Potting and Tips
By now, you have realised that an orchid's potting needs differ exponentially from your average plant, but knowing which medium to use can be a headache to both the experienced and inexperienced grower. In this section, I'll try and generalise as much as possible to make decision making as easy as possible.
Also, please note the following few aspects which are essential when repotting. Repotting your orchid might cause some stress to the plant, so it is a good idea to fertilise after doing so. Except for a sick plant, you'll most likely only need to repot your orchid every one to three years. Another thing to keep in mind is to only repot once you have gotten new growth and their roots are about 3-5cm long. The same goes for keiki's, although I prefer to let the keiki's roots get to 5cm or more.
The following is a basic guide to repotting:
Step 1. You'll need to know what your orchids growing conditions are in the wild.
A terrestrial plant is a plant that grows on, in, or from land.
Although we may think of terrestrial plants as plants that simply grow in soil, many of the terrestrial orchids we'll cultivate in our collections grow on soil with its root system digging into leaf litter, mosses and other plant material.
The medium should still consist of freely draining, airy potting mix, but should also have considerably smaller particles.
Lithophytes are plants that grow in or on rocks.
When we think lithophytic, we think rocks, mosses and airflow. This means that potting medium should consist of larger stone or perlite components and a few pieces of organic matter like bark and sphagnum moss. Excellent drainage and air around the roots are critical with these types of orchids. A debatable piece of advice would be to drill holes in your pots before potting your orchid. I've done it with many of mine, and it seems to work.
Epiphytes are plants that grow on other plants.
With epiphytic orchids, you might think bark mix and that's that, sadly no, not really. As I have said, many times before, throughout this site and you'll hear and read about it all over. "It depends on the genus and species". You would most likely not go wrong with a plain bark mix, but adding some moss, perlite, stone, etc. might be the difference between a regular and an exceptional orchid.
Step 2. You'll need to know from where your orchid comes
Knowing where in the world your orchid is from would help you make educated decisions when choosing both the correct potting medium and placement of your orchid. Not knowing could be like playing a game of Russian roulette. It might work, and it might not. It would most certainly make a difference in plant growth, flowering routine, and so on.
The other aspect that comes with the location is humidity. Many species that come from the tropics need at least 60% humidity, and without it, the orchid would almost certainly start showing signs of stress like the shrinking of pseudo's or leaf tips turning black.
Average seasonal temperatures, altitude, rainfall patterns, etc. all play a significant role in the optimal success of growing and reflowering your orchids.
You might be thinking that you're the coolest kid on the block cause your Den. Nobile reflowered with a bloom per node, but the optimal would actually
be 2-5 blooms per node. On the other side, you might wonder why your Den. is pushing out "kieki's" and not flowering? Well, its because you're watering
it too much and you should let it go through a winter rest.
Optimal is the key to success!
Step 3. Choosing the right pot ... or basket or mount.
This topic feels highly underrated if you weigh it up against the potential risks you might face with the wrong choice. If you are just starting, I'll highly recommend beginning with an orchid that works in a pot. So let us get into it.
When shopping for orchid pots, you'll find many to choose from. Some are for aesthetics, while others have functional differences and advantages. Which to choose will come down to the type of orchid you have.
Plastic Pots – Plastic pots retain more moisture in the potting mix. They also can help keep the roots warmer in cooler climates. Plastic pots are very lightweight and can tip over easily with tall, top-heavy plants.
Clay or Terra Cotta Pots – Clay pots are heavier, leading to less tipping. They can also help keep orchid roots cooler in warm climates. Many clay or terracotta pots have only one drainage hole, but I have seen a few with multiple big holes on the sides as well. The clay breathes and allows water to evaporate quicker; therefore, you may have to water more often.
Wooden Slatted Containers or Baskets Baskets – Depending on what potting media you use, it can spill out of slats in wooden slatted pots or baskets, so you might want to line them with some moss. Wooden slatted containers or baskets allow for plenty of drainage and airflow to the roots, so you may have to water them frequently. When considering one of these options, be sure to keep in mind that they do best when hung.
The most commonly used materials are tree-fern slabs and cork tree bark. These are, however, not the only options out there, but work and they work well! Please keep in mind that caring for a mounted orchid is not as easy unless you have a greenhouse. They tend to dry out very fast and would need to be watered multiple times per day in summer. Adding some moss to the mix will help retain some moisture, but be careful not to overdo it.
Step 4. Potting mediums.
Bark - Fine - This mix is great for seedlings and fine rooted orchids.
Bark - Medium - Great for orchids with larger roots. Keep in mind that bark will retain some water.
Bark - Large - Large bark pieces are great to work into a potting medium for medium to large plants. It will help create air pockets for the roots and enhance drainage.
Fir Bark - Fir bark retains more water than regular bark and works very well for seedlings and some moisture-demanding.
Keep in mind that bark is 100% organic and will decay over time. As it breaks doen it might end up suffercating your orchids roots if left for a long period of time. Decay organisms will also compete with your orchid for nitrogen.
Because stone doesn't decompose, it remains porous and intact, unlike woody media which typically break down. In this way, the risk of root damage from overwatering or suffocation is reduced. Stone, however does not retain water, and thus rapid drying could be a problem. Orchids potted in stone should be fertilised more regularly due to the lack of organic material.
I have found that replacing some bark with medium grade stone can help reduce root damage in many orchids as the medium dries out quicker and retains a little less water overall. (Excluding Phalaenopsis)
Lava rock, like stone, does not break down, but is lighter in weight and retains some water. It is said to hold on to fertiliser salts too, so you should reduce your dosage to a 1/4.
Aliflor is a very lightweight clay product. It is porous, reusable if sanitised, long-lasting and can be used alone or in a mix.
Although it is a little heavier and slightly bigger than Aliflor, It fulfils much the same goal as Aliflor and many others. I'll add that growers prefer to use this alone rather than mixing it with other elements.
Sphagnum Moss/Sphagnum Peat Moss
Mosses do an excellent job of retaining water. It works well as an addition to your own homemade potting mix. Different ratios should be added depending on the orchids moisture demands. Moss is also prefered when mounting orchids
Perlite fulfils much the same role as stone but is much lighter. It makes a great media when potting small/micro orchids like Oncidium 'tiny twinkle' which has fine, fragile roots.