Orchid Repotting Demystified Pt. 1
Repotting orchids doesn't have to be complicated and I'm here to help make the process easier to understand. I've decided to make a two part series, starting with container selection.
There are lots and lots of different kinds of pots to choose from and what you selection for your orchid will depend on its needs, most often how quickly it likes to dry out. There are many commercially available pots out there from ornate 'orchid' containers to your run of the mill plastic nursery pots. When choosing a container for your plant, consider if it likes to dry out between waterings, how often you like water your plants, your average relative humidity and average temperature. Below are the four types to consider (although there are many more to choose from):
- Standard clay pots - an oldie but a goodie. You really can't go wrong with a clay pot though you should be aware of its evaporative cooling effects in cooler and/or dryer climates as some warm growing orchids won't appreciate cold feet! Glazing on the pot can mitigate some of these effect and will also hold in more moisture.
- Slitted or hole-punched clay pots - These are most often sold as 'orchid pots' at the store. They can either be glazed or bare clay but both options provide exceptional air flow to the roots. These are good choices for plants that like to dry out between each watering (I.e. Cattleyas) or for the overly attentive gardener that likes to water often.
- Plastic pots - standard plastic pots can either be decorative or nursery type pots. I don't recommend overly deep pots in this category because it takes too long for the media in the center to dry completely. Choose pots that are close in their height and width measurements. Plastic pots are good choices for orchids that like to be kept moist or for the forgetful gardener.
- Plastic pots with slits - Much like their clay pot cousins, these provide better airflow to the roots but typically less than clay. These are good for plants that like to stay moist longer but resent soggy roots (i.e. Phalaenopsis).
In addition to choosing the right pot for your plant and conditions, you must also consider proper size. A pot that's too small will result in your orchid climbing out of it within a year. If the pot is too big then the media will retain too much moisture and risk rotting your plant's roots. As a general rule of thumb, the pot should allow for one year's worth of growth but not more than two. Going up the next 1'' to 1.5'' in pot size is usually sufficient.
Mounts and Baskets
In addition to pots, you can also grow most orchids mounted on a porous surface, typically some type of wood, or grown in a basket. I am putting them together in the same category because plants grown this way need to be cared for in a similar manner.
Growing orchids mounted or in baskets can be very rewarding, beautiful and good for the plants. The main problem that comes with growing orchids this way is keeping them properly hydrated. Sphagnum moss or other fibrous media can be used on the mount or in the basket to retain some moisture but plants grown this way will most often require waterings 2-3 times a week in humid climates or cold weather and daily or even twice daily in dry and/or hot climates.
Many orchids, such as Cattleyas, Vandas and Tolumnias prefer to to be grown this way and will thrive as long as their other needs are met. Since they prefer to dry out between waterings, they have naturally adapted to longer dryer periods and don't typically suffer from a missed watering here or there. Other plants, such as Oncinidae and Bulbophyllums can do very well mounted but will require more dedication. Plants that lack psuedobulbs, such as the Masdevallias and their allies should only be grown mounted in highly humid environments such as in terrariums or vivariums.
Terrestrial and rupicolous orchids very rarely adapt well to mounted culture. These include most slipper orchids and rupicolous Cattleyas such as C. milleri. I advise against growing this way with plants in these groups as it is rarely successful.
I hope you have found Part 1 of Orchid Repotting Demystified. Be sure to check out Part 2.