Brown rot on cymbidium??

[Noe]

I am new to this forum. I live in the San Francisco Bay Area. I just started growing orchids, bought some 6 cymbidiums, 5 phalaenopsis, two hybrids. I'm trying to teach myself how to grow them succesfulyy by reading and surfing the web for information. I think I need help from anyone who have more experience. My cymbidiums have black spots on the leaves and wet brown underneath. I think they are brown rot. The only fungicide I could find was Daconil. Can I use it? Should I cut off the infected leaves and saturate the healthy ones with it? Some fungicide mentioned was Physan and Captan but they are not available locally. where can I find them?

Another problem I got is the yellowing of the stem of one cymbidium. Is this normal?

[MothLover]

Wow, I have no idea. I'm suprised that no one has responded to you yet though, So I'll try to bump your post up. Hopefully someone with experience will help you out.

[JennS]

Check out your other post in the cymbidium section, there have been alot of replies.

[Des]

Cymbidiums can use a lot more moisture than most hobbyists realize , they must never be completely dry . looking at the media that you have for those plants I would say that they are too dry and that the media is of the wrong type for cymbids . Am I seeing correctly is there just garden soil mixed with a few pieces of bark?
If that is the case then I would suggest you change that to a mix that is designed for cymbids , check with your local garden shop they should stock a suitable mix . Or if you can find some try some coconut husk chips , I use it on its own and it works fine for me.
Spots on leaf tips usually means that the PH of the media in the pot is far too low 5.5 and lower To raise the PH you need to add some dolomite lime to the mix or to repot with fresh mix . if you are repotting into fresh mix then also add some gypsum to the mix , this will help to keep the PH within tolerance for some time In any case give your plants a top dressing of about a table spoon of dolomite lime per 200 mm pot (less for smaller pots) every 4 months and you will always have the correct PH within the pot . Cymbidiums do well if on a growing program.A Medium nitrogen fertilizer(hydroponic) Magnesium sulphate and calcium nitrate at quarter strength every time you water. If you need me to be more specific just ask.
I spray my plants with two different CONTACT fungicides
alternating every 4 weeks this keeps most most fungal infections at bay .Provention is better than cure!!
I have over the years grown to dislike insecticides as they not only poison the bugs but you as well!! But there are times when you have no alternative but to use the stuff . I am currently experimenting with repellants and sticky pads and must say that I am encouraged with the success I am having . I have been making my own sticky pads and inserting a small LED into the center of the pad this attracts the bugs to the sticky pad and to their DOOM!. Every week or so I repaint the sticky pad with PSA and it very effectivly carries on doing its job--Hope this helps you good luck

[Noe]

Thanks guys. Des, as a potting medium, I used a combination of orchid mix, fine and medium barks. I did not measure the proportion. I might have too much orchid mix. It looked dry but I have actually watered it 2 days before. Temperature here in the San Francisco is just soaring. I am planning to use another medium--just combining fine and medium barks, perlites, and charcoal. I don't know the proportion. Unless someone can tell me, I'll probably just try. I also ordered some PrimeAgra and will try it on another plant. I am looking for a fungicide for orchids but can't find them in the Bay Area. I am trying H2O2 I also got Fungicide 3 and Daconyl but have not tried them yet. I'll wait and see if H2O2 works. I'll check out the pH level. I should be able to pick up a pH meter.

[Des]

Noe , if your night temperatures are higher than 15 Centigrade then consider watering twice a day , you can also do as I do and stand your plants in a saucer of water. Even better is to get some of Rays SH pots and you will not have to worry about your plants getting to too dry . Cymbids just love growing in SH . Make a point of reading the SH information on this OB i can highly recommend this method of growing cymbids. I have been using SH for about 8 years now and my cymbids thrive .

[Des]

Oh and I forgot to say that I also use H2O2 in my feed water as it lowers the pathogen count of the water and at the same time oxygenates the water

[Noe]

Thanks Des. Can't wait to try SH. I did order some SH pots. I will share my experience. Re the temperature, I think in Fahrenheit. Will need to convert 15 C into it.

[Des]

Noe 15 c equals 59 Fahrenheit