Cymbidium orchid back bulbs are the old, leafless bulbs that are typically removed during repotting. These bulbs can be used for propagation, and with proper care, they can produce new roots and leaves. In this article, we’ll explore the key steps to determine if a cymbidium back bulb is dead or alive, the best methods to encourage new growth, and the typical timeframe for new roots and leaves to develop.
Determining if a Cymbidium Back Bulb is Dead or Alive
The first step in working with cymbidium back bulbs is to assess their condition and determine if they are still viable for propagation.
Firmness
Check the firmness of the bulb. If it is soft or badly shriveled, it is likely dead and should be discarded. A firm, plump bulb is more likely to be alive and capable of producing new growth.
Color
Examine the color of the bulb. A green and firm bulb is a good indicator that it is still alive and has the potential to sprout new roots and leaves.
Encouraging New Growth from a Cymbidium Back Bulb
Once you’ve identified a viable back bulb, follow these steps to encourage new growth:
Potting
Pot the bulb in a suitable mix, such as orchid bark or a mix with pine bark and Canunda shell. Bury the bulb about halfway down in the potting medium, leaving the old husks on to avoid damaging the growth eyes.
Lighting
Place the potted bulb in a bright location and leave it alone for a few months. New growth will typically appear within 3-6 months.
Watering
Do not water the bulb until you see new roots and growth emerging. Once active growth begins, water sparingly to avoid rot.
Fertilization
Apply a slow-release fertilizer in the spring, and consider using a liquid fertilizer on the foliage if desired.
Timeframe for New Roots and Leaves
The timeline for a cymbidium back bulb to produce new growth can vary, but here’s a general overview:
- New Growth: Expect new growth to appear within 3-6 months.
- Roots: Roots typically appear after the leaf growth is several inches tall.
- Flowering: It takes around 2-3 years for the new plant to reach flowering size.
Troubleshooting and Tips
Removing Old Bulbs
Once the old back bulb starts to rot, remove it, as it can provide nutrients to the new plant while it is still in good condition.
Twisting
When removing the back bulb, twist it from side to side to avoid damaging the new growth.
Patience
Propagation from back bulbs requires patience, as it can take several years for the new plant to mature.
Contaminants and Chemicals
Scale and Insect Pests
Remove old leaf husks to prevent harboring scale and other insect pests.
Fungicides
Use fungicides to prevent infection on cut surfaces.
Steri-Prune
Apply Steri-Prune or similar sealing pastes to seal cut surfaces and prevent infection.
References
- Cymbidium Back Bulbs
- Growing Back Bulbs
- Striking Back Bulbs
- Advice for Novice Growers
- Cymbidium Back Bulb Propagation
By following these guidelines, you can successfully revive and propagate your cymbidium orchid back bulbs, leading to the development of new, healthy plants.