Cymbidium leaf tip dieback & pseudobulbs not growing

[varda.elentari]

Hello everyone,

Several months ago I repotted a cymbidium into fine/medium size pine bark sold at a pet store. I've potted other cymbidiums in the same bark after soaking it for several days and had no problems. Unfortunately this time I rushed and skipped this step and now the leaves are dying back at the tips. I water with tap water that has been left to stand for a few days and flush out the medium prodigiously but it hasn't helped so far. I don't want to repot the plant again so what else can I do? Is there something I could add to my tap water to help flush out whatever chemicals are in the medium? Or is it possible that the medium ph is off? Should I test it?

The pseudobulbs haven't grown at all during the summer despite the fact that I put the plant outside. When I bought the plant and repotted it I found that the tips of the roots growing from the baby pseudobulbs had died because of insufficient water. I understand that means those roots will no longer grow. Could it be that pseudobulbs stop growing once their roots stop growing? Or did I simply not give the plant enough sunlight?

I'm relatively new to cymbidium culture so any suggestions would be much appreciated. Thank you.

[Cym Ladye]

It would help if you could post a photo. My suspicion is that you are OVERWATERING not underwatering the plant, especially since you say the new roots died on the new growth.

I do not know what the bark at a pet store is used for but if it has worked for you before, it was worth a try.

A few tips:
1) It is not necessary to soak bark "several days". I soak mine no longer than 24 hours and then scoop out with a sieve that which has floated and let it drain overnight. This is what I use. I discard that which has sunk and use it for mulch on other non-orchid plants.
2) It is best to underwater newly planted/divided Cyms. for as long as one month to stimulate root growth.
3) There is no need to let your water sit/age. If that were true, the commercial nurseries would be in a world of hurt!
4) I noted you live in Canada but what are your growing conditions? Where do you have your plant?
5) You say nothing of fertilizing. Cyms are voracious feeders, especially from late spring to fall. I would suggest a balanced (13-13-13) slow release granules to sprinkle per directions on the top of your plant. That way, the plant is fertilized every time you water. Simple way to start, but as you get more advanced in your growing, you can also get more complicated.
6) Once a pseudobulb gets its full compliment of leaves (usually 8-10) it then "plumps" up but it will not grow more leaves. Instead, it sends out a new growth from the side and if strong enough, a spike.

My advice for now is to apply a granular fetilizer and let the plant dry out for a month = NO water. It may sound drastic but the roots need to dry. Another more drastic step would be to pull the plant out of the pot and let the roots thoroughly dry for several days. Then repot in a bark mix more suited to Cyms. A good basic mix and ratio would be 80% fir bark plus 20% perlite. If you can get Orchiata near you, that is a good product that needs no soaking.

I hope this helps. It is as general as I can make it without seeing the plant and feeling the roots.

[varda.elentari]

Thank you for such an informative reply Cym Ladye! I can't post a picture at the moment but I can answer some of your other questions.

I suspect the new roots died because I wasn't watering frequently enough. I have rotten luck with cymbidiums in general: I've killed so many in the past. I've been able to save the ones I have now by putting them into containers with very loosely packed sphagnum and bark at the bottom which I would spray every day or two. The great advantage of this is that I can easily pull up the plant every once in a while to check on the root system. But I can't pot them like that permanently because the loose medium doesn't provide any support for the plant. (I had the bottom half in the container so the plant was leaning against the sides for support. So half the plant wasn't getting much sunlight.) Also, if I forget to spray the medium for a few days (and I am horribly forgetful) I risk killing the root tips. So once the plants grew some healthy roots, I potted them up in medium-fine pine bark but now I have no idea what's happening with the roots! I suspect the bottom half of the container is not drying out in between my weekly waterings but the top gets bone dry. Should I spray instead of watering? Or should I just go back to my sphagnum method? Or try a different medium?

In terms of my general growing conditions: I grow indoors for most of the year under a fluorescent fixture. In the summer, I put my orchids outside where they get 3-5 hours of sun in the morning and then again in the late afternoon. Its not quite enough for cymbidiums I think but its the most I can do on a north-facing balcony.

