Potting Mediums for a Tolumnia

Bark

• Tolumnia orchids do well in fine to medium bark. Fir bark is perhaps the most common type because it doesn't compact when wet. This provides the orchid with adequate water and airflow. Fine fir bark is used for seedlings and miniature plants, like the Tolumnia. However, fir absorbs nitrogen and depletes it from the orchid, making high-nitrogen fertizlier necessary. It also begins to compact as it decays, so you must repot more frequently.

Rock

• Rock mediums are used for a variety of orchids because these mediums don't rot. Lava rock in particular is able to retain water without flooding the plant and allow for air circulation. Rock may be mixed with bark or another medium to add minerals and change the texture of the growing medium. It doesn't work well with hard water, as this over-feeds the tolumnia.

Other Mediums

• Other mediums can be used for potting tolumnia. Perlite is a fine volcanic material ground into tiny pebbles or a powder that mixes well with fine or medium bark and doesn't damage the orchid's fragile roots. Sphagnum moss is also very common on its own or as an additive. It holds water well, can be used live or dry and can inhibit fungal growth.

Additional Considerations

• Tolumnia needs repotting once its newly sprouted shoot reaches 2 to 3 inches in height. When repotting, always remove the old growing media, and snip off dead or decaying roots, foliage or blossoms. Plant the orchid 1/2 an inch beneath the medium, which should be kept moist until new roots are visible.