Expert: Will Creed - 3/6/2007

Question

Hi Will,

Thanks for your prompt reply. As soon as I read it, it dawned on me. My other Epi, the one that is doing well, is potted in regular peat-based houseplant potting mix, not orchid mix. Duh!

I'm not very good at remembering to fertilize, in fact, my houseplants rarely receive fertilizer more than once or twice a year, if at all. I know you don't usually advise repotting but I wonder if in this case I should replace the orchid mix with a peat-based mix.  What do you think?

Alexis
------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hi Will,

My Epiphyllum oxypetalum has recently started to develop problems; older, lower leaves are beginning to pale and even yellow in some cases. I think it might be because of insufficient light - winters here are dismal and gloomy - but thought I'd better check with you in case I'm overlooking another obvious cause.

The plant is several years old. Because the original pot broke, it was repotted a couple of years ago into a same size (8") pot using a sterile orchid mix. Now that I think about it, I haven't been as diligent about fertilizing as I probably should be. Could that be the cause of the yellowing leaves?

I summer the Epi outdoors in the shade and take it in once temperatures drop to about 40F. It bloomed in the autumn of 2005 but didn't set buds last year, which I attributed to a move. The plant doesn't receive as much light in winter as it did in the former location. However, I'm not sure that is entirely the problem as another Epi is doing well. Both plants are allowed to dry out well between waterings.

Please let me know if I've left out any relevant information that might help you to diagnose the problem. Any insights you can offer are appreciated.

Regards,
Alexis

-----Answer-----
Hi Alexis,

It is always a pleasure to answer challenging questions from someone who is experienced with unusual plants.

It is odd that one Epiphyllum is doing well while the other one is paling somewhat. Try to determine what is different about the 2 plants - pot size, location, age, etc. That may give you a clue.

As you know, I am not a big fan of fertilizer, but in the case of Orchid potting mixes, fertilizing is more important. This is because Orchid mixes typically contain large amounts of bark chips that tend to absorb  more oxygen than other potting mix ingredients. So use a high proportion nitrogen fertilizer and see if that makes a difference. Also check the soil pH and make sure it is in the 5.0-6.4 range. If your local tap water is on the hard side, that may raise the  pH out of this range and make the nutrients inaccessible.

Please let me know if any of this is unclear or if you have any additional questions. If you would like to e-mail me some photos, I may be able to provide some additional insights.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. Ratings are the only compensation I receive for answering plant questions.

Visit my website at  www.HorticulturalHelp.com
  
Regards,
xoWill Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: wcreed@HorticulturalHelp.com  

Answer
Hi Alexis,

Thanks for the great rating and nomination. That helps keep me near the top of the Experts rating list.

I would opt for fertilizing more regularly rather than repotting. As you know, repotting is stressful, especially when you are replacing virtually all of the soil. The more porous Orchid bark mix is generally more suitable for Epiphyllum. But I also know you like to repot, so go ahead, but don't hold me responsible!

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. Ratings are the only compensation I receive for answering plant questions.

Visit my website at  www.HorticulturalHelp.com
  
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: wcreed@HorticulturalHelp.com