three grades: fine, medium and coarse. Finer bark holds more moisture and dries more slowly. Coarser bark lets in more air and dries faster. It is easy to get and cheap. However, it resists water at first and decomposes rather fast compared to others.
Tree fern is also available in grades. It drains fast and it is slow to decompose. However, it is expensive and has low ability to retain moisture.
Also called peat moss, sphagnum moss is recommended for terrestrial mixes. It is easy to get and it retains air and water. You have to watch out though because it can retain too much water if packed too tightly or when it starts to decompose.
At first glance, perlite looks like bits of styrofoam. Believe it or not though, it's actually volcanic glass, hence the name, volcanic popcorn. Because it is porous, it stores nutrients and moisture very well and yet drains excess moisture too. It is lightweight, non-toxic, free from disease, and inexpensive to boot. It can't be used alone though as it has a tendency to retain too much water.
Coco husk chips
Coconut husk chips are a good absorbent medium and decompose slowly. However, they don't drain as well as coco husk chunks or bark.
This is commonly used to line the bottoms of pots as they provide good aeration. However, if you are into green gardening, you might want to give this a pass as they don't decompose.
How To Make Your Bark Mix
A. General Recipe
There are three basic steps to mixing bark mix for your orchids.
#1 - Prepare your primary potting material (aeration)
Choose the type of bark that you will use. Remember that we're using bark because it will provide your plant with good airflow. You can choose from ground Douglas fir bark, ground coastal redwook bark, or Osmuna tree fern fiber, to name a few.
#2 - Prepare your secondary potting material (moisture-retention)
Next, it's time to prepare the materials that will help you retain moisture when you are watering your plants. You can choose from sphagnum moss, perlite, or coconut husk chips.
#3 - Mix everything
Mix both primary and secondary potting materials. A guiding ratio is 5:1, respectively.
If you are using Osmunda tree fern fiber, soak in water for 12 hours prior. Then combine with redwood bark at 3:1.
B. Fine Mix
This combo is recommended for orchids with small roots that like to stay somewhat damp like slipper orchids, oncidiums, or miltonias.
Mix the following at a ratio of 4:1:1, respectively.
- Fine fir bark, fine coco chips, redwood bark or fine-grade coco husk chips or redwood bark
- Fine charcoal
C. Medium Mix
This combo is good for Moth orchids, cattleyas, and most mature orchids. This is a good mix to choose if you're not sure what's best to choose for your plants.
Mix the following at a ratio of 4:1:1, respectively.
- Medium fir bark or coco husk chunks
- Medium charcoal
As you can more experience, don't be afraid to experiment with materials to use and with ratios.
Tips and Tricks
Here are some reminders before I forget:
- Terrestrial orchids often grow in sphagnum moss in bogs. Epiphytes grow on mossy limbs. Keep in mind when choosing materials.
- Terrestrial orchids usually require a denser mix, like that of sand and sphagnum moss.
- Stability is another factor to consider. For example, packing peanuts provide good airflow but they may be too light if used as bottom material for heavier plants.
- Botanists of the Texas A&M University recommend this Moth Orchid potting mix: 80% fir bark and 20% coarse sphagnum peat.
- Horticulturists from the University of Tennessee, on the other hand, recommend THIS Moth Orchid potting mix: 3 parts fir bark, 1 part perlite and 1 part chopped sphagnum moss.
Watch The Video
I didn't choose a video on how to make potting mixes because there's just too many varying ways to do it (and everybody's a critic!). Instead, watch this very helpful video on the different types of materials and their different properties.