I water all my orchids once a week. Back when I first started growing orchids, I read that one is supposed to water until the water flows out of the pot for 20 seconds or so. I don't have the time to do that now that I have so many, so I put the pots in deep containers and flood them with water for 30 mins to 1 hour. I've been doing it for years and it works very well with my phalaenopsis, phrags and paphs. I don't keep the cymbidiums in the water as long as I do my other orchids, but is that still too much water for them? I think they'd do better if I watered less but more frequently, but that's not very feasible with my work schedule.

Btw, I also have mealybug problem with my cymbidiums. Not an infestation yet but they're there. Could that be related in some way?

---------- Post added at 04:59 PM ---------- Previous post was at 04:53 PM ----------

I forgot to to mention: the new pseudobulbs put out their 8-10 leaves but neither the leaves not the bulb grew to full size. They never "plumped" up.

[estación seca]

Many plants will almost stop growing if infested with mealybugs. You need to deal with that issue. And watering a Cymbidium with poor to no roots once a week is probably far too much water.

[Cym Ladye]

I fear you have many things going on here. As Estacion said, you need to get rid of the mealy bugs first and foremost. There are biological as well as chemical ways of doing this. I personally use Bayer 3n1 Insect and Mite Concentrate. Another is Spectracide Triazicide Insect Killer For Lawns & Landscapes Concentrate (HG-96400) (32 fl oz). Both are available at many garden stores here in the US as well as on Amazon. I do not know the shipping requirements for Canada but you can check.

If you want biologic control, others on this Forum can check in or you can go to the search bar at the top of this Forum and type in "Mealy bugs". These critters are most happy on inside plants with insufficient air movement and a failure to wash off the leaves.

There are several causes probably playing out here for your lack of success with Cyms. Firstly they have to be firmly potted or the movement will cause roots to stop growing from the bulb. Secondly, pulling them in and out of the pots does not help either. You an tell a happy plant by simply looking at the health of the bulbs and new growths.

If you will send a private email to goldcoastcymgrowers@gmail.com they will send you a full care sheet on Growing Cyms as well as their Complete
Guide to Repotting and Dividing Cymbidiums. This Guide was published in the CSA (Cymbidium Society of America) Journal several years ago and is an excellent guide for all Cym. growers. Many of the Forum members have sent for it. Gold Coast is a Branch of the CSA.

[varda.elentari]

Thank you. I'll stop watering for a month as you suggested and address the mealybug problem. I can't find any of the treatments you recommended in my area however. Would a mix of alcohol and soap work?

[estación seca]

Alcohol and soap will kill most of the mealybugs, and is better than not treating. But you will need to watch carefully and treat again as needed.

[malteseproverb]

Just in response to your original question about pseudobulb development: when I first started growing orchids with psuedobulbs I freaked out if new growth psuedobulbs wouldn't get as big or fat as the old growth, but I've since found that sometimes the fattening up of a pbulb takes nearly a year and can happen after it has put out flowers. I thought my smaller new growth meant trouble but often they have a lot of energy from the old pbulbs and are using the energy they get from the sky and water to put out roots or spikes. You have to be patient with orchids, they can grow so slowly.

In response to some of the other stuff: please deal with the pests, they are very serious. They will kill all of your other orchids. Also, you have to learn what the plant needs and how to read it in other ways than pulling it out of its pot all the time. No plant appreciates that and orchids less so. It can be stressful, but it's part of learning to raise orchids. People use bamboo skewers pushed into the soil as a way to measure how quickly their media dries out. Start there. I also never soak my potting media and it's always fine--I'm just lazy. Lastly, cyms are tough so take heart.

[varda.elentari]

Thank you for your words of encouragement. I know it's stressful on the plant to pull it up all the time so it's something I do only as a last resort. But I always have so much trouble with cymbidiums it seems I always come to the last resort measure.

[estación seca]

In my limited experience, serious Cymbidium trouble is due to some combination of too much water, not enough direct sunlight, or bugs. Next down the list is not enough water. They will grow without fertilizer but the things above stop growth.